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The random copolymers of glutamic acid(LG)and aspartic acid(ASP),poly(LG-co-ASP),with designed compositions could be successfully synthesized via combination of N-carboxyanhydride ring opening copolymerization with debenzylation.Ring opening copolymerizations ofγ-benzyl-L-glutamate N-carboxyanhydride(BLG-NCA)andβ-benzyl-Laspartate N-carboxyanhydride(BLA-NCA)were carried out by using different amines including triethylamine(TEA),diethylamine,n-hexylamine(NHA),triphenylamine,diphenylamine or aniline as initiators.All the 6 amines were highly efficient to get well-defined poly(BLG-co-BLA)copolymers with designed compositions although the polymerizations proceeded via different mechanisms(normal amine mechanism or/and activated monomer mechanism),which are based on chemical structure of amines.The molecular weights of poly(BLG-co-BLA)copolymers could be mediated by both TEA concentration and polymerization time.Then,debenzylation of poly(BLG-co-BLA)copolymers was conducted to prepare the corresponding hydrophilic random copolymers of poly(LG-co-ASP)withα-subunit structure in ASP structural units.The contents of LG structural units in poly(LG-co-ASP)copolymers matched with those of BLG-NCA in NCA-monomer feeds in ring opening copolymerizations initiated by NHA or TEA and were closed to the theoretical line.The diblock copolymer of poly(BLG-b-BLA)could also be synthesized via living NCA ring opening copolymerization by sequential addition of BLGNCA and BLA-NCA.
The random copolymers of glutamic acid (LG) and aspartic acid (ASP), poly (LG-co-ASP), with designed compositions could be successfully synthesized via combination of N-carboxyanhydride ring opening copolymerization with debenzylation. Ring opening copolymerizations of γ-benzyl -L-glutamate N-carboxyanhydride (BLG-NCA) andβ-benzyl-Laspartate N-carboxyanhydride (BLA-NCA) were carried out by using different amines including triethylamine (TEA), diethylamine, n- hexylamine (NHA), triphenylamine, diphenylamine or aniline as initiators. All of these 6 amines were highly efficient to get well-defined poly (BLG-co-BLA) copolymers with designed compositions although the polymerizations proceeded via different mechanisms (normal amine mechanism or / and activated monomer mechanism), which are based on chemical structure of amines. molecular weight of poly (BLG-co-BLA) copolymers could be mediated by both TEA concentration and polymerization time. Chen, debenzylation of poly corresponding hydrophilic random copolymers of poly (LG-co-ASP) with α-subunit structures in ASP structural units. The contents of LG structural units in poly in ring opening copolymerization initiated by NHA or TEA and were closed to the theoretical line. The diblock copolymer of poly (BLG-b-BLA) could also be synthesized via living NCA ring opening copolymerization by sequential addition of BLGNCA and BLA-NCA.