Polylactide stereocomplex bearing vinyl groups at chain ends prepared by allyl alcohol, malic acid, and citric acid

Abstract

In order to develop functional polymers using polylactide (PLA), it has been paid attention to use various initiators for ring-opening polymerization, because the polymer backbone could not be modified if a stereocomplex formation was applied. Herein, we prepared a novel class of PLA stereocomplex with vinyl groups at chain ends, using allyl alcohol, malic acid, and citric acids. The initiators, triallyl citrate (TACA), diallyl malic acid (DAMA), and allyl alcohol (Alc), indicated that their different initiation efficiencies, depending on the number of the allyl terminated arms, influenced on their molecular weights of the polymers. The molecular weight of linear PLA-TACA reached 3000–5000 g/mol and formed the PLA stereocomplex. The thermal properties of the obtained PLAs were analyzed by Tm, Tg and ΔHm, resulting in the improvement of thermal properties by changing the number of allyl groups. This study suggested that it is possible to do further chemical modification with double bonds at chain ends of these PLA stereocomplexes.