Influence of the Synthesis Conditions on the Structural and Thermal Properties of Poly( L- lactide)- b- Poly( ethylene glycol)- b- Poly( L- lactide)

Autor(es)

Trinca, Rafael Bergamo ^[1] ; Felisberti, Maria Isabel ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Chem, BR-13083970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Applied Polymer Science; v. 131, n. 13 JUL 5 2014.
• Citações Web of Science: 8

Resumo

The poly(l-lactide)-b-poly(ethylene glycol)-b-poly(l-lactide) block copolymers (PLLA-b-PEG-b-PLLA) were synthesized in a toluene solution by the ring-opening polymerization of 3,6-dimethyl-1,4-dioxan-2,5-dione (LLA) with PEG as a macroinitiator or by transterification from the homopolymers {[}polylactide and PEG]. Two polymerization conditions were adopted: method A, which used an equimolar catalyst/initiator molar ratio (1-5 wt %), and method B, which used a catalyst content commonly reported in the literature (<0.05 wt %). Method A was more efficient in producing copolymers with a higher yield and monomer conversion, whereas method B resulted in a mixture of the copolymer and homopolymers. The copolymers achieved high molar masses and even presenting similar global compositions, the molar mass distribution and thermal properties depends on the polymerization method. For instance, the suppression of the PEG block crystallization was more noticeable for copolymer A. An experimental design was used to qualify the influence of the catalyst and homopolymer amounts on the transreactions. The catalyst concentration was shown to be the most important factor. Therefore, the effectiveness of method A to produce copolymers was partly due to the transreactions. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40419. (AU)

• Processo FAPESP: 10/17804-7 - Compósitos poliméricos
• Beneficiário: Maria Isabel Felisberti
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 08/07157-4 - Síntese e caracterização dos copolímeros anfifílicos aleatórios e em bloco baseados em poli(etileno glicol) (PEG), poli(L-lactídeo) (PLLA) e poli(carbonato de trimetileno ) (PTMC).
• Beneficiário: Rafael Bergamo Trinca
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 10/02098-0 - Materiais poliméricos multicomponentes
• Beneficiário: Maria Isabel Felisberti
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/09479-1 - Poliuretanas segmentadas multicomponentes
• Beneficiário: Rafael Bergamo Trinca
• Modalidade de apoio: Bolsas no Brasil - Doutorado