多金属氰化络合物催化环氧丙烷的聚合

用多金属氰化络合物(MMC)催化环氧丙烷开环均聚,考察了酸及起始剂对聚合诱导期的影响,以及转化单体/起始剂摩尔比、酸用量、加料方式及催化剂等对聚合物相对分子质量及其分布的影响。并用FTIR、1HNMR、SEC-MALLS对聚合产物结构进行了表征。结果表明,以MMC为催化剂,在w(H2SO4)<5×10-5、温度130℃、连续加料、w(MMC)>1×10-4时,所合成聚醚相对分子质量分布较窄(Mw/Mn=1.1~1.2),且相对分子质量可控;FTIR、1HNMR及SEC-MALLS分析结果表明,所合成聚醚具有预期结构。实验发现,聚合反应体系只存在一种活性中心,其机理可能为配位阳离子聚合。

Polymerization of Propylene Oxide by Using Multi-metal Cyanide Based Catalyst

Polymerization of propylene oxide(PO) was carried out by using a multi-metal cyanide based catalyst.The molecular weight of the polymer synthesized can be effectively controlled by monomer/initiator molar ratio(M/I).The result showed that the relative macromolecular mass of the polyether possesses a narrow relative molecular mass distribution(1.1~1.2) under the condition of sulfuric acid concentration(w(H2SO4)<5×10-5)with a continuous monomer feeding process and a higher catalyst concentration(w(MMC)>1×10-4) at 130 ℃.The macromolecular structure of the polyether was characterized by FTIR,SEC-MALLS and 1HNMR,and it is suggested that the polymerization is probable to follow a coordination cation mechanism.