A comparative study on in vitro degradation behavior of PLLA-based copolymer monofilaments

Publication date: Available online 7 November 2018Source: Polymer Degradation and StabilityAuthor(s): Daokun Shi, Yahong Kang, Guoyi Zhang, Chenguang Gao, Wei Lu, Caihong Yang, Hua Zou, Hongyan JiangAbstractThree kinds of high molecular weight polymers were synthesized by ring-opening polymerization with various monomer feeding ratios (named as PLLA, PLCL 95/5 and PLGC 80/15/5, respectively). Then oriented monofilament was produced through melt-extrusion and tensile orientation based on each kind of polymer. In vitro degradation properties of the monofilaments were studied over a range of degradation time from 1 to 21 days at 60 °C by using SEM, GPC, DSC, XRD and tensile test. Degradation results showed that the mass loss, Tg and morphology integrity of the PLLA monofilament basically remained unchanged, and partial degradation in amorphous region emerged with slight increase of crystallinity. For the PLCL 95/5 monofilament, the crystallinity was increased and the monofilament was fractured at 14 days accompanying with obvious decrease of the mass and Tm, indicating that most part of the amorphous region was degraded. Apparently, the PLGC 80/15/5 monofilament showed the fastest degradation rate with considerable mass loss and decrease of Tg. The amorphous region was degraded sharply in the early stage due to its good water absorbability and lower structural regularity, and the initially-formed crystalline region was degraded slowly later evidenced from the change of crysta...

Source: Polymer Degradation and Stability - November 8, 2018 Category: Chemistry Source Type: research