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Synthesis of Poly[(lactic acid)‐ alt ‐ or co ‐(( S )‐aspartic acid)] from (3 S ,6 R , S )‐3‐[(Benzyloxycarbonyl)methyl]‐6‐methylmorpholine‐2,5‐dione
Author(s) -
Feng Yakai,
Klee Doris,
Höcker Hartwig
Publication year - 2002
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20020401)203:5/6<819::aid-macp819>3.0.co;2-f
Subject(s) - copolymer , lactic acid , polymer chemistry , catalysis , chemistry , lactide , polymerization , glass transition , aspartic acid , ring opening polymerization , polymer , biodegradable polymer , organic chemistry , amino acid , biochemistry , bacteria , biology , genetics
Poly[(lactic acid)‐ alt ‐(( S )‐ β ‐benzyl aspartate)] was synthesized via ring‐opening polymerization of (3 S ,6 R , S )‐3‐[(benzyloxycarbonyl)methyl]‐6‐methylmorpholine‐2,5‐dione (Cyclo[Lac‐Asp(OBzl)]) in the presence of Sn(oct) 2 as a catalyst at 140°C. Poly[(lactic acid)‐ co ‐(( S )‐ β ‐benzyl aspartate)] was obtained via copolymerization of Cyclo[Lac‐Asp(OBzl)] with D , L ‐lactide under the same conditions. The protective benzyl groups of these copolymers were completely removed by catalytic hydrogenation to give biodegradable poly[lactide‐ alt‐ or co ‐(( S )‐aspartic acid)]. Poly[lactide‐ alt‐ and co ‐(( S )‐aspartic acid)] are amorphous polymers. The glass‐transition temperature of the copolymers after deprotection is higher than that of copolymers before deprotection.