End Functionalization by Ring Opening Polymerization: Influence of Reaction Conditions on the Synthesis of End Functionalized Poly(lactic Acid)

• Autor(a) principal: Icart,Luis P.
• Data de Publicação: 2018
• Outros Autores: Fernandes,Edson, Agüero,Lissette, Cuesta,Maelia Z., Silva,Dionisio Z., Rodríguez-Fernández,Daniel E., Souza Jr.,Fernando G., Lima,Luis Maurício T. R., Dias,Marcos L.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532018000100099
• topic: poly(lactic acid); ring opening polymerization; end group functionalized PLA; experimental design

In this paper, chemical functionalization of poly(lactic acid) (PLA) was carried out by using of salicyl aldehyde (SAl) and salicylic acid (SAc) as co-initiators of ring opening polymerization (ROP). Two factorial designs (22) were performed to evaluate the effects of the lactide/catalyst and co-initiator/catalyst molar ratios on the content of aldehyde or carboxylic acid end groups, thermal properties and molecular weight (Mw) of PLA. Tin(II) 2-ethylhexanoate was used as a catalyst. The co-initiator/catalyst molar ratio has a statistically significant influence on the polymer functionalization. The highest co-initiator/catalyst molar ratio of 12/1 allows the best aldehyde or carboxylic acid functionalization, independent on the lactide/catalyst molar ratio. On the other hand, the used lactide/catalyst and co-initiator/catalyst molar ratios did not show a statistically significant influence on the polymer thermal properties. Besides, co-initiator/catalyst molar ratio has a statistically significant influence on the polymer molecular weight. So, the highest co-initiator/catalyst molar ratio used (12/1) in combination with the highest lactide/catalyst ratio (125/1) produced functionalized PLA with higher molecular weights.