Polyethercarbonate-silica nanocomposites synthesized by copolymerization of allyl glycidyl ether with CO_2 followed by sol-gel process

摘要

The catalyst system consisting of Y(CF_3CO_2)_3,Zn(Et)_2,and pyrogallol in teh solvent of 1,3-dioxolane was found to be effective fo rthe copolymerization of allyl glycidyl ethr withcarbon dioxide at 60 deg C and 400 psi.the IR,~1H-NMr,and ~13C-NMR spectra as well as the element analysis indicated that the resulting copolymer was an alternting polyethercarbonate with the crbonate content higher than 97.5(percent).The resulting polyethercarbonate could react with 30-(trimethoxysilyl)propyl mehtacrylate via a free radical reaction to generate the alkoxysilane-containing copolymer precursors that were used in teh subswequent sol-gel process to result in teh polyethercarbonate-silica nanocomposite.The generated nanocomposite was characterized by ~(13)C-NMr,~(29)Si-NMR,SEM,SDC,TGA,ESCA,and UV-Vis.The mechanical properties were also measured.A good compatibility between polyethercarbonate and silica and a SiO_2 network with silica particles less than 100 nm in the nanocomposite were observed.Both the thermal and mechanical properties of the resulting polyethercarbonate-silica nanocomposite were found to enhance with silica content.Teh opticla transparency of the gnerated nanocomposite was comparable to that of the based polyethercarbonte.