Tudy On Synthesis Of Epoxy Resin Modified With Polysiloxane

Epoxy resin has excellent mechanical properties, electrical properties, adhesiveproperties, heat resistance, solvent resistance, easy molding processing advantages, etc. But inits cured three-dimensional network structure, there are some defects limit its furtherapplication, such as lack sliding of molecular chain, low bond-energy of carbon-carbon bondsand carbon-oxygen bond, high surface free energy, great inner stress, brittleness because withsome hydroxyl. Polysiloxane has good thermal stability, oxidation resistance, low surfaceenergy, high dielectric strength, weatherability, water repellency, low temperature flexibility,etc. We can improve the toughness of epoxy resin, temperature resistance, water tolerance andother properties of epoxy resin through modified by polysiloxane. Polysiloxane modifiedepoxy resin is becoming the research focus of the modified epoxy resin in recent years.In this paper, the terminal hydrogen silicone oil, allyl glycidyl ether,4-vinyl-1,2-epoxycyclohexane have been used synthetic polysiloxane epoxy resin by hydrosilylation reaction.We have studied the impact of reaction of monomer ratio, catalyst amount, reactiontemperature, the polymerization inhibitor and reaction time on the synthesis of polysiloxaneepoxy. The polysiloxane epoxy has been analyzed by fourier transform infraredspectroscopy（FT-IR）, gel permeation chromatography （GPC）, nuclearmagnetic resonance（¹H-NMR）, epoxy equivalent analyze test characterization. By analyzed the formula structure,equivalent weight, active hydrogen conversion rate, size and distribution of molecular weightof the polysiloxane epoxy, we have obtained the best conditions of the synthesis ofpolysiloxane epoxy:（1）The reaction conditions of get better traits polysiloxane epoxy by hydrosilylationreaction through terminal hydrogen silicone oil and allyl glycidyl ether are as follows:â‘ THF solution of chloroplatinic acid of （H₂PtCl₆6H₂O） as the catalyst, the dosage is0.01%⁰.02%of the quality of the reactants; Tydroxyanisole is adopted as an inhibitor, and ifthe dosage was controlled around0.01%, we can get better color reaction product.â‘¡The conversion rate of the active hydrogen in the terminal hydrogen silicone oil was high underthe follow conditions: the molar ratio of C=C/Si-H in AGE （allyl glycidyl ether） andterminal hydrogen silicone oil C=C/Si-H was4.38:1; the reaction temperature was85℃;the reaction time was controlled in about6h.（2）The reaction conditions of get better modified epoxy resin by hydrosilylation reactionthrough terminal hydrogen silicone oil,4-vinyl-1and2-cyclohexene oxide are as follows:the reaction time was controlled in about8h; the reaction temperature was85℃;Chloroplatinic acid as the catalyst, the dosage is0.018%of the quality of the reactants; themolar ratio of C=C/Si-H in VCHO and terminal hydrogen silicone oil was4:1. Under theseconditions, the conversion rate of synthesized epoxy resin was high.The polysiloxane epoxy resin and Bisphenol A epoxy resin GELR-128was cured bydicyandiamide respectively. The cured products were analyzed by infrared spectroscopy andthermal gravimetric analysis. The results showed that the obtained polysiloxa-ne epoxy resin has good heat resistance and thermal stability.