MQ silicone resins were prepared through hydrolytic condensation of ethyl polysilicate or tetraethoxysilane and hexamethyl disiloxane. The unit ratio of the MQ resins was determined by Si-29-NMR. The relationship of t...MQ silicone resins were prepared through hydrolytic condensation of ethyl polysilicate or tetraethoxysilane and hexamethyl disiloxane. The unit ratio of the MQ resins was determined by Si-29-NMR. The relationship of the unit ratio of the product resins with that in the feed was studied. When the reaction was catalyzed by aqueous hydrochloric acid, and the unit ratio of M to Q in the feed was more than 1, the unit ratio of the product was usually lower than that of the feed. The MQ silicon with an unit ratio of M/Q > 2 could not be obtained. However, if the reaction was catalyzed by concentrated sulfuric acid and the reverse hydrolysis process was employed, MQ silicone resin with very high M/Q ratio was successfully prepared.展开更多
A novel poly(ether imide)s containing phthalazinone and isopropyl moieties derived from 2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl]-phthalazin-1-one and bisphenol-A diphthalic anhydride was synthesized by one-step ...A novel poly(ether imide)s containing phthalazinone and isopropyl moieties derived from 2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl]-phthalazin-1-one and bisphenol-A diphthalic anhydride was synthesized by one-step solution condensation polymerization in nr-cresol. The polymer was characterized by FTIR, NMR, molecular weights, glass transition temperature, thermal degradation temperature and WAXD.展开更多
The hydrolytic co-condensation of hydrophobic phenyltriethoxysilane （PTES） and hydrophilic γ-aminopropyltriethoxysilane （APS） was investigated in toluene and water by using hydrochloric acid （HCl） catalyst. A s...The hydrolytic co-condensation of hydrophobic phenyltriethoxysilane （PTES） and hydrophilic γ-aminopropyltriethoxysilane （APS） was investigated in toluene and water by using hydrochloric acid （HCl） catalyst. A soluble and meltable poly（aminopropyl/phenylsilsesquioxane） （PAPSQ） was formed by controlling HCl amounts, APS/PTES molar ratios, water/silane molar ratios （Rw/si）, organic co-solvents and re-equilibration steps as well. The compositions of PAPSQ bearing aminopropyl and phenyl groups with the capping of trimethylsilyl group were confirmed by element analysis, fourier-transform infrared spectroscopy （FT-IR）, nuclear magnetic resonance （NMR） and thermogravimetric analysis （TGA）. Differential scanning calorimetry （DSC） was employed to characterize the melting behavior of the product. PAPSQ can be easily employed as functional molecular building blocks for the synthesis of diverse and novel inorganic-organic materials.展开更多
文摘MQ silicone resins were prepared through hydrolytic condensation of ethyl polysilicate or tetraethoxysilane and hexamethyl disiloxane. The unit ratio of the MQ resins was determined by Si-29-NMR. The relationship of the unit ratio of the product resins with that in the feed was studied. When the reaction was catalyzed by aqueous hydrochloric acid, and the unit ratio of M to Q in the feed was more than 1, the unit ratio of the product was usually lower than that of the feed. The MQ silicon with an unit ratio of M/Q > 2 could not be obtained. However, if the reaction was catalyzed by concentrated sulfuric acid and the reverse hydrolysis process was employed, MQ silicone resin with very high M/Q ratio was successfully prepared.
文摘A novel poly(ether imide)s containing phthalazinone and isopropyl moieties derived from 2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl]-phthalazin-1-one and bisphenol-A diphthalic anhydride was synthesized by one-step solution condensation polymerization in nr-cresol. The polymer was characterized by FTIR, NMR, molecular weights, glass transition temperature, thermal degradation temperature and WAXD.
基金Funded by the National Natural Science Foundation of China (No.20574020, No.10676009)
文摘The hydrolytic co-condensation of hydrophobic phenyltriethoxysilane （PTES） and hydrophilic γ-aminopropyltriethoxysilane （APS） was investigated in toluene and water by using hydrochloric acid （HCl） catalyst. A soluble and meltable poly（aminopropyl/phenylsilsesquioxane） （PAPSQ） was formed by controlling HCl amounts, APS/PTES molar ratios, water/silane molar ratios （Rw/si）, organic co-solvents and re-equilibration steps as well. The compositions of PAPSQ bearing aminopropyl and phenyl groups with the capping of trimethylsilyl group were confirmed by element analysis, fourier-transform infrared spectroscopy （FT-IR）, nuclear magnetic resonance （NMR） and thermogravimetric analysis （TGA）. Differential scanning calorimetry （DSC） was employed to characterize the melting behavior of the product. PAPSQ can be easily employed as functional molecular building blocks for the synthesis of diverse and novel inorganic-organic materials.
