二氧化硅负载磷钨酸催化β-蒎烯阳离子聚合反应

Silica-supported Phosphotungstic Acid as Catalyst for β-Pinene Polymerization

采用浸渍法制备二氧化硅负载磷钨酸催化剂,催化β-蒎烯阳离子聚合合成β-萜烯树脂.运用红外光谱、X射线衍射、透射电镜、比表面积和孔径测定、核磁共振氢谱和凝胶渗透色谱等测试技术对催化剂和聚合产物的结构进行了表征.考察了磷钨酸的负载量、催化剂用量、反应温度、反应时间、原料浓度等因素对产物收率的影响,确定了最佳反应条件:催化剂负载量为60%,用量为0.6 g,反应温度为-20℃,反应时间为1 h,β-蒎烯的用量为3 ml,1,2-二氯乙烷用量溶剂为7ml时,β-蒎烯树脂收率可达84.8%,数均分子量在1200左右,分子量分布指数为1.72.

The silica-supported phosphotungstic acid catalysts were prepared by impregnation method, and their catalytic performance on β-pinene cationic polymerization to obtain poly（β-pinene）s was also investigated. The catalysts and polymers were characterized by FT-IR spectra, X-ray diffraction, transmission electron microscopy, Brunauer - Emmett - Teller method, 1H-NMR spectra, and gel permeation chromatograph. The effect of catalyst loading amount, dosage of catalyst, polymerization temperature, polymeriza- tion time, and monomer concentration on the yield of polymers was studies. The polymerization conditions were optimized as follows： 60 wt% of loading amount; 0.6 g of catalyst; -20℃ of polymerization temperature; lh of polymerization time; 3 ml of β-pinene; 7ml of 1,2-dichloroethane. Under these conditions, the polymer yield was up to 84.8%, the number-average molecular weight was about 1200 and the polydispersi- ty was 1.72.