Co-reporter:Chenfeng Yi, Jingbo Zhao, Zhiyuan Zhang, and Junying Zhang
Industrial & Engineering Chemistry Research November 22, 2017 Volume 56(Issue 46) pp:13743-13743
Publication Date(Web):October 31, 2017
DOI:10.1021/acs.iecr.7b03416
A simple route is described to synthesize cross-linked polyamides (cPAs) with excellent mechanical properties at mild conditions through a Michael addition reaction coupled with bulk polycondensation. A Michael addition of methyl acrylate with 1,6-hexanediamine was conducted in a bulk state at a N–H/C═C molar ratio of 1:1 under normal pressure at 50 °C, and a hexanediamine-tetraester was prepared. Bulk polycondensation of the hexanediamine-tetraester with 1,6-hexanediamine and isophoronediamine was conducted at 170 °C for 1 h and then in tetrafluoroethylene mold under reduced pressure for another 8 h. A series of cPA films were prepared. The Michael addition and the polycondensation were monitored by Fourier transform infrared, 1H NMR, and electrospray ionization mass spectrometry spectra. The cPA films were characterized with differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, and a tensile test. These cPAs exhibited Tg ranging from 37 to 61 °C, tensile strength up to 71 MPa, and strain at break of about 11%.
Co-reporter:Xiaokai Yuan;Zhihui Sang;Jingbo Zhao;Zhiyuan Zhang
Journal of Polymer Research 2017 Volume 24( Issue 6) pp:88
Publication Date(Web):08 May 2017
DOI:10.1007/s10965-017-1249-9
This study describes a non-isocyanate route for synthesis of aliphatic thermoplastic polyurethane elastomers (TPUEs) with excellent mechanical properties. Melt transurethane co-polycondensation of bis(hydroxyethyl) hexanediurethane with different polycaprolactone-diols was conducted at 170 °C under a reduced pressure of 3 mmHg to prepare a series of TPUEs. The TPUEs were characterized by gel permeation chromatography, FT-IR, 1H–NMR, wide angle X-ray scattering, DSC, TGA, dynamic mechanical analysis, atomic force microscopy, SEM, and tensile analyses. The TPUEs exhibited Mn above 18,100 g/mol, Tg of −35 to −11 °C, Tm of up to 107 °C, initial decomposition temperature over 269 °C, tensile strength up to 32 MPa with a strain at break of 1119%, and resilience of 65% to 83%. TPUEs with good tensile strength and resilience were successfully prepared through a non-isocyanate route.
Co-reporter:Suqing Li, Zhihui Sang, Jingbo Zhao, Zhiyuan Zhang, Jue Cheng, Junying Zhang
European Polymer Journal 2016 Volume 84() pp:784-798
Publication Date(Web):November 2016
DOI:10.1016/j.eurpolymj.2016.08.007
•Crystallizable TPU elastomers were prepared through a non-isocyanate route.•They were prepared by polymerizing a linear diurethanediol with PTMGs.•They exhibit melting temperature up to 161 °C.•They show tensile strength up to 24 MPa and resilience from 59% to 98%.A simple non-isocyanate route synthesizing aliphatic thermoplastic polyurethane elastomers (TPUEs) with good thermal and mechanical properties is described. Melt transurethane co-polycondensation of a diurethanediol, i.e. bis(hydroxyethyl) hexanediurethane, with different poly(tetramethylene glycol)s was conducted, and a series of TPUEs were prepared. They were characterized by GPC, FT-IR, 1H NMR, wide-angle X-ray scattering, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, atomic force microscope, and tensile test. The TPUEs exhibited an Mn up to 40,000 g/mol, an Mw up to 90,800 g/mol, Tm from 125 °C to 161 °C, initial decomposition temperature at over 261 °C, tensile strength up to 24 MPa, elongation at break from 182% to 1476%, and resilience up to 98%. TPUEs with high Tm, good tensile strength, and high resilience were prepared through a non-isocyanate route.
Co-reporter:Suqing Li, Zhihui Sang, Jingbo Zhao, Zhiyuan Zhang, Junying Zhang, and Wantai Yang
Industrial & Engineering Chemistry Research 2016 Volume 55(Issue 7) pp:1902
Publication Date(Web):February 4, 2016
DOI:10.1021/acs.iecr.5b04083
A simple nonisocyanate route for synthesizing crystallizable and tough aliphatic thermoplastic polyureas (TPUreas) is described. Melt transurethane polycondensation of diethylene glycol bis(3-aminopropyl) ether with bis(hydroxyethyl) hexanediurethane and bis(hydroxyethyl) isophoronediurethane was conducted at 170 °C under a reduced pressure of 3 mmHg, and a series of TPUreas were prepared. The TPUreas were characterized by GPC, FT-IR, 1H NMR, 13C NMR, 2D 13C–1H HSQC NMR, DEPT-135 13C NMR, DSC, TGA, wide-angle X-ray scattering, atomic force microscopy, and tensile tests. The TPUreas exhibited an Mn up to 12 000 g/mol, an Mw up to 17 600 g/mol, Tg between 2.8 and 18.1 °C, Tm from 140.5 to 149.8 °C, initial decomposition temperature of over 278.4 °C, and tensile strength up to 37.81 MPa with elongation at break of 691.25%. TPUreas with high Tm, good tensile strength, and good toughness were prepared through a nonisocyanate route.
Co-reporter:Guoliang Wang;Xiaokai Yuan;Jingbo Zhao;Zhiyuan Zhang
Journal of Polymer Research 2016 Volume 23( Issue 1) pp:
Publication Date(Web):2016 January
DOI:10.1007/s10965-015-0893-1
Bis (4-hydroxybutyl) terephthalate (BHBT) was synthesized from the condensation of dimethyl terephthalate with excessive 1,4-butanediol. Transurethane polycondensation of 1,6-bis (hydroxyethyloxy carbonyl amino) hexane (BHCH) with BHBT at different BHCH/BHBT molar ratios was carried out at 170 °C under a reduced pressure of 3 mmHg for different time. A series of non-isocyanate thermoplastic polyurethanes (NI-TPUs) containing dibutylene terephthalate units were prepared. The NI-TPUs were characterized by gel permeation chromatography, FT-IR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide angle X-ray scattering, and tensile test. The NI-TPUs exhibited Mn above 14200, Mw above 19700, Tg between 25.1 and 35.1 °C, Tm from 123.8 °C to 141.1 °C, initial decomposition temperature over 251.7 °C, and tensile strength up to 37.89 MPa with a strain at break of 475.28 %. NI-TPUs with high Tm, good tensile strength and good toughness were prepared. Introduction of dibutylene terephthalate units improved the mechanical properties obviously. Some urea linkages were formed during transurethane polycondensation because of the back-biting side reaction the -HNCOOCH2CH2OH terminal groups.
Co-reporter:Yue Li;Su-qing Li 赵京波;Zhi-yuan Zhang
Chinese Journal of Polymer Science 2016 Volume 34( Issue 10) pp:1220-1233
Publication Date(Web):2016 October
DOI:10.1007/s10118-016-1839-8
A simple non-isocyanate route is developed for synthesizing crystallizable aliphatic thermoplastic poly(ester urethane) elastomers (TPEURs) with good thermal and mechanical properties. Three prepolymers of 1,6-bis(hydroxyethyloxycarbonylamino) hexane (BHCH), i.e. PrePBHCHs, were prepared through the self-transurethane polycondensation of BHCH. A poly(butylene adipate) prepolymer (PrePBA) with terminal HO― groups was prepared and used as a polyester glycol. A series of TPEURs were prepared by the co-polycondensation of the PrePBHCHs with PrePBA at 170 °C under a reduced pressure of 399 Pa. The TPEURs were characterized by gel permeation chromatography, FTIR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray diffraction, atomic force microscopy, and tensile test. The TPEURs exhibited Mn up to 23300 g/mol, Mw up to 51100 g/mol, Tg ranging from −33.8 °C to −3.1 °C, Tm from 94.3 °C to 111.9 °C, initial decomposition temperature over 274.7 °C, tensile strength up to 18.8 MPa with a strain at break of 450.0%, and resilience up to 77.5%. TPU elastomers with good crystallization and mechanical properties were obtained through a non-isocyanate route.
Co-reporter:Suqing Li, Jingbo Zhao, Zhiyuan Zhang, Junying Zhang and Wantai Yang
RSC Advances 2015 vol. 5(Issue 9) pp:6843-6852
Publication Date(Web):16 Dec 2014
DOI:10.1039/C4RA12195C
A simple non-isocyanate route for synthesizing aliphatic thermoplastic polyurethane-ureas (TPUUs) and thermoplastic polyureas (TPUreas) is presented. Melt transurethane polycondensation of isophorone diamine or diethylene glycol bis(3-aminopropyl) ether with bis(hydroxyethyl) hexanediurethane, bis(hydroxyethyl) isophoronediurethane or bis(hydroxyethyl) piperazinediurethane was conducted at 170 °C under a reduced pressure of 3 mmHg. A series of thermoplastic TPUUs and TPUreas were prepared, and were characterized by gel permeation chromatography, FT-IR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, and tensile testing. The TPUUs and TPUreas have an Mn up to 14900 g mol−1, an Mw up to 43700 g mol−1, Tg between −18.6 °C and 116.8 °C, and an initial decomposition temperature of over 222.3 °C. A flexible TPUU exhibits a melting temperature of 77.7 °C, a tensile strength of 6.46 MPa, and an elongation at break of 180.20%.
Co-reporter:Suqing Li, Jingbo Zhao, Zhiyuan Zhang, Junying Zhang, Wantai Yang
Polymer 2015 Volume 57() pp:164-172
Publication Date(Web):28 January 2015
DOI:10.1016/j.polymer.2014.12.009
Co-reporter:Yong Deng;Su-qing Li 赵京波
Chinese Journal of Polymer Science 2015 Volume 33( Issue 6) pp:880-889
Publication Date(Web):2015 June
DOI:10.1007/s10118-015-1638-7
A non-isocyanate route for synthesizing thermoplastic polyurethanes with excellent thermal and mechanical properties was described. Melt transurethane polycondensation of 1,6-bis(hydroxyethyloxy carbonyl amino)hexane with four poly(ethylene glycol)s (PEGs), i.e. PEG400, PEG600, PEG1000, or PEG1500, was conducted at different molar ratios. A series of thermoplastic poly(ether urethane)s (TPEUs) with long PEG sequences were prepared. The TPEUs were characterized via gel permeation chromatography, FTIR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray scattering, and tensile tests. The TPEUs exhibit Tg between 12.4 °C and −40.4 °C, Tm of up to 149.8 °C, and initial decomposition temperature over 239.4 °C. The tensile strength of the TPEUs reaches 38.39 MPa with a strain at break of 852.92%.
Co-reporter:Chen Guo Li;Su Qing Li;Jing Bo Zhao;Zhi Yuan Zhang;Jun Ying Zhang ;Wan Tai Yang
Polymer Engineering & Science 2015 Volume 55( Issue 4) pp:763-770
Publication Date(Web):
DOI:10.1002/pen.23944
This article presents a convenient method for synthesizing segmented poly(ether ester amide)s (PEEAs) by polycondensation and chain extension. A nylon-6 oligomer prepared from ε-caprolactam and ethanolamine through ring-opening polymerization was polymerized with adipic acid and diglycol to prepare PEEA prepolymers (PrePEEAs) with ether linkages and amide contents ranging from 20 to 60 mol%. Chain extension of the PrePEEAs was conducted at 200°C using 2,2′-(1,4-phenylene)-bis(2-oxazoline) and carbonyl biscaprolactamate as combination chain extenders. The chain-extended PEEAs (ExtPEEAs) were characterized by viscometry, gel permeation chromatography, FT-IR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide angle X-ray diffraction, and tensile testing. Results show that incorporation of nylon-6 segments yields semicrystalline ExtPEEAs and that introduction of ether linkages improves the flexibility of the resultant polymers. ExtPEEAs showed Tm from 107.6 to 137.3°C, good thermal stability with initial decomposition temperatures above 337.3°C, and tensile strengths of up to 27.4 MPa with strains at break ranging from 231.24 to 1052.52%. POLYM. ENG. SCI., 55:763–770, 2015. © 2014 Society of Plastics Engineers
Co-reporter:Yong Deng, Suqing Li, Jingbo Zhao, Zhiyuan Zhang, Junying Zhang and Wantai Yang
RSC Advances 2014 vol. 4(Issue 82) pp:43406-43414
Publication Date(Web):01 Sep 2014
DOI:10.1039/C4RA05880A
A simple non-isocyanate route synthesizing aliphatic thermoplastic poly(ether urethane)s (PEUs) with good thermal and mechanical properties is described. Melt transurethane polycondensation of 1,6-bis(hydroxyethyloxy carbonyl amino)hexane (BHCH) with two ethylene glycol oligomers, i.e. triethylene glycol (3EG) and tetraethylene glycol(4EG), was conducted, and high molecular weight PEUs were prepared. The PEUs were characterized by gel permeation chromatography, FT-IR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide angle X-ray scattering, and tensile tests. The PEUs exhibited Mn above 32000, Mw above 54300, Tg ranging from 11.2 °C to 28.2 °C, Tm from 103.7 °C to 150.6 °C, and initial decomposition temperature over 237.4 °C. A PEU prepared at a BHCH/4EG molar ratio of 5:1 exhibited the best mechanical properties with tensile strength of 32.82 MPa and strain at break of 151.82%. Some urea linkages were formed due to a back-biting side reaction in the transurethane polycondensation.
Co-reporter:Suqing Li, Jingbo Zhao, Zhiyuan Zhang, Junying Zhang and Wantai Yang
RSC Advances 2014 vol. 4(Issue 45) pp:23720-23729
Publication Date(Web):15 May 2014
DOI:10.1039/C4RA02325K
Two nylon-6 oligomers with polymerization degrees (DP or n) of 6.82 and 4.52 terminated with H2N- and HO-groups (H2N–PAn–OHs) were prepared from caprolactam with ethanolamine via ring-opening polymerization at different molar ratios, and transformed into HO-terminated nylon-6 oligomers (HO–PAn–OHs) through reaction with excess caprolactone. Melt polycondensation of the HO–PAn–OHs, with 1,6-bis(hydroxyethyloxy carbonyl amino)hexane (BHCH) and polyethylene glycols (PEGs), was performed at 170 °C under normal pressure and at 180 °C under reduced pressure of 3 mmHg at different periods. A series of novel aliphatic thermoplastic poly(ether amide urethane)s with different short nylon-6 and PEG segments (s-PEAUs) was prepared. The obtained s-PEAUs were characterized by gel permeation chromatography, FTIR, 1H-NMR, 2D 1H–1H COSY NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray scattering, and tensile tests. The s-PEAUs exhibited an Mn up to 18400, an Mw up to 48900, Tm between 145.94 °C and 177.86 °C, initial decomposition temperature of over 253.39 °C, and tensile strength up to 30.03 MPa with elongation at break of 286.8%. Some urea linkages were formed during transurethane polycondensation.
Co-reporter:Hong-ying Zhao 赵京波;Hao Li;Tong Zhao
Chinese Journal of Polymer Science 2014 Volume 32( Issue 2) pp:187-196
Publication Date(Web):2014 February
DOI:10.1007/s10118-014-1393-1
Two polyborosiloxanes (PBSis) with char yield up to 74.13% at 800 °C were synthesized by the direct polycondensation of boric acid with phenyltrimethoxysilane in diglyme. The PBSis were characterized by gel permeation chromatography, IR spectroscopy as well as 1H-, 29Si- and 11B-NMR. PBSi modified phenol-formaldehyde resins (PBSi/PFs) were prepared at different PBSi/PF mass ratios and were cured at 150 °C. The PBSi/PFs were characterized by IR spectroscopy, scanning electron microscopy, thermogravimetric analysis and tensile test. The results revealed that the cured PBSi/PFs had sea-island morphology and higher char yield than the common PF. PBSi/PF blend with PBSi/PF mass ratio of 0.4:1 had char yield up to 70.83% at 800 °C. The PBSi/PFs had tensile strength similar to PF. The ceramization of PBSi/PFs was also studied. The silicon boron oxycarbide (SiBOC) ceramics formed were characterized by IR spectroscopy and elemental analysis. This method provided a valuable way to prepare easily shapeable polymer blends as ceramic precursors.
Co-reporter:Tiao Yin;Hui Yun Sun;Jing Bo Zhao;Zhi Yuan Zhang;Wan Tai Yang
Polymer Engineering & Science 2014 Volume 54( Issue 4) pp:756-765
Publication Date(Web):
DOI:10.1002/pen.23612
This article provided a convenient method to synthesize aliphatic polyesteramides mainly composed of alternating diester diamide units by polycondensation and chain extension. Two kinds of polyesteramide prepolymers were prepared through melt polycondensation from N,N'-bis(2-hydroxyethyl)oxamide and adipic acid or sebacic acid. Chain extension of them was conducted with 2,2′-(1,4-phenylene)-bis(2-oxazoline) and adipoyl biscaprolactamate as combined chain extenders. The chain extended polyesteramides (ExtPEAs) were characterized by IR, 1H NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray scattering, tensile test, and dynamic thermomechanical analysis. The results showed that the ExtPEA(0, m)s were mainly constituted with the diester oxamide alternating units. They had Tm above 140.8°C and the initial decomposition temperature above 298.0°C. They crystallized in similar crystallites to Nylon-66 and were thermoplastic materials with tensile strength up to 31.47 MPa. POLYM. ENG. SCI., 54:756–765, 2014. © 2013 Society of Plastics Engineers
Co-reporter:Chenguo Li;Suqing Li;Jingbo Zhao;Zhiyuan Zhang
Journal of Polymer Research 2014 Volume 21( Issue 7) pp:
Publication Date(Web):2014 July
DOI:10.1007/s10965-014-0498-0
Two nylon-6 oligomers having polymerization degrees of 4.99 and 3.55 terminated with H2N– and HO– groups (H2N-PA-OHs) were prepared by the ring-opening polymerization of caprolactam with ethanolamine at different molar ratios. These oligomers were transformed into HO–terminated nylon-6 oligomers (HO-PA-OHs) through reaction with excessive caprolactone. The transurethane polycondensation of HO-PA-OHs with a diurethanediol, i.e., 1,6-bis(hydroxyethyloxy carbonyl amino)hexane (BHCH), was carried out at 170 °C under normal pressure for 4 h and at 180 °C under a reduced pressure of 3 mmHg for 6.5 h. A series of aliphatic thermoplastic poly(amide urethane)s having different short nylon-6 segments (s-PAUs) was prepared. The s-PAUs were characterized by viscometry, gel permeation chromatography, FT-IR, 1H-NMR, solid 13C CP MAS NMR, differential scanning calorimetry, thermogravimetric analysis, wide angle X-ray scattering and tensile tests. Results showed Mn above 29,762, Mw above 36,725, Tm between 128.73 and 171.69 °C, and initial decomposition temperature over 266.25 °C. Tensile strength reached 31.50 MPa with strain at break up to 447.49 %. Some urea linkages were formed during transurethane polycondensation.
Co-reporter:Yajiao Hao, Mengyu Chen, Jingbo Zhao, Zhiyuan Zhang, and Wantai Yang
Industrial & Engineering Chemistry Research 2013 Volume 52(Issue 19) pp:6410
Publication Date(Web):April 24, 2013
DOI:10.1021/ie302879t
One kind of nylon-610 oligomer (PrePA) was prepared from the reaction of nylon-610 salt with sebacic acid. Polyesteramide prepolymers (PrePEAs) having amide content from 10 to 60 mol % were synthesized through melt polycondensation from adipic acid, 1,4-butanediol, and the PrePA with the catalysis of stannous chloride. Chain extension of the PrePEAs was carried out at 210 °C using 2,2′-(1,4-phenylene)-bis(2-oxazoline) and adipoyl biscaprolactamate as combined chain extenders. The chain extended polyesteramides (ExtPEAs) with intrinsic viscosity up to 0.70 dL/g were synthesized. The ExtPEAs were characterized by FTIR and 1H NMR spectrum, differential scanning calorimetry, wide-angle X-ray scattering, thermogravimetric analysis, tensile test, and enzymatic degradation. The results showed that the ExtPEAs were biodegradable and had Tm from 95.20 to 155.67 °C, initial decomposition temperature over 325.3 °C, and tensile strength up to 33.1 MPa.
Co-reporter:Lizhi Li;Jingbo Zhao;Hao Li;Tong Zhao
Applied Organometallic Chemistry 2013 Volume 27( Issue 12) pp:723-728
Publication Date(Web):
DOI:10.1002/aoc.3070
This paper reports a non-catalyzed environmentally friendly method of synthesizing hyperbranched polymethylvinylborosiloxanes (PMVBSs) and their use to improve the thermal stability of normal addition-curable silicones (ACSs). PMVBSs were synthesized by the direct polycondensation of dimethoxymethylvinylsilane with boric acid at 80–130°C in 1,4-dioxane or diglyme. They were characterized by gel permeation chromatography; FT-IR; 1H, 13C, 29Si and 11B NMR; and TGA. PMVBSs were composed of Si―O―Si and Si―O―B bridges with some unreacted B―OH groups remaining, and had a ceramic yield up to 65.97% at 900°C. PMVBS-modified ACSs (PBS-ACSs) were prepared by curing the PMVBSs with hydrogen-containing silicone oil under Karstedt (platinum divinyltetramethyldisiloxane) catalysis. Thermal stability of PBS-ACSs was characterized by TGA in N2 or air, and ceramic yields as high as 76.7% were obtained. Gas decomposition during the ceramization of PBS-ACSs was examined by TG/mass spectroscopy. The SiBOC ceramics formed were characterized by FT-IR, Raman, 29Si and 11B magic angle spinning NMR and elemental analysis. This method provides a valuable way to improve the thermal stability of ACSs. Copyright © 2013 John Wiley & Sons, Ltd.
Co-reporter:Hui-yun Sun;Tiao Yin 赵京波
Chinese Journal of Polymer Science 2013 Volume 31( Issue 3) pp:452-461
Publication Date(Web):2013 March
DOI:10.1007/s10118-013-1233-8
Two kinds of aliphatic alternating polyesteramide prepolymers were prepared through melt polycondensation from N,N′-bis(2-hydroxyethyl)-adipamide and adipic acid or sebacic acid. Chain extension of them was conducted with 2,2′-(1,4-phenylene)-bis(2-oxazoline) and adipoyl biscaprolactamate as combined chain extenders. The chain extended polyesteramides (ExtPEAs) were characterized by IR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide angle X-ray scattering, tensile test and enzymatic degradation. The results showed that the ExtPEA(4,m)s were mainly constituted with the diester adipamide alternating units. ExtPEA(4,4) and ExtPEA(4,8) had Tm of 83.8°C and 85.8°C and initial decomposition temperature above 310.0°C. They crystallized similarly as Nylon-66 did and were flexible thermoplastic materials with tensile strength up to 25.64 MPa and strain at break up to 737%.
Co-reporter:Yuntao Li, Weijian Han, Hao Li, Jingbo Zhao, Tong Zhao
Materials Letters 2012 Volume 68() pp:101-103
Publication Date(Web):1 February 2012
DOI:10.1016/j.matlet.2011.10.060
ZrB2/ZrC/SiC precursors were prepared in a one-pot reaction of polyzirconoxanesal with boric acid and poly(methylsilylene)ethynylene. The pyrolysis of the precursors at 1400 °C in argon led to formation of the nano-crystalline ZrB2/ZrC/SiC ceramics. The ceramics were characterized by inductively coupled plasma (ICP), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the ceramics were mainly composed of zirconium diboride, zirconium carbide and β-silicon carbide phases. The average size of the ZrB2, ZrC and SiC grains was approximately 100 nm. Elemental analysis showed that the molar ratio of crystal phases was ZrB2/ZrC/SiC = 2/1.35/1, and the total weight ratio of zirconium, boride and silicon was above 81% in the ceramics. The presence of SiC obviously restrained the oxidation of ZrC and ZrB2 at 1000 °C.Highlights► ZrB2/ZrC/SiC ceramic was prepared in one-pot method from liquid precursors. ► The average size of the ZrB2, ZrC and SiC grains was approximately 100 nm. ► Presence of SiC obviously restrained th e oxidation of ZrC and ZrB2 at 1000 °C.
Co-reporter:Shao Yi Xu;Yan Hong Shi;Jing Bo Zhao;Sheng Ling Jiang ;Wan Tai Yang
Polymers for Advanced Technologies 2011 Volume 22( Issue 12) pp:2360-2367
Publication Date(Web):
DOI:10.1002/pat.1771
Abstract
This paper provided an easy and flexible method to synthesize high molecular weight polyesters by polycondensation and chain extension. Low molecular weight polybutylene adipate, polybutylene succinate, and poly(butylene succinate-co-butylene adipate) (PBSA) were synthesized through melt condensation polymerization from adipic acid and/or succinic acid with butanediol. The prepolyesters obtained had different amount of COOH and OH terminal groups. Chain extension of them was carried out at 180–240°C using 2,2′-(1,4-phenylene)-bis(2-oxazoline) and adipoyl biscaprolactamate as combined chain extenders. The influencing factors of the chain extension were studied. At the optimal conditions, chain-extended polybutylene adipate with Mn up to 39,100, polybutylene succinate with intrinsic viscosity of 0.99 dl/g, and PBSA with intrinsic viscosity from 0.73 to 0.81 dl/g were synthesized. The chain-extended polyesters were characterized by IR spectrum, 1H NMR spectrum, differential scanning calorimetry, thermogravimetric analysis (TGA), wide angle X-ray scattering, and tensile test. The thermal analysis showed that chain extension often led to slight decrease of the regularity, the crystallinity, and the melting point. This deterioration of the properties is not harmful enough to impair their thermal properties and obstruct them from being used as biodegradable thermoplastics. The TGA showed that the chain-extended polyesters were stable with initial decomposition temperature over 354.7°C. The tensile strength of the chain extended PBS and PBSAs with butylene adipate units less than 20 mol% was in the range of 18.95–31.22 MPa. Copyright © 2010 John Wiley & Sons, Ltd.
Co-reporter:Shiyue Liu, Chenguo Li, Jingbo Zhao, Zhiyuan Zhang, Wantai Yang
Polymer 2011 Volume 52(Issue 26) pp:6046-6055
Publication Date(Web):13 December 2011
DOI:10.1016/j.polymer.2011.10.048
A Nylon-6 oligomer (PrePA) was synthesized by ring-opening polymerization from ε-caprolactam with 2-amino-ethanol under the catalysis of H3PO3. Polyesteramide prepolymers (PrePEAs) having amide content from 10 to 60 mol% were prepared through melt polycondensation from adipic acid, 1,4-butanediol and the PrePA. Chain extension of PrePEAs was carried out at 200 °C using 2,2′-(1,4-phenylene)-bis(2-oxazoline) and carbonylbiscaprolactamate as combined chain extenders. The chain-extended polyesteramides (ExtPEAs) with intrinsic viscosity up to 0.61 dL/g were synthesized. The ExtPEAs were characterized by FT-IR and 1H NMR spectra, differential scanning calorimetry, wide angle X-ray scattering, thermogravimetric analysis and tensile test. The results showed that the ExtPEAs mainly crystallized in the Nylon-6 crystallites. ExtPEAs had Tg from −46.71 to 4.28 °C, Tm from 106.69 to 139.92 °C, thermal stability with initial decomposition temperature over 339 °C, tensile strength up to 30.89 MPa and stain at break higher than 797.1%. These ExtPEAs were strong, thermally stable and tough thermoplastic polymers.
Co-reporter:Chao Qun Huang;Si Yang Luo;Shao Yi Xu;Jing Bo Zhao;Sheng Ling Jiang ;Wan Tai Yang
Journal of Applied Polymer Science 2010 Volume 115( Issue 3) pp:1555-1565
Publication Date(Web):
DOI:10.1002/app.31160
Abstract
Low-molecular-weight HOOC-terminated poly(butylene adipate) prepolymer (PrePBA) and poly(butylene succinate) prepolymer (PrePBS) were synthesized through melt-condensation polymerization from adipic acid or succinic acid with butanediol. The catalyzed chain extension of these prepolymers was carried out at 180–220°C with 2,2′-(1,4-phenylene)-bis(2-oxazoline) as a chain extender and p-toluenesulfonic acid (p-TSA) as a catalyst. Higher molecular weight polyesters were obtained from the catalyzed chain extension than from the noncatalyzed one. However, an improperly high amount of p-TSA and a high temperature caused branching or a crosslinking reaction. Under optimal conditions, chain-extended poly(butylene adipate) (PBA) with a number-average molecular weight up to 29,600 and poly(butylene succinate) (PBS) with an intrinsic viscosity of 0.82 dL/g were synthesized. The chain-extended polyesters were characterized by IR spectroscopy, 1H-NMR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, wide-angle X-ray scattering, and tensile testing. DSC, wide-angle X-ray scattering, and thermogravimetric analysis characterization showed that the chain-extended PBA and PBS had lower melting temperatures and crystallinities and slower crystallization rates and were less thermally stable than PrePBA and PrePBS. This deterioration of their properties was not harmful enough to impair their thermal processing properties and should not prevent them from being used as biodegradable thermoplastics. The tensile strength of the chain-extended PBS was about 31.05 MPa. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Yuan Sui;Jingbo Zhao;Shenghua Gan;Hongchi Zhao;Wantai Yang
Journal of Applied Polymer Science 2007 Volume 105(Issue 2) pp:877-884
Publication Date(Web):6 APR 2007
DOI:10.1002/app.24746
This article presents the ring-opening polymerization of ε-caprolactone (ε-CL) from PP film modified with an initiator layer composed of OSn(Oct) groups. This method consists of two steps: (1) Sn(Oct)2 exchanged with the hydroxyl groups on the surface of PP film, forming the OSn(Oct) groups bonded on the surface; (2) surface-initiated ring-opening polymerization of ε-CL with the OSn(Oct) groups. The initiator layer is characterized by attenuated total reflectance-Fourier transform infrared (ATR-FTIR), contact angles, and X-ray photoelectron spectroscopy (XPS). The growth of PCL chains from the initiator layer through ring-opening polymerization is successfully achieved. ATR-FTIR, XPS, and scanning electron microscope (SEM) are also used to characterize the grafted film. XPS results reveal that the PCL chains cover the surface of PP film after 4 h. The SEM images reveal that the PCL chain clusters grow into regular spheroidal particles, which can be changed into other different morphology by treated with different solvents. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Co-reporter:Jing Bo Zhao;Wan Tai Yang;Kai Yong Li
Journal of Applied Polymer Science 2007 Volume 106(Issue 1) pp:590-598
Publication Date(Web):26 JUN 2007
DOI:10.1002/app.26635
HO-terminated polybutylene adipate (HO-PBA-OH) with molecular weight from 1040 to 3540 and HO-terminated polybutylene succinate (HO-PBS-OH) with intrinsic viscosity of 0.37 dL/g were synthesized through melt condensation polymerization from adipic acid or succinic acid with excess of butanediol. Chain extension of HO-PBA-OH or HO-PBS-OH with adipoyl biscaprolactamate and terephthaloyl biscaprolactamate was carried out at 200–240°C under reduced pressure. At the optimal conditions, chain-extended PBA with Mn up to 50,700, and Mw up to 125,700 was synthesized, and the chain-extended PBS with intrinsic viscosity of 1.25 dL/g was obtained. Meanwhile, p-toluenesulfonic acid, SnCl4 and zinc acetylacetonate catalyzed chain-extending reaction of HO-PBA-OH and HO-PBS-OH was also studied. The chain-extended polyesters were characterized by IR spectra, 1H-NMR spectra, and differential scanning calorimetry (DSC). The chain extension proceeds through the elimination of caprolactam rings in the chain-extenders, the adipoyl groups or the terephthaloyl groups couple the hydroxyl-terminated polyesters together and make the molecular weight of PBA or PBS increased, whether the acid catalyst such as p-toluenesulfonic acid was present or not. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Co-reporter:Zhao Jing-Bo;Xie Ze-Min
Journal of Applied Polymer Science 2005 Volume 97(Issue 4) pp:1484-1490
Publication Date(Web):23 MAY 2005
DOI:10.1002/app.21890
1,3-Dichloro-1,1,3,3-tetraphenyldisilazane (DCTPS) with 71.6% yield was synthesized by the reaction of hexaphenylcyclotrisilazane (HPCT) with Ph2SiCl2 catalyzed by dibutyltin dilaurate. A ring-closure reaction of DCTPS was carried out with BuLi in xylene–hexane mixture solvent; 1,3-bis(chlorodiphenylsilyl)-2,2,4,4-tetraphenyl-cyclodisilazane (BcPTPC) with 73.2% yield was obtained. Hydrolysis of BcPTPC in ether–triethylamine solvent resulted in 71.9% yield of 1,3-bis(diphenylhydroxysilyl)-2,2,4,4-tetraphenylcyclodisilazane (BHPTPC). By condensation polymerization of BHPTPC with α,ω-bis(diethylamino)-oligo-dimethylsiloxane, a kind of alternate copolymer constructed by 1,3-bis(diphenylsilyl)-2,2,4,4-tetraphenylcyclodisilazane units with oligo-dimethylsiloxane segments [P(BPTPC-alt-ODMS)] was synthesized. BcPTPC, BHPTPC as well as P(BPTPC-alt-ODMS) were characterized by 29Si-NMR spectra, FT-IR spectra, and elemental analysis. DGA study shows that P(BPTPC-alt-ODMS)s are thermally stable. The thermal decomposition onsets of P(BPTPC-alt-ODMS)s are all above 520°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1484–1490, 2005
Co-reporter:Jing-Bo Zhao;Xiao-Feng Wu;Wan-Tai Yang
Journal of Applied Polymer Science 2004 Volume 92(Issue 5) pp:3333-3337
Publication Date(Web):25 MAR 2004
DOI:10.1002/app.20330
Aliphatic HO-terminated polyesters such as poly(diethylene glycol adipate) (PDEGA), poly(ethylene adipate) (PEA), and poly(butylene succinate) (PBS) with molecular weight from 1247 to 1948 were synthesized through condensation polymerization from adipic acid or butanedioic acid with excess diethylene glycol, ethylene glycol, or butylene glycol. From the HO-terminated polyesters, polyesters with high molecular weight were synthesized by a chain-extending reaction with octamethylcyclotetrasilazane (OMCT) or hexaphenylcyclotrisilazane (HPCT) as chain-extenders. Gel permeation chromatography (GPC) characterization shows that the Mn of chain-extended PDEGA is from 12,644 to 32,870, Mw is from 22,786 to 70,048; Mn of chain-extended PEA is 11,368, Mw is 19,877; and the Mn of chain-extended PBS is from 9823 to 39,873, Mw is from 18,823 to 137,192. The chain-extended polyesters were also characterized by 1H-NMR spectrum, IR spectra, and DSC spectra. The multiple peaks at 7.37 and 7.67 ppm in the 1H-NMR spectrum of chain-extended PDEGA and peaks at 3051.1 and 1593.4 cm−1 in the IR spectrum of the chain-extended PBS show the evidence of the SiPh2 structure in the polyesters obtained from the chain-extending reaction. DSC study shows that the bulky SiPh2 units introduced by the chain-extending reaction lower the regularity of the polyester chains, so the melting point of the chain-extended PBS and PEA decreases compared to that of the original HO-terminated PBS and PEA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3333–3337, 2004
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