硅烷化改性MCM-41负载戊二酸锌催化CO2与环氧丙烷共聚制备可降解材料

以三甲基氯硅烷(TMCS)为硅烷化试剂,对MCM-41分子筛进行表面改性处理,并以此为载体制备负载型戊二酸锌催化剂(ZnGA/TMCS-MCM-41);采用红外光谱、氮气吸附-脱附和X射线衍射等分析手段对催化剂进行表征,结果表明:三甲基氯硅烷基团被成功接枝到MCM-41分子筛表面,形成比表面积略低的硅烷化MCM-41载体,但其骨架未被破坏,负载活性物质过程中,戊二酸锌能以更小的粒径均匀分散到载体的表面;聚合反应实验表明,与单纯戊二锌催化剂相比,ZnGA/TMCS-MCM-41催化剂对CO2与环氧丙烷(PO)的共聚反应显示出更高的催化效率和更快的反应速度,在反应34 h后催化效率达到86.3 g聚合物/g ZnGA;红外光谱和核磁分析表明所得共聚产物中碳酸酯结构含量大于95.8%。

Preparation of degradable material by copolymerization between CO2 and propylene oxide using zinc gultarate supported on silylated-MCM-41

Mesoporous molecular sieve MCM-41 was modified by using trimethylchlorosilane(TMCS)as a silanized agent,and TMCS-MCM-41 supported zinc glutarate catalyst(ZnGA/TMCS-MCM-41)was prepared and characterized by low temperature nitrogen adsorption-desorption technique,Fourier-transform infrared spectroscopy and X-ray diffraction.The results indicated that TMCS functional group was successfully grafted to the surface of the molecular sieve forming the silanized MCM-41 supports with slightly smaller surface area but the frameworks of the molecular sieve were not destroyed.ZnGA can be highly dispersed on the surface of supporters at small size during loading.Much higher catalytic efficiency and faster reaction rate were acquired in copolymerization of CO₂ and propylene oxide(PO)by the catalyzed of ZnGA/TMCS-MCM-41 system than pure ZnGA,with catalytic efficiency at 86.3 g polymers per gram ZnGA after 34 hours reaction.More than 95.8% of carbonate content of poly propylene carbonate(PPC)copolymers was confirmed by structural analysis via infrared spectroscopy and ¹HNMR.