窄分子量分布端羟基环氧乙烷-四氢呋喃共聚醚的合成及表征

用三氟化硼乙醚络合物(BF3.OEt2)为催化剂,乙二醇(EG)为起始剂,甲苯作溶剂,通过阳离子开环聚合制备出了窄分子量分布(w/n<1.3)的端羟基环氧乙烷-四氢呋喃(TEO)共聚醚,探讨了聚合温度、时间、反应介质、加料方式、起始剂及单体配比对分子量及其分布的影响,采用凝胶渗透色谱-多角度激光散射联用仪(SEC-MALLS)对其分子量及分布进行准确的测定,并用IR和1HNMR对共聚醚结构进行了表征。研究表明:有EG存在时,采用一次加料的方式,以甲苯为溶剂,温度为0℃,单体配比为11,∶反应时间为5 h的条件下制得的共聚醚具有分子量分布较窄的特点。

Synthesis and characterization of hydroxy terminated TEO copolyether with narrow molecular weight distribution

Narrow molecular weight distribution(w/n<1.3)of hydroxy-interminated copolyether consisting of tetrahydrofuran(THF) and ethylene oxide(EO) segment was synthesized by cationic ring-opening polymerization with boron-trifuoride ethylether complex(BF3·OEt2)as the catalyst,ethylene glycol(EG) as initiator and toluene as solvent.The effect of the polymerization temperature,time,reaction media,feeding process,molar ratio of THF/EO on its molecular weight and molecular weight distribution were studied by size-exclusion chromatography and multiangle laser light scattering(SEC-MALLS).The macromolecular structure of copolyether was also characterized by IR and 1H-NMR.It was found that copolyether with the narrowest molecular weight distribution can be synthesized at 0 ℃ for 5 hours using EG as intiator and toluene as solvent.The monomers were fed in one batch and the monomer ratio was determined as 1∶1(mole ratio).