Toughening thermally resistant resin without sacrificing outstanding performances of original resin is still a big challenge. Herein, a novel liquid crystalline hyperbranched polysiloxane (LCPSi) with wide transition temperature range and terminal amino groups was facilely synthesized, which was then used to toughen epoxy (EP)/cyanate (CE) ester (the weight ratio of EP to CE is 1:9, coded as eCE). Results show that a small addition of LCPSi can remarkably improve the integrated performances of eCE resin including toughness, stiffness, thermal and dielectric properties. For example, the impact strength and flexural modulus of 1.5LCPSi/eCE resin (with 1.5 wt% LCPSi) are 2.3 and 1.5 times of those of eCE resin, respectively; meanwhile the initial thermal decomposition temperature (T_di) at which the weight loss of the sample reaches 5 wt% of the former is 18.9°C higher than that of the latter; moreover, both dielectric constant and loss decrease. Those attractive performances demonstrate that LCPSi is a multi-functional modifier of eCE resin. The origin behind was intensively discussed through the structure–property relationship. Copyright © 2015 John Wiley & Sons, Ltd.

Functional polymeric composites based on expanded graphite (EG) have obtained wide attentions worldwide owing to their great potential in many fields. Poor dispersion is the main problem limiting the full exploitation of outstanding properties of these composites. To solve the problem, a facile and green method, named as in situ vacuum exfoliation plus microwave curing (VEMC) technique, is developed. The biggest merit of the VEMC process is that worm-like EG particles are directly used to prepare composites, and no solvent or other chemical is needed, so the chemical structure and original advantages of exfoliatable fillers can be fully utilized in the composites. A series of composites based on EG particles and epoxy (EP) resin, coded as new-EG/EP, were fabricated using the VEMC technique. Interestingly, worm-like EG particles are found to be in situ exfoliated into nanosheets, and these sheets are well dispersed in the resin. Compared with the composites prepared using traditional processes, new-EG/EP composites have much higher dielectric constants, demonstrating that the VEMC technique is efficient to prepare composites with good dispersion based on exfoliatable fillers. POLYM. COMPOS., 36:385–388, 2015. © 2014 Society of Plastics Engineers

Developing green and high efficiency inorganic flame retardants is the trend of preparing flame retarding polymer composites. Aluminum phosphates (t-hAP) with uniform, small dimension, and hexagonal structure were facilely synthesized, which have similar size (1–2 μm) but different structures from commercial spherical-like aluminum phosphate (cAP). The flame retardance of bismaleimide (BD)/t-hAP and BD/cAP composites were intensively investigated. t-hAP is proved to have much better flame retarding effect than cAP, but also exhibits advantages over Mg(OH)₂ and Al(OH)₃. With only 5 wt % addition of t-hAP into BD resin, the peak and total heat releases as well as total smoke production significantly reduce 42.3, 47.8, and 67.3%, respectively; besides, better data are obtained as the loading of t-hAP increases to 10 wt %. These attractive data result from three effects induced by t-hAP. Besides the better protection role of sheet structure, the strong hydrogen bonding between t-hAP and BD resin endows the composite with good dispersion of t-hAP and high crosslinking density; moreover, t-hAP releases H₂O and NH₃, diluting flammable gases during combustion. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41089.

Advanced wave-transparent composites are the key materials for many cutting-edge industries including aviation and aerospace, which should have outstanding heat resistance, low dielectric constant and loss as well as good mechanical properties. A novel kind of high-performance wave-transparent composites based on surface-modified aluminum phosphate AlPO₄(KH-550) and cyanate ester (CE) was first developed. The dielectric and dynamic mechanical properties of AlPO₄(KH-550)/CE composites were investigated intensively. Results show that AlPO₄(KH-550)/CE composites have decreased dielectric loss and higher storage moduli than pure CE resin; in addition, the composites with suitable AlPO₄(KH-550) concentration remain the outstanding thermal property and low dielectric constant of pure CE resin. The reasons attributing to these results are discussed from the effects of AlPO₄(KH-550) on the key aspects such as morphology, curing mechanism, and interfacial adhesion of composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

A new hyperbranched polysiloxane containing maleimide (HPMA) was synthesized through the reaction between N-(4-hydroxyphenyl) maleimide and 3-glycidoxypropyltrimethoxysilane, which was then used to prepare cyanate ester (CE) resin-based hybrids (coded as HPMAx/CE, where x is the weight fraction of HPMA in the hybrid). The curing behavior of uncured hybrids and the typical properties (impact strength and dielectric properties) of cured hybrids were systemically investigated. Results show that the performance of hybrids is greatly related with the content of HPMA. Hybrids have obviously lower curing temperature than CE, overcoming the poor curing characteristics (higher curing temperature and longer curing time) of neat CE, for example, the curing peak temperature of HPMA20/CE is about 65°C lower than that of CE. In the case of cured resin and hybrids, the hybrids exhibit decreased dielectric constant and loss than CE resin; moreover, the former also exhibits lower water absorption than the latter. Specifically, the dielectric loss of HPMA15/CE hybrid is only about 27% of that of neat CE resin. In addition, the hybrids with suitable contents of HPMA have significantly improved impact strengths. The overall improved properties suggest that HPMAx/CE hybrids have great potential in applications needing harsh requirements of curing feature, dielectric properties, and toughness. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

High curing temperature is the key drawback of present heat resistant thermosetting resins. A novel epoxy-functionalized hyperbranched poly(phenylene oxide), coded as eHBPPO, was synthesized, and used to modify 2,2′-bis (4-cyanatophenyl) isopropylidene (CE). Compared with CE, CE/eHBPPO system has significantly decreased curing temperature owing to the different curing mechanism. Based on this results, cured CE/eHBPPO resins without postcuring process, and cured CE resin postcured at 230°C were prepared, their dynamic mechanical and dielectric properties were systematically investigated. Results show that cured CE/eHBPPO resins not only have excellent stability in dielectric properties over a wide frequency range (1–10⁹Hz), but also show attractively lower dielectric constant and loss than CE resin. In addition, cured CE/eHBPPO resins also have high glass transition temperature and storage moduli in glassy state. These attractive integrated performance of CE/eHBPPO suggest a new method to develop high performance resins. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

An improved method is developed to synthesize octavinylsilsesquioxanes (VPOSS) with shorter time and higher yield, and then VPOSS is used to prepare new hybrids based on bismaleimide-triazine (BD/CE) resin, coded as VPOSS/BD/CE. The effect of the content of VPOSS on the key properties including curing behavior, thermal, mechanical, and dielectric properties as well as water resistance of VPOSS/BD/CE hybrids were systematically discussed. Compared with BD/CE resin, hybrids show similar curing behavior but different chemical structures and thus macro-performance. These key properties of hybrids are dependent on the content of VPOSS, all hybrids show significantly improved dielectric properties, water resistance, and dimensional stability; moreover, the hybrids with suitable content of VPOSS have bigger impact strengths. Specifically, with the addition of 7 wt% VPOSS to BD/CE resin, the dielectric constant decreases from 3.7 to 3.2, the dielectric loss decreases 55%, and the coefficient of thermal expansion reduces 23%; moreover, the glass transition temperature and initial decomposition temperature increase about 15°C. The attractive integrated properties suggest that VPOSS/BD/CE hybrids have great potential to be used as structural and functional materials for many cutting-edge fields. Copyright © 2011 John Wiley & Sons, Ltd.

A novel method is proposed to synthesize new mesoporous silica containing amine groups (MPSA), and it was further employed to modify bismaleimide-dialllyl bisphenol (BD)/cyanate ester (CE) resin to form novel MPSA/BD/CE hybrids; in addition, the typical properties of MPSA/BD/CE were systematically investigated. Results show that these hybrids have very low dielectric constant and loss as well as good thermal properties. Compared with BD/CE resin, all hybrids have not only decreased dielectric constant and loss but also similar dependence of dielectric properties on frequency over the whole frequency from 10 to 10⁶ Hz. Specifically, with the addition of MPSA to BD/CE resin, the dielectric constant reduces from 3.5 to 3.0, and the dielectric loss is only 85% of that of BD/CE resin. Note that all hybrids show better thermal resistance (reflected by higher glass transition temperature, decreased maximum degradation rate, and higher char yield at 800°C) than BD/CE resin. All these differences in macro-properties are attributed to the different structure between MPSA/BD/CE hybrids and BD/CE resin. Copyright © 2011 John Wiley & Sons, Ltd.

New high performance insulating composites based on hollow silica tubes (mHST) and bismaleimide/diallylbisphenol A (BDM/DBA) resin, which exhibit improved toughness, dielectric properties, and flame retardancy, were successfully developed. The effect of the amount of mHST on the properties of composites was systematically studied. Results show that the impact strength of the composite with 0.5 wt% mHST is about 2.2 times that of BDM/DBA resin. In addition, compared with BDM/DBA resin, the composites show lower and stable dielectric constant, better frequency stability of dielectric loss, significantly improved flame retardancy, and similarly outstanding thermal resistance. The reasons behind these attractive integrated properties are discussed from the view of structure–property relationship. Copyright © 2011 John Wiley & Sons, Ltd.

Novel glycidyl methacrylate–butyl acrylate–maleic anhydride (GBM) terpolymers with different molecular weights were synthesized by radical polymerization and characterized using fourier transform infrared, nuclear magnetic resonance (¹H-NMR and ¹³ C-NMR), and gel permeation chromatography. Each GBM terpolymer was used to modify aluminum nitride (AlN), and the modified AlN, coded as AlN(GBM), was added to 2,2′-bis(4-cyanatophenyl)isopropylidene (CE) resin for preparing composites. Composites based on original AlN or γ-(2,3-epoxypropoxy)propyltrimethoxysilane-modified AlN (AlN(K)) were also prepared for comparison. Although GBM and γ-(2,3-epoxypropoxy)propyltrimethoxysilane have similar reactive groups, the results indicate that GBM shows more attractive integrated advantages, reflected by the fact that CE/AlN(GBM) composites have better thermal stability, higher thermal conductivity, and higher glass transition temperature than those of CE/AlN(K). These properties result from better dispersion of fillers, improved interfacial adhesion between fillers and CE resin, and increased cross-linking density. This study demonstrates that the nature of the coupling agents is an important factor to develop high performance composites for cutting-edge industries. Copyright © 2011 John Wiley & Sons, Ltd.

A new addition curable silicone resin (ASiR) system with excellent dielectric and thermal properties was developed, which consists of only two components: poly(methylphenylvinylsiloxane) (PMPVSi) and an end-capped hydrogen-functionalized hyperbranched polysiloxane (EHFHPSi). PMPVSi is synthesized by a green and controllable process; EHFHPSi is first synthesized via A₂ + B₃ approach, and then end-capped by hexamethyldisiloxane (HMDS). Three formulations were designed to investigate the optimum stoichiometry. Results show that cured ASiR resins have greatly different dielectric and thermal properties because of the different chemical structure of cured networks resulting from the different stoichiometries. The resin with a suitable stoichiometry has not only excellent dielectric properties including extremely low dielectric constant (2.96 at 1 Hz) and loss (0.0003 at 1 Hz) as well as good stability on frequency, but also outstanding thermal resistance, exhibiting great potential to be used as a new kind of high-performance resins for many cutting-edge industries, especially the microelectronic and insulation fields. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers

Novel modified cyanate ester resins (EPMPS-n/BADCy), with significantly decreased dielectric loss and improved toughness, were developed by copolymerizing the cyanate ester resin, 2, 2′-bis (4-cyanatophenyl) isopropylidene resin) (BADCy), with an epoxidized methyl phenyl silicone resin (EPMPS). The curing behavior of EPMPS-n/BADCy and the typical properties of the corresponding cured EPMPS-n/BADCy were systematically investigated. The results show that the addition of EPMPS into BADCy can not only accelerate the curing reaction of BADCy, but also decrease dielectric loss and enhance the impact strength as well as water resistance. For example, in the case of the modified BADCy resin with 15 wt%EPMPS, its impact strength is 17.8 kJ/m², about 3 times of that of pure BADCy resin and its water absorption is only 0.25%, about one-half of that of pure BADCy resin. In addition, while the dielectric loss is only 79% of that of pure BADCy resin, while its dielectric constant remains constant over the frequency range of 1KHz-1 MHz. The above results suggest that EPMPS-n/BADCy have great potential to be used as the matrix or adhesive for advanced composites. Copyright © 2009 John Wiley & Sons, Ltd.

High-performance thermosetting resins should have good toughness and stiffness, so simultaneously toughening and stiffening is the main target in developing high-performance resins. A novel modified cyanate ester resin with improved toughness and stiffness was developed by copolymerizing 2,2′-bis(4-cyanatophenyl)isopropylidene (CE) with hyperbranched polyphenylsilsesquioxane (HBPPSi). The mechanical properties and their nature were systematically investigated from the viewpoint of structure-property relations using positron annihilation lifetime spectroscopy and spectral analyses. It is found that a suitable content of HBPPSi in CE resin can effectively improve toughness and stiffness. In the case of the CE resin modified with 10 wt% HBPPSi, its impact and flexural strengths are 21 kJ m⁻² and 148 MPa, respectively, about 2.6 and 1.4 times of those of neat CE resin. The flexural modulus increases from 3.0 (for neat CE resin) to 3.4 GPa. The results of dynamic mechanical analyses also corroborate the static mechanical properties. The improved toughness and stiffness of CE resin can be attributed to the synergistic effect resulting from changes of both polymer chain structure and aggregation state structure. These attractive features of HBPPSi/CE resins suggest that the method proposed herein may be a new approach for the development of high-performance resins for cutting-edge industries. Copyright © 2011 Society of Chemical Industry

High-performance hyperbranched poly(phenylene oxide)-modified bismaleimide resin with high thermal stability, low dielectric constant, and loss was developed, which is made up of hyperbranched poly(phenylene oxide) (HBPPO), 4,4′-bismaleimidodiphenylmethane (BDM), and o, o′-diallylbisphenol A (DBA). The curing reactivity, morphology, and performance of BDM/DBA/HBPPO resin were systemically investigated, and similar investigations for BDM/DBA resin were also carried out for comparison. Results show that BDM/DBA/HBPPO and BDM/DBA resins have similar curing mechanism, but the former can be cured at lower temperature than the later; in addition, cured BDM/DBA/HBPPO resin with suitable HBPPO content has better thermal stability and dielectric properties (lower dielectric constant and loss) than BDM/DBA resin. The difference in macroproperties between BDM/DBA/HBPPO and BDM/DBA resins results from the different chemical structures and morphologies of their crosslinking networks. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

A novel kind of high-performance hybrids (coded as POSS-NH₂/BT) with significantly decreased curing temperature, lowered dielectric constant and loss, and improved thermal resistance were developed, which were prepared by copolymerizing bismaleimide with cage octa(aminopropylsilsesquioxane) (POSS-NH₂) to produce POSS-containing maleimide, and then co-reacted with 2,2′-bis(4-cyanatophenyl) isopropylidene. The curing behavior and typical properties of cured POSS-NH₂/BT were systematically investigated. Results show that POSS-NH₂/BT hybrids have lower curing temperatures than BT resin because of the additional reactions between OCN and amine groups. Compared with BT resin, all hybrids show improved dielectric properties. Specifically, hybrids have slightly decreased dielectric constants and similar dependence of dielectric constant on frequency over the whole frequency from 10 to 10⁶ Hz; more interestingly, the dielectric loss of hybrids is only 25% of that of BT resin at the frequency lower than 10⁵ Hz, whereas all hybrids and BT resin have almost equal dielectric loss when the frequency is higher than 10⁵ Hz. In addition, POSS-NH₂/BT hybrids also show good thermal and thermo-oxidative stability compared with BT resin. All these differences in macroproperties are attributed to the difference in chemical structure between POSS-NH₂/BT hybrids and BT resin. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

A high-performance matrix is the key base for the fabrication of high-frequency copper-clad laminates. A high-performance resin system based on commercial poly(phenylene oxide) (PPO) and 2,2′-bis(4-cyanatophenyl) isopropylidene (BADCy), coded as PPO-n/BADCy (where n is the weight parts of PPO per 100 weight parts of BADCy), was developed. The effect of PPO on the key properties, including the dielectric and thermal properties, water resistance, and toughness, of the cured resins was investigated extensively. The results show that PPO not only catalyzed the curing reaction of BADCy but also reacted with BADCy to form a single-phase structure. Furthermore, compared with the cured BADCy resin with 1 phr epoxy resin as a catalyst, the cured PPO-n/BADCy resins had significantly increased impact strengths and decreased dielectric constants, loss, and water resistance. The reasons behind these desirable improvements are discussed from the view of structure–property relationships. These results suggest that the PPO-n/BADCy system has great potential to be used as a matrix for high-frequency copper-clad laminates or other advanced composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

A novel hyperbranched poly(phenylene oxide) (HBPPO) modified 2,2′-bis(4-cyanatophenyl) isopropylidene (BCE) resin system with significantly reduced curing temperature and outstanding dielectric properties was developed, and the effect of the content of HBPPO on the curing behavior and dielectric properties as well as their origins was thoroughly investigated. Results show that BCE/HBPPO has significantly lower curing temperature than BCE owing to the different curing mechanisms between the two systems, the difference also brings different crosslinked networks and thus dielectric properties. The dielectric properties are frequency and temperature dependence, which are closely related with the content of HBPPO in the BCE/HBPPO system. BCE/2.5 HBPPO and BCE/5 HBPPO resins have lower dielectric constant than BCE resin over the whole frequency range tested, while BCE/10 HBPPO resin exhibits higher dielectric constant than BCE resin in the low frequency range (<10⁴ Hz) at 200°C. At 150°C or higher temperature, the dielectric loss at the frequency lower than 10² Hz becomes sensitive to the content of HBPPO. These phenomena can be attributed to the molecular relaxation. Two relaxation processes (α- and β-relaxation processes) are observed. The β-relaxation process shifts toward higher frequency with the increase of temperature because of the polymer structure and chain flexibility; the α-relaxation process appears at high temperature resulting from the chain-mobility effects. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

New transparent zinc oxide (ZnO)/silicone nanocomposites with outstanding integrated properties, including a high UV-shielding efficiency and transparency, bigger thermal conductivity, and lower dielectric constant, were successfully developed; they were prepared by the uniform dispersion of organic modified nano-ZnO in a silicone matrix through in situ polymerization. The ZnO precursor was prepared by a direct precipitation method, which was then calcinated at different temperatures to produce nano-ZnO with various morphologies and sizes. The effects of the size, surface nature, and content of nano-ZnO on the key properties (e.g., optical and dielectric properties, thermal conductivities) of the composites were systematically investigated. The results show that the organic nano-ZnO prepared by 3-methacryloxypropyltrimethoxysilane can increase the dispersion of nano-ZnO in silicone resin, and the interfacial adhesion between inorganic and organic phases, and consequently improve the integrated properties of nanocomposites. The increase of the particle content and size of ZnO in composites can lead to high thermal conductivity and UV-shielding efficiency but lower visible-light transparency, so there is an optimum content and size of ZnO in composites to obtain the best integrated properties of the composites. Specifically, the nanocomposite containing 0.03 wt % organic nano-ZnO with an average size of 46 ± 0.4 nm not only had a high visible-light transparency, UV-shielding efficiency, and thermal conductivity but also possessed a low dielectric constant and loss and met the requirements of high-performance electronic packaging for high-power light-emitting diodes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Curing kinetics and mechanism determine the structure and property of thermosetting resins and related composites. The curing kinetics and mechanism of a novel high performance resin system based on hyperbranched polysiloxane (HBPSi), 2,2′-diallylbisphenol A modified bismaleimide (BD), and cyanate ester (CE) resins for Resin Transfer Molding (RTM) technique were systemically studied by Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR) spectra, and torque rheometer. Results show that the addition of HBPSi to BD/CE resin not only decreases the initial curing temperature and apparent activation energy, but also changes the curing mechanism, and thus the structure and properties of resultant crosslinked networks. An “Interpenetrating network (IPN)-coupling structure” is proposed to be formed in the HBPSi/BD/CE system, which is different from traditional “IPN” structure in BD/CE resin. The simulation of curing reaction suggests that the variety of the curing activity leads to the difference between the curing behaviors of BD/CE and HBPSi/BD/CE resins, which is in good agreement with FTIR and DSC analyses. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

A novel toughened cyanate ester (CE) resin with good dielectric properties and thermal stability was developed by copolymerizing 2,2′-bis(4-cyanatophenyl)iso-propylidene (BCE) with a combined modifier (HBPSiEP) made up of hyperbranched polysiloxane (HBPSi) and epoxy (EP) resin. HBPSi was synthesized through the hydrolysis of 3-(trimethoxysilyl)propyl methacrylate. The effect of differing stoichiometries of HBPSiEP on the curing characteristics and performance of BCE resin is discussed. Results show that the incorporation of HBPSiEP can not only effectively promote the curing reaction of BCE, but can also significantly improve the toughness of the cured BCE resin. In addition, the toughening effect of HBPSiEP is greater than single EP resin. For example, the impact strength of modified BCE resin with 30 wt% of HBPSiEP is 23.3 KJ/m², which is more than 2.5 times of that of pure BCE resin, while the maximum impact strength of EP/BCE resin is about 2 times of pure BCE resin. It is worthy to note that HBPSiEP/BCE resins also exhibit improved thermal stability, dielectric properties, and flame retardancy, suggesting that the novel toughened CE resins have great potentiality to be used as a matrix for advanced functional composites or electronic packing resins. Copyright © 2009 John Wiley & Sons, Ltd.

Novel modified cyanate ester (CE) resins with decreased dielectric loss, improved thermal stability, and flame retardancy were developed by copolymerizing CE with hyperbranched phenyl polysiloxane (HBPPSi). HBPPSi was synthesized through the hydrolysis of phenyltrimethoxysilane, and its structure was characterized by ¹H-NMR, ²⁹Si-NMR, and Fourier transform infrared spectra. The effect of the incorporation of HBPPSi into CE resin on the curing behavior, chemical structure of cured networks, and typical performance of HBPPSi/CE resins were systemically evaluated. It is found that the incorporation of HBPPSi into CE network obviously not only catalyzes the curing of CE, but also changes the chemical structure of resultant networks, and thus results in significantly decreased dielectric loss, improved thermal stability, and flame retardancy as well as water absorption resistance. For example, in the case of the modified CE resin with 10 wt% HBPPSi, its limited oxygen index is about 36.0, about 1.3 times of that of neat CE resin, its char yield at 800°C increases from 31.6 to 35.4 wt%; in addition, its dielectric loss is only about 61% of that of neat CE resin at 1 kHz. All these changes of properties are discussed from the view of the structure–property relationship. The significantly improved integrated properties of CE resin provide a great potential to be used as structural and functional materials for many cutting-edges fields. Copyright © 2011 John Wiley & Sons, Ltd.

A novel kind of solventless silicone hybrids (SSiH) containing branched poly(methylphenylvinylsiloxane) (PMPVSi), end-capped hydrogen-functionalized hyperbranched polysiloxane (EHFHPSi), and octavinyl-polyhedral oligomeric silsesquioxane (OVPOS) was developed through a hydrosilylation reaction. Each of the three basic components was synthesized by harmless and recyclable methods. The new hybrids are considerably suitable for vacuum pressure impregnation process, and can serve as an excellent class C insulating material. The effect of differing stoichiometries of OVPOS and EHFHPSi on the performance of cured hybrids is discussed. Results show that SSiH hybrids possess excellent dielectric and thermal properties as well as low viscosity. The reduction in the dielectric constant and the improvement of thermal property of SSiH hybrids can be explained by the unique structure and morphology of hybrids resulting from the presence of OVPOS and EHFHPSi. The novel silicone hybrids exhibit great potential to be used for many cutting-edge industries, especially the microelectronic and insulation fields. Copyright © 2010 John Wiley & Sons, Ltd.

High performance matrix is the key base for preparing advanced composites via resin transfer molding (RTM). A novel high performance modified maleimide-triazine (BT) resin system (coded as MBT) for RTM was developed, which is made of 4,4′-bismaleimidodi- phenylmethane, o,o'-diallylbisphenol A, 2,2′-bis (4-cyanatophenyl) isopropylidene, and hyperbranched polysiloxane (HBPSi). The effects of HBPSi on the processing and performance parameters of MBT system are evaluated. Results show that the processing characteristics of the MBT system are greatly dependent on the content of HBPSi in the system, while three MBT resins developed in this paper have significantly better integrated properties than BT resin. For example, compared to original BT resin, MBT resins have enlarged pot life (>8 hr) and good reactivity; more interestingly, cured MBT resins exhibit better dielectric properties and moisture resistance; in addition, MBT resins with suitable content of HBPSi have improved flexural and impact strengths as well as outstanding thermal property, suggesting that MBT system is the right kind of matrices with great potentiality for fabricating advanced structural and functional composites via RTM technique. Copyright © 2010 John Wiley & Sons, Ltd.

High curing temperature is the key disadvantage of cyanate esters. A novel catalyst system was developed, which is a hybrid catalyst system (HC) consisting of UV activated tricarbonyl cyclopentadienyl manganese (Catalyst I) and Catalyst II derived from dibutyl tin dilaurate. The effect of HC on the reactivity of 2, 2′-bis(4-cyanatophenyl) isopropylidene (BADCy) monomer, and that on the dielectric and thermal properties of cured resin were investigated. Results show that HC displays an attractive synergy effect on catalyzing BADCy over its two components. Compared with the curing exothermic peak of BADCy, that of BADCy/HC system appears at significantly lower temperature (which is at least 120°C lower than the former). In addition, cured BADCy/HC resin also exhibits interesting synergy effect in integrated performance, that is, it has much better thermal resistance and dielectric properties than cured BADCy, BADCy/Catalyst I, and BADCy/Catalyst II resins. The BADCy/HC resin can be used as high performance matrices for advanced composites and adhesives. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers

Three composites based on cyanate (CE) resin, aluminum nitride (AlN), surface-treated aluminum nitride [AlN(KH560)], and silicon dioxide (SiO₂) for microelectronic packaging, coded as AlN/CE, AlN(KH560)-SiO₂(KH560)/CE, and AlN-SiO₂/CE composite, respectively, were developed for the first time. The thermal conductivity and dielectric constant of all composites were investigated in detail. Results show that properties of fillers in composites have great influence on the thermal conductivity and dielectric constant of composites. Surface treatment of fillers is beneficial to increase the thermal conductivity or reduce dielectric constant of the composites. Comparing with binary composite, when the filler content is high, ternary composites possess lower thermal conductivity and dielectric constant. The reasons leading to these outcomes are discussed intensively. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers

Viscoelastic ature is one of the key features of polymeric composites. A series of cyanate ester (CE)-based composites with different aluminum nitride (AlN) contents for high performance electronic packaging, coded as AlN/CE, were developed; the viscoelastic nature of AlN/CE composites was intensively investigated by employing dynamic mechanical analysis (DMA). Results show that the AlN content has a great effect on dynamic mechanical properties of AlN/CE composites. The storage modulus in the glassy region increases linearly with the addition of AlN as well as the increase of AlN content. Meanwhile, all composites also exhibit notably higher loss modulus than cured CE resin due to the appearance of new energy dissipation forms. In addition, the incorporation of AlN has a significant effect on damping factor peak. All reasons leading to these phenomena are analyzed from the view of structure–property relationship. Copyright © 2009 John Wiley & Sons, Ltd.

Thermodegradation behaviors of novel aluminum phosphate/cyanate ester (AlPO₄(KH550)/CE) composites were studied in detail. Results show that thermodegradation behaviors and kinetic parameters of AlPO₄(KH550)/CE composites are greatly dependent on the AlPO₄(KH550) loading. The addition of AlPO₄(KH550) into CE resin changes the thermodegradation mechanism (mainly at the temperature lower than 450°C) and degradation process from two steps to three steps. Comparing with CE resin, AlPO₄(KH550)/CE composites have lower initial degradation temperature and greatly higher char yield. Besides, for each thermodegradation step, the more the AlPO₄ content, the smaller the activation energy value is. All reasons leading to these outcomes are investigated intensively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009