In this literature, we report preparation and characterization of novel polymer alloy which has both high heat resistant and low CTE. This alloy was prepared by melt mixing of two resins, Bismaleimide diphenyl methan(BMI) and 3,3'-(methylen-1,4-diphenylen)bis(3,4-dihydro-2H-1,3-benzoxazine) (P-d), and cured only 200°C/4h.The optimum molar ratio was examined from the view point of mechanical properties at the high temperature by using DVA, TGA and TMA. As a result polybenzyoxazine modified bismaleimide alloys showed higher T_g than each independent neat resin. This phenomenon suggests interaction between BMI and P-d and we try to analyze this by using monofunctional compounds. The resin consisting of BMI 1.0 vs. P-d 0.3 showed the most superior thermal properties with processability. This resin has T_g of 310°C, T_d10 of over 400°C and CTE of 48ppm/K which is lower than conventional epoxy resins 70ppm/K. DSC results suggest the reaction between BMI and P-d. The reactivity between phenolic hydroxyl group and double bond of maleimide was confi rmed by model reaction using phenol, N-phenyl maleimide and accelerator. And the reactivity between Mannich hydroxyl group of poly benzoxazine and double bond of bismaleimide was suggested.

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Novel polymer alloys were prepared by thermal treatment up to 240 °C of the mixture of high molecular weight benzoxazine and typical bismaleimide, N,N'- (4,4'-methylenediphenylene)dimaleimide. Polymerization behaviors of the blend mixtures were investigated using IR and DSC, which showed that obtained polymer alloys are AB-co-crosslinked polymer networks through the formation of ether linkage between the hydroxyl group of polybenzoxazine and the double bond of bismaleimide by the heat treatment. Viscoelastic analysis measurement exhibited that the polymer alloys have much higher glass transition temperatures than those of homopolymers. The thermal stability of polymer alloys was examined by TGA. The initial degradation temperature increased with the increase of bismaleimide content. Char yield of polymer alloys at 850 °C was higher than that of each homopolymer.

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Novel fluorinated organic－inorganic hybrid polymers, poly (methylmethacrylate-co-methacryroxypropyl (trifl uoropropyl-T₈-silsesquioxane))s [poly(MMA-co-7F-T₈-MMA)], were prepared from fl uorinated polyhedral oligomeric silsesquioxane (F-POSS) derivative monomer aiming for the application for surface modifi cation of polymeric materials. A blend material composed of poly (MMA-co-7F-T₈-MMA), a multi-functional acrylic monomer and radical photo initiator was cured by ultraviolet radiation. The resulting polymer films were analyzed by contact angle measurement, X-ray photoelectron spectroscopy, atomic force microscopy and field emission scanning electron microscopy. These analyses revealed that the F-POSS was preferentially populated at the air/polymer interface and that the outermost layer of the fi lm was almost completely covered by the F-POSS side-chains. This was mainly due to the low surface free energy and environmental stability of the F-POSS moiety.

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The heat resistance and mechanical properties of the alcohol-liquefied wood-based epoxy resins were studied in relation to the wood-liquefi ed solvent type. The wood-liquefi ed solvents were polyethylene glycol (PEG) as the aliphatic alcohol and bisphenol-A ethylene oxide adduct (BPAEO) as the aromatic alcohol. BPAEO was better than PEG as the woodliquefi ed solvent. The heat resistance and the tensile properties of the BPAEO-liquefi ed wood-based epoxy resin were higher than that of the PEG-liquefi ed one. The aromatic structure of the wood-liquefi ed solvent resulted in the high heat resistance and tensile properties of the wood-based epoxy resins. The glass transition temperatures and flexural properties were improved with increasing the biomass content in the BPAEO-liquefi ed wood-based epoxy resins.

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Power semiconductor devices are key devices for carbon dioxide reduction technology. Here, the author focuses on the power semiconductor device module of automotive electronics fi eld holding more than 50% of the power device market and introduce the optimum properties and gives an account of the examples for high heat resistant polymer materials applicable to the future power module.

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