介孔SBA-15负载磷钨酸催化四氢呋喃聚合的研究

摘要

以SBA-15为载体负载磷钨酸(HPW)，用于催化四氢呋喃(THF)开环聚合，采用在线反应红外分析仪(ReactIR)测定THF转化率，实验考察了HPW负载质量百分比、3-氨丙基三乙氧基硅烷(APTES)/SBA-15质量比和载体SBA-15孔径等因素对催化剂的催化性能和THF转化率的影响。结果表明：采用直接浸渍法负载HPW，HPW最优负载质量百分比为40%；将SBA-15进行氨基改性后负载HPW，最优APTES/SBA-15质量比为mAPTES/mSBA-15=0.0712，且通过氨基改性可有效改善催化剂的重复利用性能；当载体 SBA-15的比表面积较大时(853 m2⋅g-1)或孔径较大(比表面积较小498~585 m2⋅g-1)时，所制备的催化剂具有较高的催化效率、聚合产物平均分子量较大，催化剂的催化效率和聚合产物分子量随着孔径增大而增大。%A catalyst synthesized by loading phosphotungstic heteropolyacid on mesoporous silica material SBA-15 support was used in ring-opening polymerization of tetrahydrofuran (THF). The polymerization of THF was monitored in real-time by ReactIR. The effects of mass fraction of HPW, the mass ratio of 3-aminopropyl-triethoxysilane (APTES) to SBA-15, and the pore diameter of SBA-15 on catalytic performance and the conversion of THF were investigated. It was found that the supported catalyst HPW/SBA-15 prepared by impregnation with 40% mass fraction of HPW exhibits the highest activity. The amino-functionalized SBA-15 can effectively improve the catalytic performance of catalyst HPW/NH2-SBA-15 for repeated use in THF polymerization. And the catalyst HPW/NH2-SBA-15 has the highest activity when the mass ratio of mAPTES/mSBA-15=0.0712. It shows good catalytic performance. Its PTHF product has higher molecular weight when SBA-15 has larger specific surface area or larger pore sizes (specific surface area=498~585 m2⋅g-1). Also, the catalytic performance of catalysts and the molecular weight of PTHF product increase with the pore size of SBA-15.