Co-reporter:
Journal of Applied Polymer Science 2017 Volume 134(Issue 8) pp:
Publication Date(Web):2017/02/20
DOI:10.1002/app.44506
ABSTRACTNovel waterborne UV-curable polyurethane containing long fluorinated side chains (WUVFPU) was prepared and the fluorinated component was incorporated by two novel fluorinated macromolecular diols (FDO) with different chain length as chain extender. FDO was synthesized via free radical polymerization of hexafluorobutyl methacrylate (HFBMA) using 1-thioglycerol (TG) as chain transfer agent. Extremely low dosage of FDO incorporated could change the surface property significantly. The influence of both the content and chain length of FDO on the surface energy, surface composition and morphology were investigated by contact angle measurement, XPS and AFM. Surface energy significantly decreased at extremely low concentration of FDO. The hydrophobicity was enhanced with increasing both the content and the chain length of FDO. XPS and AFM results revealed the enhancing hydrophobicity was attributed to the enrichment of F atoms and rougher surface morphology. Gel content, pencil hardness, adhesion, and optical transmittance tests were employed to investigate the coating properties of the UV-cured films. The preparation and investigation of WUVFPU might provide better understanding of the influence of fluorinated chain length on the properties of polyurethane for theory. Moreover, it might provide a facile and effective route to prepare polyurethane materials with low surface energy for engineering and industry. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44506.
Co-reporter:Jianquan Tan, Weiqu Liu and Zhengfang Wang
RSC Advances 2016 vol. 6(Issue 41) pp:34364-34375
Publication Date(Web):30 Mar 2016
DOI:10.1039/C6RA02433E
A series of waterborne UV-curable comb-shaped (meth)acrylate graft copolymers containing long fluorinated and/or siloxane side chains were synthesized by conventional radical copolymerization of a novel mono-methacryloyloxy terminated fluorinated macromonomer (PHFA-GMA) and/or polysiloxane macromonomer (SiOHMAC) with (meth)acrylate monomers. The separate effects of PHFA-GMA and SiOHMAC, as well as the synergic effect of these two components, on the properties, especially the surface properties were investigated in detail. A hydrophobic surface could be obtained with extremely low content of PHFA-GMA and/or SiOHMAC due to the strong tendency of the macromonomers to migrate towards the outmost layer, resulting in abundant enrichment of fluorine and silicon atoms on the surface. XPS (X-ray photoelectron spectroscopy) results revealed that for a given weight of the two macromonomers, Si atomic concentration of the copolymer modified by SiOHMAC is higher than F atomic concentration of the copolymer modified by PHFA-GMA. AFM (atomic force microscopy) images showed that surface of the copolymer modified by SiOHMAC is rougher than that modified by PHFA-GMA. Compared to PHFA-GMA, SiOHMAC had higher efficiency and effectiveness in creating hydrophobic surfaces. In addition, the influence of PHFA-GMA and/or SiOHMAC on the physical properties, such as water dispersion particle size, water absorption, pencil hardness, adhesion, mechanical properties and thermal properties were also investigated. The novel comb-shaped copolymers prepared via conventional radical polymerization not only had excellent properties but also have potential applications in large scale industrialization.
Co-reporter:Jianquan Tan, Weiqu Liu, Honglei Wang, Yang Sun, Shijian Wang
Progress in Organic Coatings 2016 Volume 94() pp:62-72
Publication Date(Web):May 2016
DOI:10.1016/j.porgcoat.2016.01.027
•Novel fluorinated macromonomer and comb-like acrylic copolymer was synthesized and characterized.•Excellent surface property was obtained with very low content of macromonomer.•High fluorine atomic content was observed at the surface.•The comb-like copolymer is promising in large scale industrialization.A novel waterborne UV-curable comb-like (meth)acrylate graft copolymer containing long fluorinated side chains (UVWCAC) was synthesized by conventional radical copolymerization of a novel mono-methacryloyloxy terminated fluorinated macromonomer (PHFBMA-GMA) and (meth)acrylate monomers. GPC, FTIR and 1H NMR were employed to characterize the structure of the polymers. The influence of both the molecular weight and concentration of PHFBMA-GMA on the properties of UV-cured films was investigated. Hydrophobic surface could be obtained with just small amount of PHFBMA-GMA copolymerized into the polymer. The surface energy of UV-cured films decreased as both the concentration and the molecular weight of PHFBMA-GMA increased. The surface composition of the graft copolymer was characterized by XPS. XPS results confirmed the enrichment of the fluorine atoms on the surface quantitatively. In addition, the physical properties of UVWCAC UV-cured films, such as gel content, water absorption, pencil hardness, adhesion, chemical resistance, mechanical properties, optical transmittance and thermal properties were also investigated in detail. The novel UVWCAC prepared via conventional radical polymerization not only had excellent properties but also had the prominent potential application in large scale industrialization.
Co-reporter:Jianquan Tan, Weiqu Liu, Zhengfang Wang
Journal of Fluorine Chemistry 2016 Volume 189() pp:79-87
Publication Date(Web):September 2016
DOI:10.1016/j.jfluchem.2016.08.001
•Novel amphiphilic graft copolymers containing long fluorinated side chains was synthesized and characterized.•Amphiphilic graft comopolymer performed significant pH-sensitivity.•The chain length, as well as the amount of fluorinated macromonomer had significant influence of the CMC and particle size.•Polymeric micelles performed spherical shape.•Amphiphilic graft comopolymer showed extremely low cytotoxicity.Novel amphiphilic graft copolymers containing 4,4,4,3,3,2-hexafluorobutyl side chains were designed and synthesized via radical polymerizaion of acrylic acid (AA), poly (ethylene glycol) methyl ether methacrylate (PEGMA) and homemade fluorinated macromonomer (PHFBMA-GMA) and the physicochemical properties of polymeric micelles prepared therefrom were investigated. GPC, FTIR and 1H NMR were employed to characterize the structures of the copolymers. Potentiometric titration measurement confirmed that the pH-sensitive segments were successfully incorporated and the copolymer performed pKa similar to the reported values. A series of random copolymers with the same chemical composition were employed to make comparisons with the graft copolymers. The critical micelle concentrations (CMC) of the copolymers at different pH (5.0 and 9.0) were determined by fluorescence spectroscopy and surface tension measurements. CMC values showed a high degree of consistency between these two methods. The results showed that CMC values for random copolymers were one magnitude order higher than that of graft copolymers. Graft copolymers performed lower CMC larger particle size compared to random copolymers. No significant difference was observed among graft or random copolymers. CMC values and particle size increased while zeta potential values showed significant decrement with increasing pH, indicating significant pH-sensitivity of the copolymers. With regard to the influence of the amount and the molecular weight of PHFBMA-GMA on the properties, increasing the amount and molecular weight of PHFBMA-GMA was prone to lower CMC, larger particle size while zeta potential performed no significant change. Transmission electron microscopy (TEM) showed that the morphological shapes of the copolymers performed spherical micelles. The cytotoxicity test showed that the comb-shaped copolymers performed extremely low cytotoxicity.The pH-sensitive self-assembled amphiphilic graft copolymers containing 4,4,4,3,3,2-hexafluorobutyl side chains could be potential candidates for nanotanks, hydrophobic drug carriers or surfactants and their facile preparation might fit for large scale industrialization.Schematic representation of the pH-sensitive micellization of the amphiphilic graft copolymer.
Co-reporter:Jianquan Tan;Honglei Wang;Yang Sun;Shijian Wang
Journal of Applied Polymer Science 2016 Volume 133( Issue 10) pp:
Publication Date(Web):
DOI:10.1002/app.43116
ABSTRACT
A novel macromonomer containing fluorinated units (PHFBMA-GMA) was synthesized through a two-step procedure: firstly, hexafluoro-butyl methacrylate (HFBMA) was polymerized in the presence of functional chain transfer agent 3-mercaptopropionic acid (MPA) and then the carboxyl acid group terminated polymer was end-capped with glycidyl methacrylate (GMA). Chemical structures of PHFBMA-GMA were characterized by gel permeation chromatography, fourier transform infrared spectroscopy (FTIR), and 1H nuclear magnetic resonance (NMR). Subsequently, PHFBMA-GMA was employed as reactive surface additives added into UV-cured polyacrylate to modify UV-curable coatings. It is convenient to control the tail length of the fluorinated segments in this study by adjusting the ratio of initiator and chain transfer agent. The influence of both the concentration and the molecular weight of PHFBMA-GMA on the surface properties of UV-cured films was investigated. With increasing both the concentration and the molecular weight of PHFBMA-GMA, the surface energy of the UV-cured films decreased. X-ray photoelectron spectroscopy was employed to characterize and quantify the surface composition and the results confirm the enrichment of fluorinate atoms on the surface. Moreover, the physical properties of UV-cured films, such as gel content, water absorption, pencil hardness, adhesion, chemical resistance, mechanical properties, optical transmittance, and thermal properties, were also investigated in detail. The novel macromonomer was economical but effective to modify the properties of the UV-curable coatings. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43116.
Co-reporter:Yanjuan Guo
Polymer Science, Series B 2016 Volume 58( Issue 3) pp:313-320
Publication Date(Web):2016 May
DOI:10.1134/S1560090416030064
A series of fluorinated diblock copolymers poly(2,2,3,4,4,4-hexafluorobutyl methacrylate)-b-poly(glycidyl methacrylate) PHFMA-b-PGMA with different fluorine content were synthesized by activator generated by electron transfer atom transfer radical polymerization (AGET ATRP). FTIR, 1H NMR and GPC data verified feasibility and controllability of the synthesis. In order to evaluate the effect of chain structure on the surface properties, corresponding homopolymer poly(2,2,3,4,4,4-hexafluorobutyl methacrylate) and random copolymer copoly(2,2,3,4,4,4-hexafluorobutyl methacrylate-r-glycidyl methacrylate) were also comparatively studied. Contact angle measurements indicated that the water and ethyleneglycol contact angles of block- and random copolymers increased with increase of fluorine content, but in different manner. This difference comes from different surface energy at the same fluorine content on film surface. The surface stability of block-copolymer was obviously better than that of random copolymer; the same results were observed in heat resistance tests.
Co-reporter:Honglei Wang, Weiqu Liu, Zhenlong Yan, Jianquan Tan and Guolun Xia-Hou
RSC Advances 2015 vol. 5(Issue 100) pp:81838-81846
Publication Date(Web):11 Sep 2015
DOI:10.1039/C5RA17240C
A series of novel methacrylate terminated polysiloxane hybrid oligomers and functional acrylate oligomers were synthesized and characterized by GPC, FT-IR and NMR. The functional polysiloxane oligomers were introduced into the acrylate UV-curing system to improve its surface and thermal properties. With increasing the organosiloxane content, the contact angles of the UV-cured films increased, suggesting that the organosiloxane segments migrated to the top surface. The SEM and EDS results demonstrated the migration of the organosiloxane segments. The refractive index results showed that the optical performance did not decrease after the organosiloxane segments were incorporated. According the TGA curves, the decomposition temperatures of the polysiloxane/acrylate composite UV-cured films were higher than that of the pure acrylate UV-cured film, which demonstrated that the organosiloxane groups enhanced the thermal properties of the acrylate film due to the high energy of the Si–C bond. The observation of the fractured-surface morphology showed that the organosiloxane segments floated on the surface of the UV-cured films.
Co-reporter:Jianquan Tan;Honglei Wang;Yang Sun
Journal of Polymer Research 2015 Volume 22( Issue 12) pp:
Publication Date(Web):2015 December
DOI:10.1007/s10965-015-0877-1
A novel acrylic comb-shaped copolymer containing long fluorinated side chains (ACCLF) was successfully synthesized by conventional radical polymerization of a novel mono-methacryloyloxy terminated fluorinated macromonomer (PHFBMA-MA), methyl methacrylate (MMA), isobutyl acrylate (IBA), and γ-methacryl propyl trimethoxyl silane (MPTS). GPC, FTIR, and 1H-NMR data successfully verified the synthesis. The influence of both the molecular weight and concentration of PHFBMA-MA on the surface properties of ACCLF films was investigated. By increasing both the concentration and the molecular weight of PHFBMA-MA, the surface energy of the films decreased and contact angle increased. The surface energy of ACCLF-1/3-8 with just 8 wt% PHFBMA-MA-1/3 (20.68 mN/m) was almost the same as that of the neat PHFBMA (20.36 mN/m), indicating the high efficiency of the macromonomer in lowering the surface energy of the comb-shaped copolymer. The surface composition of ACCLF was characterized and quantified by X-ray photoelectron spectroscopy (XPS). XPS results strongly confirmed that, at the same fluorinated content, long fluorinated chains modified film (9.36 % fluorine content for ACCLF-1/3-4 and 8.19 % fluorine content for ACCLF-1/6-4) showed higher fluorine concentration at the top surface than that of ACSF-4 modified film (1.52 %). ACCLF films also had excellent adhesion [on glass, tin plate, and polycarbonate (PC)], pencil hardness, and thermal properties. The novel ACCLF prepared via conventional radical polymerization not only had excellent comprehensive performance, but also has prominent potential application in large-scale industrialization.
Co-reporter:Zhenlong Yan, Weiqu Liu, Honglei Wang, Kui Su, Guolun Xia-Hou
Journal of Fluorine Chemistry 2014 Volume 157() pp:63-72
Publication Date(Web):January 2014
DOI:10.1016/j.jfluchem.2013.11.008
•Functional fluorinated oligomer was synthesized by the short perfluoralkyl monomer.•PDMS was used as spacer introduced between epoxy resin and fluorinated segments.•Kite-like fluorosilicone copolymer was prepared by fluorinated oligomer and PDMS.•High hydrophobic surface was obtained by incorporation fluorosilicone copolymer.•The surface fluorine content of modified resin was 2.18 × 105 time than bulk content.Two series of fluorinated siloxane star-like copolymers, with different molecular weight of siloxane segments and large fluorinated segments at the tail, were synthesized from dicarboxyl terminated poly(2,2,3,4,4,4-hexafluorobutyl acrylate) (CTHFA) and dihydroxypropyl-terminated poly(dimethyl siloxane) (PDMS). The chemical structures of the star-like copolymer (CTHFA-PDMS) were measured by FT-IR, 1H NMR, 13C NMR and GPC. Long siloxane spacers were employed to increase the migration efficiency of the large fluorinated segments. The long siloxane spacers also played a part in toughening the epoxy resin. Then, the copolymers reacted with 4′4-diphenylmethane dissocyanate and were used as a surface modifier of cured commercial diglycidyl ether of bisphenol A (DGEBA) at different concentration (0.1–0.5 wt% with respect to DGEBA). For both kinds of the CTHFA-PDMS modified DGEBA, high water contact angles (122° and 110°) were obtained at very low concentration (0.2 wt%). The surface chemical composition was measured by X-ray photoelectron spectroscopy (XPS). It was found that the fluorine and silicon atoms selectively migrated toward the outermost surface of modified DGEBA resin. The surface enrichment factors of fluorine and silicon atoms (SmF and SmSi) of modified resin were up to 2.18 × 105 and 2.93 × 104 times than the theoretical value expected for the bulk formulations at very low concentration (0.2 wt%). Moreover, the surface of modified epoxy resins showed good chemical stability by immersing in acidic and salt solutions. Scanning electron microscopy (SEM) images observed many ridges and rough crack structures of the fracture surface of modified DGEBA resin, indicating the CTHFA-PDMS toughened the DGEBA network.In order to lower the surface energy of epoxy resin with small amount of fluorine content, long siloxane spacers were introduced between graft copolymer and fluorinated segments. A novel fluorinated siloxane graft copolymer with different molecular weight of siloxane segments, carrying long fluorinated segments at the tail synthesized from dicarboxyl terminated poly(2,2,3,4,4,4-hexafluorobutyl acrylate) (CTHFA) and dihydroxypropyl-terminated poly(dimethyl siloxane) (PDMS). Then the fluorinated siloxane graft copolymer was employed as a surface modifier of cured commercial diglycidyl ether of bisphenol A (DGEBA) at different concentration (0.1–0.5 wt% with respect to DGEBA). For both kinds of fluorinated siloxane graft copolymer modified DGEBA, high water contact angle (122° and 110°) were obtained at very low concentration (0.2 wt%). The surface chemical composition was measured by X-ray photoelectron spectroscopy (XPS). The surface enrichment factors of fluorine and silicon atoms (SmF and SmSi) of modified resin were up to 2.18 × 105 and 2.93 × 104 times than the theoretical value expected for the bulk formulations at very low concentration (0.2 wt%). The tensile strength of modified DGEBA using CTHFA-g-PDMS with high molecular weight increased to a maximum value (82.2 MPa) with increasing CTHFA-g-PDMS content scanning electron microscopy (SEM) images observed many ridges and rough crack structures of the fracture surface of graft-modified DGEBA resin, indicating the CTHFA-g-PDMS toughened the DGEBA network.
Co-reporter:Zhenlong Yan, Weiqu Liu, Nan Gao, Honglei Wang, Kui Su
Applied Surface Science 2013 Volume 284() pp:683-691
Publication Date(Web):1 November 2013
DOI:10.1016/j.apsusc.2013.07.156
Highlights
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A novel vinyl-terminated fluorosilicone graft copolymer was synthesized (Vi-PFSi).
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High hydrophobic and oleophobic surface was obtained using small amount of Vi-PFSi.
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Morphology analysis revealed that fluorosilicone groups migrated toward surface.
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Fluorosilicone groups obviously improved the dielectric and electric properties.
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Tribological property of cured film was enhanced because of fluorosilicone groups.
Co-reporter:Nan Gao, WeiQu Liu, ZhenLong Yan, ZhengFang Wang
Optical Materials 2013 Volume 35(Issue 3) pp:567-575
Publication Date(Web):January 2013
DOI:10.1016/j.optmat.2012.10.023
Cycloaliphatic epoxy–silicone resins were successfully synthesized through a two-step reaction route: (і) hydrosilylation of 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) and 1,2-epoxy-4-vinyl-cyclohexane (VCMX), (іі) blocking of unreacted SiH in (і) with n-butanol. The molecular structures of the cycloaliphatic epoxy–silicone resins were characterized by Fourier transform infrared (FT-IR) and nuclear magnetic resonance (1H NMR and 29Si NMR). High grafting efficiencies of epoxy groups were confirmed by 1H NMR combined with weighting results, indicating over 90 mol% of cycloaliphatic epoxy were grafted on the silicone resins. Subsequently, SiH groups from TMCTS were almost totally consumed after the blocking reactions. In comparison with commercial available cycloaliphatic epoxy resin 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ERL-4221) cured by MHHPA, the cured cycloaliphatic epoxy–silicone resins exhibited better thermal stability, lower water absorption and higher UV/thermal resistance. Moreover, the characteristics of transmittance (>90%, 800 nm), 5 wt.% mass loss temperature (>330 °C) and no yellowing during thermal aging at 120 °C or UV aging for 288 h of the cured cycloaliphatic epoxy–silicone resins, made them possible for power light-emitting diode (LED) encapsulants, or other packaging materials, like optical lenses, and electronic sealings.Highlights► Cycloaliphatic epoxy–silicone resins were prepared by a two-step reaction. ► The synthesized resins exhibited good compatibility and high transparent. ► Properties of cured resins with different epoxy values were studied. ► Excellent UV resistance and thermal stability of the cured resins. ► Potential application of the cured resins in LED packaging.
Co-reporter:Zhenlong Yan, Weiqu Liu, Nan Gao, Ziqi Ma, Minjian Han
Journal of Fluorine Chemistry 2013 Volume 147() pp:49-55
Publication Date(Web):March 2013
DOI:10.1016/j.jfluchem.2013.01.014
A novel dimethacrylate terminated, poly(2,2,3,4,4,4-hexafluorobutyl acrylate (MATHFA), was synthesized in four-step procedure, and the structures were characterized by FT-IR and 1H NMR spectra. The fluorinated acrylic oligomer was employed as reactive surface additives and copolymerized with bisphenol-A epoxy methacrylate (EMA) in UV-curable formulation to improve the surface properties of UV-cured films. The influence of MATHFA concentration and length, i.e. the number of repeat units on the bulk and surface properties of the films were investigated. Contact angle measurements showed that the high hydrophobic surfaces on the air side of films were obtained by the introduction of fluorinated oligomers in very low amount (less than 1.3 wt.%) in the UV-curable mixed formulation, while the glass side did not changed. The surface composition and the surface enrichment factors measured by X-ray photoelectron spectroscopy (XPS) confirmed the selective enrichment of fluorinated moieties at the outermost surface of cured films and also proved the longer MATHFA was easier to concentrate on the air side than that of shorter MATHFA.Graphical abstractA novel difunctional fluorinated acrylic oligomer, poly(2,2,3,4,4,4-hexafluorobutyl acrylate (MATHFA), was successfully synthesized and employed as reactive surface additives in bisphenol-A epoxy methacrylate UV-curable formulation to improve the surface properties of UV-cured films. The influence of MATHFA concentration and the length of fluorinated chain, i.e. the number of repeat units on the bulk and surface properties of the films were investigated. Contact angle measurements showed that the high hydrophobic surfaces on the air side of films were obtained by the introduction of fluorinated oligomers in very low amount (less than 1.3 wt.%) in the UV-curable mixed formulation. The surface composition and the surface enrichment factors measured by X-ray photoelectron spectroscopy (XPS) confirmed the selective enrichment of fluorinated moieties at the outermost surface of cured films and also proved the longer fluorinated chain was easier to concentrate on the air side than that of shorter fluorinated chain.Highlights► A novel difunctional fluorinated oligomer (MATHFA) was successfully prepared. ► The film containing 1.3 wt.% of MATHFA exhibits very high hydrophobic surfaces. ► XPS confirmed that longer fluorinated chain was easier migration to the air-side. ► The modified films can maintain the bulk properties due to low amount of MATHFA.
Co-reporter:Yue Sun;Ziqi Ma
Polymer Bulletin 2013 Volume 70( Issue 5) pp:1531-1542
Publication Date(Web):2013 May
DOI:10.1007/s00289-013-0908-1
A novel fluoropolymer of epoxy-terminated poly(2,2,3,4,4,4-hexafluorobutyl methacrylate) (E-PHFMA) was synthesized and incorporated into epoxy resin to prepare thermosets. Gel permeation chromatography and 1H nuclear magnetic resonance data obtained verified the synthesis and measured the structure of the polymer. In order to demonstrate the effect of epoxy group on the properties of the thermosets, the corresponding fluoropolymer without epoxy group was prepared and the properties of thermosets modified by two kinds of fluoropolymers were comparatively studied. The contact angle measurements indicated that the thermosets modified with E-PHFMA had a little worse hydrophobicity but better surface stability. Scanning electron microscopy revealed the surface morphologies of the modified thermosets before or after surface stability experiment. The results of differential scanning calorimetry and thermogravimetric analysis showed that the thermosets modified with E-PHFMA had higher thermal stability.
Co-reporter:Chunyi Tang
Journal of Applied Polymer Science 2012 Volume 123( Issue 3) pp:1724-1731
Publication Date(Web):
DOI:10.1002/app.34637
Abstract
Cationic UV-curable methacrylate copolymers consisting of glycidyl methacrylate, iso-butyl methacrylate, and 2,2,3,4,4,4-hexafluorobutyl methacrylate were synthesized, and their structures were characterized by FTIR, 1H NMR, and 13C NMR. A series of UV-cured composite films based on the synthesized copolymers and an alicyclic epoxy resin, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (CE) were obtained through photopolymerization. Their surface contact angle, chemical ability, gloss, light transmittance, thermal behavior, micromorphology, and shrinkage were investigated. Results indicated that these cured resins showed excellent gloss and visible light transmittance; after the combination of the copolymers and CE, and in the presence of fluorine in the curing systems they exhibited relatively fine water resistance, chemical, and thermal stability. It was observed that these copolymers could decrease the degree of the volume shrinkage to CE. The UV-curable materials may have promising applications in optical fiber coatings, flip chip and Organic Light-Emitting Diode (OLED) packing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Co-reporter:Zhenlong Yan;Nan Gao;Yue Sun;Haisheng Chen
Iranian Polymer Journal 2012 Volume 21( Issue 10) pp:721-730
Publication Date(Web):2012 October
DOI:10.1007/s13726-012-0074-6
A novel dicarboxyl-terminated poly(2,2,3,4,4,4-hexafluorobutyl acrylate) oligomer (CTHFA) was synthesized through metal-free anionic polymerization and hydrolysis reaction. Chemical structures of CTHFA were characterized by gel permeation chromatography and 1H NMR. Two types of CTHFA with different chain lengths were initially used as an efficient surface modifier to improve the surface properties of epoxy resin, at the content of CTHFA ranging between 0 and 8 wt%. We minimized the amounts of the CTHFA used to achieve a high hydrophobic surface that was not obviously affected by the thermal properties of the epoxy resin. Surface properties and surface composition of the designed fluorinated epoxy resin were investigated by the contact angle and X-ray photoelectron spectroscopy (XPS). Modified epoxy resin with 5 wt% CTHFA containing longer chain length showed excellent hydrophobic surface properties (a high water contact angle about 115° and low surface energy 14.12 mN/m2) while the modified epoxy resin with 5 wt% CTHFA containing shorter chain length did not. XPS analyses indicated that the 5 wt% of fluorinated CTHFA epoxy resin with long macromolecular-chain enhanced more fluorinated groups’ migration to the surface than the fluorinated CTHFA-modified epoxy resin with short macromolecular-chain at the same content. Moreover, thermal properties of CTHFA-modified epoxy resin were also investigated.
Co-reporter:Nan Gao;SongQi Ma;Chunyi Tang;ZhenLong Yan
Journal of Polymer Research 2012 Volume 19( Issue 8) pp:
Publication Date(Web):2012 August
DOI:10.1007/s10965-012-9923-4
Oligo-fluorosiloxane (DFOS) and epoxy-containing oligo-fluorosiloxane (DFEHOS) were synthesized by the hydrolytic condensation reaction to modify 3, 4-epoxycyclohexylmethyl-3, 4-epoxycyclohexanecarboxylate (ERL-4221) for potential application in LED packaging. The chemical structures of DFOS and DFEHOS were characterized by Fourier transform infrared (FT-IR), 29Si nuclear magnetic resonance (29Si NMR), and gel permeation chromatography (GPC). The thermal behavior, mechanical properties, morphologies of impact fracture surfaces, surface wettability and absorbency of the modified epoxy resins were examined by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile and impact testing, scanning electron microscopy (SEM), and contact angle measurement, respectively. The experimental results indicated that the contact angles, surface energies and water absorption ratios of the modified epoxy resins were effectively improved by the introduction of oligo-fluorosiloxanes. Compared to neat epoxy resin, the thermal stabilities of DFEHOS-modified epoxy resins were basically kept, and that of DFOS-modified epoxy resins were slightly depressed with the increasing content of modifiers. As the additive quantity of modifiers was about 5pph to 15pph relative to ERL-4221, good thermal stability, fracture toughness and surface hydrophobicity of the modified epoxy resin was exhibited, and the cured DFEHOS-10 that embraced the relatively optimum comprehensive property was possible for LED encapsulation. Moreover, the reactable groups formed during hydrolytic condensation in DFOS and DFEHOS made good compatibilities between the modifiers and the epoxy matrix.
Co-reporter:Yue Sun
Journal of Polymer Research 2012 Volume 19( Issue 1) pp:
Publication Date(Web):2012 January
DOI:10.1007/s10965-011-9768-2
A series of novel cross-linkable copolymers 2, 2, 3, 4, 4, 4-hexafluorobutyl methacrylate-poly (isobutyl methacrylate)-b-poly[3-(trimethoxysilyl)propyl methacrylate] (HFMA-PIBMA-b-PTMSPMA) were synthesized via atom transfer radical polymerization (ATRP). The synthesis and structure of the polymers were characterized by gel permeation chromatography (GPC), Fourier transform infrartd (FTIR) and 1H nuclear magnetic resonance (NMR). The properties of HFMA-PIBMA-b-PTMSPMA and the corresponding copolymers end-capped with nonfluorinated acrylate were comparatively studied by contact angle, transmission electron micrograph (TEM), and dynamic light scattering (DLS) measurement. The results indicated that the surface properties and self-assembly behaviors of HFMA-PIBMA-b-PTMSPMA were changed greatly by the introducing of only one fluorinated acrylate. Finally, the transparent solid materials with a slightly blue color were obtained based on the cross-linked behaviors of HFMA-PIBMA-b-PTMSPMA and fracture surfaces of the materials were exhibited by scanning electron microscopy (SEM).
Co-reporter:Yue Sun
Polymer Bulletin 2012 Volume 68( Issue 1) pp:15-26
Publication Date(Web):2012 January
DOI:10.1007/s00289-011-0513-0
The bromo-terminated small-molecule initiator was prepared by the direct addition reaction of 2,2,3,4,4,4-hexafluorobutyl methacrylate (HFMA) or dodecafluoroheptyl methacrylate (DFMA) with hydrobromic acid in acetic acid under mild conditions. This greatly widened the initiators used for atom transfer radical polymerization (ATRP). The successful polymerization of isobutyl methacrylate (IBMA) or methyl methacrylate (MMA) derived from HFMA-Br or DFMA-Br indicated that fluorinated acrylates could be used as initiators for ATRP. The data of GPC showed the well controlling of the initiator system. FTIR and 1H NMR characterized the structures of the initiators and their polymers. Contact angle measurement indicated that although only one molecule of fluorinated acrylate was introduced, the surface properties of polymers were improved greatly.
Co-reporter:Yue Sun
Polymer Bulletin 2012 Volume 68( Issue 7) pp:1815-1829
Publication Date(Web):2012 April
DOI:10.1007/s00289-011-0652-3
The bromo-terminated macroinitiator was prepared by direct addition reaction of difunctional poly(dimethylsiloxane) (PDMS) containing methyl methacrylate end groups with hydrobromic acid in acetic acid under mild conditions, and well-defined triblock copolymers of poly(methyl methacrylate-b-dimethylsiloxane-b-methyl methacrylate) (MMA-b-DMS-b-MMA) were synthesized via activators generated by election transfer atom transfer radical polymerization (AGET ATRP). The gel permeation chromatography data obtained verified the polymerization and showed the well controlling of the reaction. FTIR and 1H NMR measured the structure of the macroinitiator and copolymers. The contact angle measurement indicated that the water contact angles decreased gradually with the increasing of PMMA block content. The self-assembly behaviors of the triblock polymer were studied by transmission electron micrograph, scanning electron microscopy, and dynamic light scattering measurement. The results indicated that the polymers could self-assemble into various complex morphologies in different solvents and the morphologies depended on the properties of solvents. The possible molecular packing models for self-assembly behaviors of the ABA triblock polymers were proposed.
Co-reporter:Yue Sun, Weiqu Liu
Journal of Fluorine Chemistry 2011 Volume 132(Issue 1) pp:9-14
Publication Date(Web):January 2011
DOI:10.1016/j.jfluchem.2010.10.004
A new fluorinated macroinitiator of poly 2,2,3,4,4,4-hexafluorobutyl methacrylate–Br (PHFMA–Br) was prepared via activator generated by electron transfer atom transfer radical polymerization (AGET ATRP), and then a series of fluorinated block copolymers with different fluorine content were successfully synthesized from the macroinitiator by the second step AGET ATRP. GPC, FTIR and 1H NMR data obtained verified the synthesis. Contact angle measurement indicated that proper fluorine content could decrease the surface energy and increase the contact angle of the copolymer films. XPS characterization showed that the large difference in surface energy between the block and random copolymer film resulted from the difference of the fluorine content on the surface, although the fluorine content of the two copolymers in bulk was similar. The self-assembly behavior of the fluorinated block copolymer in selective solvents was evaluated by the TEM study, and the stable micelles with a core–shell structure were observed when the copolymer content was about 1 wt%.Graphical abstractThe fluorinated macroinitiator of poly 2,2,3,4,4,4-hexafluorobutyl methacrylate–Br (PHFMA–Br) was firstly prepared via activator generated by electron transfer atom transfer radical polymerization (AGET ATRP), then its diblock copolymer of poly 2,2,3,4,4,4-hexafluorobutyl methacrylate-block-poly(iso-butyl methacrylate) (PHFMA-b-PiBMA) was successfully synthesized using the fluorinated macroinitiator by a second step AGET ATRP.Research highlights▶ The initiator of poly 2,2,3,4,4,4-hexafluorobutyl methacrylate–Br was prepared. ▶ A series of block copolymers was synthesized from the initiator via AGET ATRP. ▶ The structures of the initiator and its diblock polymers were verified. ▶ The properties of the diblock copolymers were also studied.
Co-reporter:Zhengfang Wang;Chaohui Hu;Songqi Ma
Journal of Applied Polymer Science 2011 Volume 121( Issue 4) pp:2213-2219
Publication Date(Web):
DOI:10.1002/app.33824
Abstract
A novel phosphorus- and silica-containing hybrid (DPS) was synthesized by the reaction between diethyl phosphate (DEP) and polyhedral oligomeric siloxanes (POS) formed by hydrolysis condensation of 3-glycidoxypropyltrimethoxysilane (GPTMS). The novel phosphorus- and silica-containing hybrid was characterized by the flourier transform infrared spectroscope (FT-IR), silicon nuclear magnetic resonance, and gel permeation chromatography (GPC). Then, the determination of the activation of the reaction between epoxy resin and phosphorus-, and silica-containing hybrids was studied by differential scanning calorimeter (DSC). In the presence of catalyst, the activation energies of the curing reaction were 63.3 and 66.7 kJ/mol calculated by Kissinger model and Ozawa model respectively. The thermal and flame retardant properties of the cured epoxy modified by DPS were determined by differential scanning calorimeter (DSC), thermal gravimetric analysis (TGA), and limited oxygen index (LOI). The results revealed that those properties were improved in comparison with unmodified epoxy resin. In addition, scanning electron microscopy (SEM) was used to investigate the morphology of the cured epoxy resin modified by DPS. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Co-reporter:Songqi Ma;Nan Gao;Zhenlong Yan;Yuan Zhao
Macromolecular Research 2011 Volume 19( Issue 9) pp:
Publication Date(Web):2011 September
DOI:10.1007/s13233-011-0911-z
A novel polysiloxane (GxDy) containing a large number of epoxide groups and flexible segments was synthesized by hydrolysis and condensation of 3-glycidoxypropyl trimethoxysilane (GPTMS) and dimethyldiethoxylsilane (DMDES) to toughen the 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ERL-4221). The chemical structures of GxDy (molar ratio of GPTMS to DMDES is x/y) were confirmed by Fourier transform infrared spectroscopy (FTIR), 29Si nuclear magnetic resonance spectroscopy (NMR), and gel permeation chromatography (GPC), and G4D6 have the highest degree of branching. The thermal and mechanical properties, morphologies and transmittance of the cured epoxy resins were examined by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile testing, fracture testing, SEM, and UV-vis spectroscopy. The Tg of the GxDy modified epoxy depends on the structure and addition content of GxDy. The TGA results under a N2 demonstrate that the thermal stability of the epoxy resin was improved by GxDy and the Si-(O-)3 from the GPTMS part forms silica more easily than the Si-(O-)2 from the DMDES part. The addition of 10 phr G4D6 resulted in greatly improved toughness, but maintained the transmittance of the epoxy resin. In addition the morphology of the fracture surfaces showed that GxDy can be dispersed homogeneously in the epoxy resin, and the toughening follows the pinning and crack tip bifurcation mechanism. In conclusion, GxDy can increase the toughness and thermal properties of the ERL-4221 system simultaneously, and maintain its transmittance. Therefore, GxDy can be used as a toughening agent for light emitting diode (LED)-packaging epoxy resins.
Co-reporter:Chunyi Tang, Weiqu Liu, Songqi Ma, Zhengfang Wang, Chaohui Hu
Progress in Organic Coatings 2010 Volume 69(Issue 4) pp:359-365
Publication Date(Web):December 2010
DOI:10.1016/j.porgcoat.2010.07.009
Co-reporter:Chunyi Tang
Journal of Applied Polymer Science 2010 Volume 117( Issue 3) pp:1859-1866
Publication Date(Web):
DOI:10.1002/app.32164
Abstract
Photosensitive organofluorine and organosilicon play a key role in improving the properties of UV-curing coating materials. In this study, by using 2,2,3,4,4,4-hexafluorobutyl methacrylate (HFMA) and a synthesized side methacryloxy group polysiloxane (MAPS) as modifying materials and bisphenol-A epoxy methacrylate (BEMA) as matrix, respectively, a innovative UV-curing system, BEMA/HFMA/MAPS composite system was developed. Through UV-cure process, a series of BEMA/HFMA, BEMA/MAPS, and BEMA/HFMA/MAPS cured composite films with different proportions were successfully obtained. It was found that HFMA monomer was helpful for the reduction of the surface energy of the UV-cured composite films and the enhancement of their water resistance property. Without HFMA in BEMA matrix, MAPS could facilitate the improvement of the properties of BEMA/MAPS cured films, and the presence of MAPS in BEMA/HFMA/MAPS system could significantly decrease the surface energy of the cured films to 22.1 mJ/m2 and improve their thermal stabilities and water resistance properties by measurements, contact angle, TGA, DSC, and water resistance. To the SEM observation, HFMA and MAPS were well distributed in the cured films in favor of their excellent performances. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Dan Yu;Yunfeng Liu
Polymer Composites 2010 Volume 31( Issue 2) pp:334-339
Publication Date(Web):
DOI:10.1002/pc.20809
Abstract
A novel epoxy resin modifier, phosphorus-containing epoxide siloxane (DPS) with cyclic phosphorus groups in the SiO network, was prepared from the reaction of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) with polyhedral-oligomeric siloxanes, which was synthesized by the sol–gel reaction of 3-glycidoxypropyltrimethoxysilane. DPS was confirmed by Fourier transform infrared and 29Si NMR measurement, and then was employed to modify epoxy resin at various ratios, with 4,4-diaminodiphenyl-methane as a curing agent. In order to make a comparison, DOPO-containing epoxy resins were also cured under the same conditions. The resulting organic–inorganic hybrid epoxy resins modified with DPS exhibited a high glass transition temperature (Tg), a good thermal stability, and a high limited oxygen index. In addition, the tensile strength of cured products was also rather desirable. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Co-reporter:Chunyi Tang
Journal of Coatings Technology and Research 2010 Volume 7( Issue 5) pp:651-658
Publication Date(Web):2010 September
DOI:10.1007/s11998-010-9247-4
Two UV-curable polysiloxanes—side methacryloxy group polysiloxanes (MAPS) —were successfully synthesized through a two-step reaction. Two series of various percentages of these synthesized MAPS were then cured with bisphenol-A epoxy methacrylate (BEMA) via UV radiation to obtain cured coatings. We found that the additive MAPS improved the thermal stability of the cured coatings. It not only reduced the surface energy of the coatings, but also significantly affected the other properties, including gloss, flexibility, and water resistance. Compared to the phase separation between BEMA and MAPS-1 with lower volume of methacryloxy groups, MAPS-2 with higher volume of methacryloxy groups dispersed uniformly in BEMA, thereby provding good performances for such coating materials.
Co-reporter:Weiqu Liu;Songqi Ma;Zhengfang Wang;Chaohui Hu;Chunyi Tang
Macromolecular Research 2010 Volume 18( Issue 9) pp:853-861
Publication Date(Web):2010 September
DOI:10.1007/s13233-010-0912-3
A novel highly epoxidized polysiloxane was synthesized to modify the diglycidyl ether of bisphenol-A (DGEBA). The mechanical and thermal properties as well as the morphology of the cured epoxy resins were examined by tensile testing, impact testing, fracture testing, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and environmental scanning electron microscopy (ESEM). The chemical structure of the highly epoxidized polysiloxane (HEPSO) was confirmed by Fourier transform infrared spectroscopy (FTIR), 29Si nuclear magnetic resonance spectroscopy (29Si NMR), and gel permeation chromatography (GPC). The Tg increased by approximately 8 °C after introducing HEPSO. TGA in air showed that the initial degradation temperature for 5% weight loss (Td 5%), the temperature for 50% weight loss (Td 50%) and the residual weight percent at 800 °C (R800) were increased after introducing HEPSO. The addition of 4 phr HEPSO2 resulted in the highest increase in tensile strength, impact strength and fracture toughness (KIC). The morphology of the fracture surfaces show that the miscibility of polysiloxane with epoxy resin increased with increasing epoxide group in HEPSO. The high epoxide groups in HEPSO can react during the curing process, and participate chemically in the crosslinking network. HEPSO is expected to improve significantly the toughness and thermal stability of epoxy resin.
Co-reporter:Songqi Ma;Dan Yu;ZhengFang Wang
Macromolecular Research 2010 Volume 18( Issue 1) pp:22-28
Publication Date(Web):2010 January
DOI:10.1007/s13233-009-0053-8
Polyether-grafted-polysiloxane (FPMS) and epoxy-miscible polysiloxane particles (EMPP) were prepared to improve the toughness of epoxy resin. The chemical structures of the products were characterized by FTIR, 1H NMR, 29Si NMR, and gel permeation chromatography (GPC). The morphology of the EMPP was analyzed by transmission electron microscopy (TEM). The thermal and mechanical properties and morphologies of the polysiloxanes modified epoxy networks were examined by differential scanning calorimetry (DSC), tensile and impact testing, and scanning electron microscopy (SEM). Microspheres were observed in the EMPP modified epoxy network, whereas irregular particles were obtained for the FPMS modified epoxy resin. The FPMS and EMPP effectively improved the tensile and impact strength of the cured epoxies, while the glass transition temperatures (Tgs) were depressed slightly. Moreover, with the same content of modifiers, the EMPP-modified epoxy network exhibited higher impact strength and lower Tgs than the FPMS-modified epoxy network.
Co-reporter:Songqi Ma;Chaohui Hu;Zhengfang Wang;Chunyi Tang
Macromolecular Research 2010 Volume 18( Issue 4) pp:392-398
Publication Date(Web):2010 April
DOI:10.1007/s13233-010-0408-1
Dendritic polymers have attracted increasing attention in the field of epoxy resin toughening. This paper is the first report of the use of a novel dendritic polysiloxane (DPSO) bearing high epoxide groups to modify the diglycidyl ether of bisphenol-A (DGEBA). The thermal properties, toughness and morphology of the cured epoxy resins were examined by DSC, TGA, impact testing and SEM. The chemical structure of DPSO was confirmed by FTIR, 29Si NMR and GPC. The Tg increased by approximately 7 °C after introducing the DPSO. The TGA results under N2 and air atmospheres showed that the initial degradation temperature for 5% weight loss (Td 5%), temperature for 50% weight loss (Td 50%) and residual weight percent at 800 °C (R800) all increased after introducing DPSO. Moreover, the addition of 3 phr DPSO100 resulted in a 70.4% increase in impact strength compared to that of the neat epoxy. The morphology of the fracture surfaces shows that the miscibility of polysiloxane with epoxy resin increased with increasing number of epoxy groups in DPSO, and the improved toughness was attributed to the rubber-bridged effect. The high number of epoxy groups in dendritic polysiloxane can react during the curing process, and participate chemically in the crosslinking network. DPSO is expected to improve significantly the toughness and thermal stability of epoxy resin.
Co-reporter:Shouping Xu, Weiqu Liu
Journal of Fluorine Chemistry 2008 Volume 129(Issue 2) pp:125-130
Publication Date(Web):February 2008
DOI:10.1016/j.jfluchem.2007.09.008
The hydrophobic monomer dodecafluoroheptyl methacrylate has been copolymerized with hydrophilic monomer methacrylic acid in aqueous solution without any additional emulsifier used via a two-step polymerization process of RAFT. The FTIR and GPC results indicated that amphiphilic copolymers with a narrow molecular weight distribution and well-defined blocks have been synthesized successfully. And the copolymers are likely to form steady micelles in the emulsion. Indicated by TEM, it is clear that micelles with a diameter of 70–120 nm have been formed. Despite a content of 22 wt% of hydrophilic carboxyl, films formed by casting the emulsion onto the baseplate can be hydrophobic after heating treatment.Well-defined amphiphilic fluorinated copolymers have been copolymerized directly in emulsifier-free aqueous solution via RAFT. And it was found these copolymers can form stable micelles in the emulsion. Besides, when coated on baseplate, the copolymers will form hydrophilic films, and after a heating treatment, the film can became relatively hydrophobic.
Co-reporter:Shouping Xu
Journal of Polymer Science Part B: Polymer Physics 2008 Volume 46( Issue 11) pp:1000-1006
Publication Date(Web):
DOI:10.1002/polb.21432
Abstract
Amphiphilic fluorinated block copolymers synthesized via reversible addition-fragmentation chain transfer polymerization were used for the preparation of aggregates of various morphologies. First, dissolve the copolymer in 2-butanone; second, add a precipitant solvent, which was the mixture of water and methanol, to induce the aggregation of the hydrophobic fluorinated block. With a hydrophilic tail and a very hydrophobic segment, these copolymers are likely to self-assemble in solution and form aggregates. Observed by TEM, spheres, rods, and vesicles can be formed by changing the precipitant mixture contents. Besides, these aggregates were found to be able to carry hydrophobic fluorinated homopolymers, and two suggested processes have been proposed to explain their morphology changes from original spheres, rods and vesicles into larger size spheres. Finally, hollow bilayer spheres and tubules can be achieved after extracting homopolymers in the center of the newly formed spheres. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1000–1006, 2008
Co-reporter:Shouping Xu, Weiqu Liu
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2008 Volume 326(Issue 3) pp:210-213
Publication Date(Web):1 September 2008
DOI:10.1016/j.colsurfa.2008.05.029
Amphiphilic fluorinated block copolymers are prepared via the two-step reversible addition-fragmentation chain transfer polymerization (RAFT), and micelles with well-defined core–shell morphology can be observed in the soap-free aqueous emulsion by transmission electron microscopy (TEM). By adding a relatively excessive amount of initiator, free radical polymerization also happens, and a small amount of hydrophobic homopolymers are produced, which exist in the hydrophobic core. After extracting homopolymers in the core by adding a certain amount of benzotrifluoride into the diluted emulsion, drastic changes in the morphology and stability of fluorinated block copolymers aggregate were observed. First, cross-link and aggregating of the micelles was observed; second, by stirring for a further 50 min, hollow nanotubes can be produced.
Co-reporter:Yan-Bin Liu, Wei-Qu Liu, Meng-Hua Hou
Polymer Degradation and Stability 2007 Volume 92(Issue 8) pp:1565-1571
Publication Date(Web):August 2007
DOI:10.1016/j.polymdegradstab.2007.05.003
Different metal dicarboxylates such as calcium glutarate, zinc glutarate, calcium sebacate and zinc sebacate were investigated in this paper as thermal stabilizers (without and with calcium stearate and pentaerythritol as costabilizers) of poly(vinyl chloride) (PVC). The thermal stability of the PVC films was determined by two different methods which are visual color comparison and measurement of HCl release from heated pellets. Both zinc dicarboxylates and calcium dicarboxylates exhibited good thermal stability. With respect to stabilizing performance, zinc glutarate (ZnGa) was more effective than zinc sebacate (ZnSe), particularly in the presence of a large amount of pentaerythritol. Similarly, calcium glutarate (CaGa) was more effective than calcium sebacate (CaSe). And the relative order of stabilizing effectiveness of metal dicarboxylates was as follows: CaGa > CaSe > ZnGa > ZnSe. Moreover, the Ca–Zn complex thermal stabilizer and the Pe–Zn complex thermal stabilizer were also studied. It was found that no more than 20% of the zinc compound exhibited better stabilizing performance.
Co-reporter:Menghua Hou, Weiqu Liu, Qianqian Su and Yunfeng Liu
Polymer Journal 2007 39(7) pp:696-702
Publication Date(Web):May 16, 2007
DOI:10.1295/polymj.PJ2006111
A novel epoxy resin modifier, phosphorus-containing epoxide siloxane (PES) with pendant epoxide and cyclic phosphorus groups on the side chain of the polysiloxane backbone, was synthesized by the ring-opening reaction of epoxy-siloxane with 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). PES was characterized by 1H NMR and FT-IR measurements, and then it was employed to modify an epoxy resin at various ratios via pre-reaction with 4, 4′-diaminodiphenyl-methane (DDM) as curing agent. In order to compare with the epoxy resins modified with PES, DOPO-containing epoxy resins also cured under the same conditions. The thermal, thermomechanical, and flame-retardant properties of all cured polymers were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), the limited oxygen index (LOI) and cone calorimetry. The results showed that the epoxy resins modified with PES exhibited much better thermal properties and flame retardancy than the DOPO-containing epoxy resins at the same phosphorus content and the neat epoxy resin.
Co-reporter:Jianquan Tan, Weiqu Liu, Zhengfang Wang
Progress in Organic Coatings (April 2017) Volume 105() pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.porgcoat.2017.01.018
•A novel comb-shaped fluorinated (meth)acrylate copolymer was synthesized and characterized.•Modified epoxy resins performed low surface energy with extremely low fluorine concentrations.•XPS results revealed the enrichment of fluorine atoms on the surface.•AFM results demonstrated that rougher surface was obtained using the comb-shaped fluorinated reactive modifier.•Hydrophobic epoxy resins showed excellent physical performance and have promising application in anti-fouling coatings.Novel comb-shaped fluorinated (meth)acrylate copolymer was synthesized and used as reactive modifier for epoxy resins. The chemical structure of the comb-shaped fluorinated reactive modifier (CFRM) was characterized by GPC, FTIR and 1HNMR. In addition, a random fluorinated reactive modifier (RFRM) which possessed the same chemical composition but random structure was developed as a contrast modifier. Thorough performances of the modified thermosets modified with these two modifiers were investigated. Surface energy, surface composition and surface morphology were investigated by means of contact angle test, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Compared to the CFRM with RFRM, epoxy thermosets modified with CFRM performed lower surface energy, higher fluorine atomic concentration at the surface and rougher surface morphology. The thermosets modified with CFRM possessed even lower surface energy (18.32 mN/m) than polytetrafluoroethylene (18.50 mN/m) with just adding 0.05 wt% fluorine component (DFHMA structural unit), indicating its high efficiency and effectivess in improvement of surface hydrophobicity. Tensile strength tests and glass transition determined by dynamic mechanical thermal analysis (DMTA) showed that both tensile strength and Tg decreased slightly by incorporation of the two reactive modifier since the sofer segments were incorporated. And thermosets modified with CFRM performed slightly lower Tg than that of RFRM. The influence of the reactive modifier on Shore D hardness and thermal stabilities was not significant due to the low concentrations. The incorporation of the CFRM was more advantageous to lowering water absorption while the optical transmittance deteriorated. The hydrophobic epoxy resins modified with comb-shaped fluorinated reactive modifier might have the potential application in anti-fouling coatings and other occasions requiring low surface energy.
