双金属氰化络合物催化环氧丙烷和邻苯二甲酸酐共聚

采用双金属氰化络合物 (DMC)催化环氧丙烷 (PO)和邻苯二甲酸酐 (PA)共聚 ,探讨了共聚合特征 ,并用IR、1 H NMR和GPC对共聚物的结构和分子量进行了表征 .发现DMC催化剂对该共聚反应速度快 ,转化率高 ,是该反应的有效催化剂 ,催化剂浓度为 6 0mg kg时 ,90℃下 ,以THF作溶剂共聚反应 3h ,转化率可达94 0 % .聚合速度甚至比DMC催化PO均聚还快 .该共聚反应可在多种溶剂中进行 ,极性溶剂更有利于共聚合 ,溶液聚合温度比本体共聚低 ,合适的溶液共聚温度在 90～ 10 0℃之间 .共聚产物的分子量受催化剂用量、反应温度和体系中水份含量的影响 ,数均分子量在数百至数千之间 .考察该共聚体系的动力学表明 ,该共聚反应速率对单体浓度呈一级关系

RING-OPENING COPOLYMERIZATION OF PHTHALIC ANHYDRIDE WITH PROPYLENE OXIDE BY DOUBLE-METAL CYANIDE

Ring-opening copolymerization of phthalic anhydride (PA) with propylene oxide (PO) was successfully carried out by using double-metal cyanide (DMC).The characteristics of the copolymerization were presented and discussed.The structure of the copolymer was characterized with IR and 1H-NMR.The number-average molecular weight (M n) and molecular weight distribution of the copolymer were measured by GPC.The results showed that DMC was a highly active catalyst for the copolymerization of PA and PO,giving high yield with a rate much higher than that of PO homopolymerization with the same catalyst at a low catalyst level of 60?mg/kg.This copolymerization can be also carried out in many organic solvents,and it was easier to be carried out in polar solvents such as THF and acetone than in non-polar solvents such as ether and cyclohexane.The proper temperature for reactions carried out in solutions was in the range of 90～100℃.That was lower than the temperature range for bulk-copolymerization.The M n was affected by the catalyst level,reaction temperature and trace water.M n was in a range of 2500～4000 under firm polymerization conditions by removing trace water and other impurities.The kinetics of the copolymerization was also studied.The results indicated a first order relationship between the copolymerization rate and the monomer concentration.