苄醇存在下脂肪叔胺催化内酯开环聚合

为研究脂肪叔胺结构对内酯开环聚合规律的影响,以三乙胺( TEA)、N,N,N′,N′-四甲基乙二胺(TMEDA)、N,N,N′,N″,N″-五甲基二亚乙基三胺(PM DTA)3种不同结构的叔胺催化碳酸三亚甲基酯(TMC)和左旋丙交酯( L-LA)开环聚合.结果显示,在55℃的THF溶液中,以苄醇为引发剂,3种叔胺均能催...

RING-OPENING POLYMERIZATION OF LACTONE IN THE PRESENCE OF BENZYL ALCOHOL CATALYZED BY ALIPHATIC TERTIARY AMINE

In order to study the structure and the catalytic activity of aliphatic tertiary amines,the ring-opening polymerizations of trimethylene carbonate(TMC) and L-lactide(L-LA) were catalyzed by aliphatic tertiary amines,including triethylamine(TEA),N,N,N′,N′-tetramethylethylenediamine(TMEDA),1,1,4,7,7-pentamethyldiethylenetriamine(PMDTA) and 4-(dimethylamino)pyridine(DMAP),using benzyl alcohol as initiator in THF at 55℃.Studies revealed the catalytic activity of these tertiary amines was increased according to the order:TEA < TMEDA≈PMDTA < DMAP.The relationships of polymer molecular weight with the conversion of monomer were linear,which were consistent with a living polymerization character.Finally,the plausible polymerization pathway was through an alcohol-activating mechanism.Aliphatic tertiary amines which were abundant in source and cheap in price were suitable for catalyzing the ring-opening bulk polymerization of lactone in low temperature because of their low boiling point,being liquid under ordinary conditions and being easy to get rid of.