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Information × Registration Number 0213U002010, 0110U003467 , R & D reports Title Sol-gel synthesis of epoxy-siloxane composites and their resistance to thermooxidative destruction popup.stage_title Head Mykhalchuk Volodymyr Mykhajlovych, Registration Date 03-01-2013 Organization Donetsk National University popup.description2 Object of investigation - epoxy polymers and epoxy-silica composites of cationic polymerization and anhydride curing. The goal of the current stage of research is investigation of epoxy-silica composites' properties. Methods - dynamic mechanical analysis, thermomechanical analysis, differential thermomechanical analysis, differential scanning calorimetry, derivatography. Epoxy-silica composites of cationic polymerization and anhydride curing based on diglycidyl ether of dicyclohexylolpropane or triepoxide of 1,1-dimethylol-3-cyclohexene with silica content 0,5-3 wt.% were synthesized via the sol-gel method. Thermal stability and other properties of such polymers were investigated. High-dispersed silica filler presence in epoxy polymers of cationic polymerization and anhydride curing causes formation of structure which is non uniform by segmental mobility. General decrease of the composites' network density, growth of the molecular mass of chains between junctions, shifting of ?-relaxation transition to lower temperatures also take place in composites compared to corresponding polymers. Formation of polymer network with minimal amount of topological defects and network density parameters which are equal to theoretical values takes place in the case of Cr(acac)3 using as a catalyst of anhydride curing of epoxy, independently of epoxy resin type and presence of silica component in the system. Irrespective of type of epoxy resin used the least resistance to destruction was found for polymers and composites cured in the presence of Ni(acac)2. Polymers and composites obtained using Cr(acac)3 are the most resistant to thermooxidative destruction. Epoxy-silica composites of cationic polymerization are highly resistant to thermooxidative processes at SiO2 concentration in system less then 1,5 wt.%. At such filler content the effect of small additions take place. This effect causes polymers' thermostability increase, reduce of maximal rates of thermal degradation and high-temperature oxidation. The results of investigation can be proposed for development of novel polymer materials in Ukrainian state research institute of plastic masses, The Institute of Macromolecular chemistry of the NAS of Ukraine, Antonov ASTC etc. Product Description popup.authors Жильцова Світлана Віталіївна (без оплати) Леонова Наталя Геннадіївна (без оплати) Лига Рита Іванівна Лугова Ганна Олександрівна Михальчук Володимир Михайлович popup.nrat_date 2020-04-02 Close