活性炭负载磷钨酸催化合成聚四氢呋喃

Sythesis of Polytetrahydrofuran over Active Carbon-Supported Phosphotungstic Acid

活性炭为载体制备了负载型磷钨酸催化剂,研究其在环氧氯丙烷的引发作用下催化四氢呋喃开环聚合的反应工艺。考察了反应时间、反应温度、四氢呋喃与环氧氯丙烷的质量比、催化剂的活化温度及催化剂用量对收率的影响,并分析了催化剂活性降低的原因。研究表明,最优反应条件为:反应时间为4 h,反应温度为50℃,四氢呋喃与环氧氯丙烷的质量比为15∶1,催化剂活化温度250℃,催化剂用量8%(按四氢呋喃质量计算),在此条件下,聚四氢呋喃的收率为56.7%,平均分子量在2000～2200之间。催化剂重复使用6次,产品收率维持在50%左右,催化剂表面磷钨酸的质量损失量<1‰。

Phosphotungstic acid catalyst supported on active carbon was prepared and its catalytic performance was studied in the synthesis of polytetrahydrofuran（PTHF） with epichlorohydrin（ECH） as an initiator.The effects of reaction time,reaction temperature,mass ratio of ECH to THF,activation temperature of catalyst and amount of catalyst on the yield were investigated.The reason for the loss of catalytic activity was also analyzed.The results show that the optimal reaction conditions are as follows： reaction time 4 h;reaction temperature,50 ℃;mass ratio of THF to ECH 15∶1;activation temperature of catalyst,250 ℃ and amount of catalyst,8%（based on THF）.The yield of PTHF is 56.7%,and molecular weight of the product can be controlled between 2000 and 2200 under the optimum polymerization conditions.The yield is relatined at about 50% and the loss of phosphotungstic acid is less than 1‰ when the as-synthesized catalyst is repeatedly used for 6 times.