Lee, SH Kim, SH Kim, YH Han, YK 2024-01-21T10:45:38Z 2024-01-21T10:45:38Z 2021-09-05 2002-04 1598-5032 https://pubs.kist.re.kr/handle/201004/139662 Poly(ethylene oxide)/polylatide/poly(ethylene oxide) (PEO/PL/PEO) tri-block copolymers, which each block is connected by ester bond, were synthesized by coupling reaction of PL with PEO in the presence of pyridine. PL/PEO/PL tri-block copolymer was synthesized by ring opening polymerization of L-lactide initiated by PEO in the presence of stannous octoate. Degradation behavior of the copolymers was investigated in a pH 7.4 phosphate buffer saline (PBS) at 37 +/- 1degreesC. Gel permeation chromatography (GPC) and H-1-nuclear magnetic resonance (NMR) were used to monitor the change of mass loss, molecular weight and composition of copolymers. In hydrolytic degradation, the PEO/PL/PEO tri-block copolymer with high PEO contents affected the increase of its mass loss. and resulted in the decrease of its molecular weight as well as PEO composition. However, when PL/PEO/PL and PEO/PL/PEO tri-block copolymers had similar PEO contents, PEO/PL/PEO decreased faster in molecular weight and PEO composition than PL/PEO/PL. English SPRINGER PLA/PEO/PLA TRIBLOCK COPOLYMERS DRUG-DELIVERY SYSTEMS HYDROLYTIC DEGRADATION LACTIDE Synthesis and degradation Behaviors of PEO/PL/PEO tri-block copolymers Article 10.1007/BF03218295 1 MACROMOLECULAR RESEARCH, v.10, no.2, pp.85 - 90 MACROMOLECULAR RESEARCH 10 2 85 90 scie scopus kci ART001183828 000175376000007 2-s2.0-0038576210 Polymer Science Polymer Science Article PLA/PEO/PLA TRIBLOCK COPOLYMERS DRUG-DELIVERY SYSTEMS HYDROLYTIC DEGRADATION LACTIDE polylactide poly(ethylene oxide) biodegradable polymer tri-block copolymer hydrolytic degradation