端异氰酸酯基聚氨酯预聚体的合成及其应用研究

摘要

以甲苯二异氰酸酯( TDI)为改性剂,分别以聚乙二醇单甲醚( MPEG)、聚乙二醇( PEG)为基础物质,采用溶液聚合法分别合成了端异氰酸酯基聚乙二醇单甲醚( NCO-MPEG)、端异氰酸酯基聚氨酯预聚体( NCO-PUE)和乙醇封端的端异氰酸酯基聚氨酯预聚体( NCO-PUE-ET)。实验确定TDI与MPEG、 PEG以及NCO-PUE乙醇封端的反应时间分别为1.5 h、3.0 h和1.5 h,当反应物配比nTDI：nPEG=1.05：1时,聚合产物NCO-PUE的数均分子量达到3.55万； FTIR分析结果表明通过TDI与MPEG、PEG的加成反应将-NCO基团带到了聚氨酯预聚体分子链的末端,并且聚合产物NCO-MPEG被成功接枝到了聚二甲基硅氧烷( PDMS)弹性粒子表面；热重分析( TG)结果表明端异氰酸酯基聚氨酯预聚体的初始热分解温度均在350℃以上,完全能够满足下一步实验需要。%Using toluene diisocyanate ( TDI ) as modifier, polyethylene glycol ( PEG ) and polyethylene glycol monomethyl ether ( MPEG ) as basic material, polyethylene glycol monomethyl ether with terminal isocyanate group ( NCO-MPEG) , polyurethane prepolymer with terminal isocyanate group ( NCO-PUE) , ethanol blocking of polyurethane prepolymer with terminal isocyanate group ( NCO - PUE - ET ) were prepared by solution polymerization method. Experiment determined that the reaction time of MPEG and TDI, PEG and TDI, ethanol blocked NCO-PUE were 1. 5 h, 3 h, 1. 5 h. When the reactant ratio nTDI:nPEG=1. 05/1, NCO-PUE average molecular weight was about 35000. FTIR analysis results showed that -NCO groups were introduced into the chain-end of polyurethane prepolymers by addition reaction of TDI and MPEG or PEG, and product NCO-MPEG successfully grafted onto polydimethylsiloxane ( PDMS ) elastomeric particles surface; TG result showed that the initial thermal decomposition temperature of polyurethane prepolymer was above 350 ℃. It was able to meet the next experiment needs.