Spinnability and characterization of poly(D-lactic acid)-blended poly(L-lactic acid) filament yarns

Abstract

Conventional textiles are produced mainly by petroleum-based polymeric materials, which are not biodegradable, cause serious pollution, and waste problems. Especially, poly(ethylene terephthalate) is the most used thermoplastic polyester in various textile applications. At this point, poly(lactic acid) (PLA), a biodegradable polyester, stands out forward with its unique properties. PLA is derived from renewable sources such as corn, sugar cane, and so on. In this study, poly(D-lactic acid) (PDLA) was blended to poly(L-lactic acid) (PLLA) to reduce its highly crystalline morphology and rigidity. Introduction of PDLA would be expected to speed up its degradation by decreasing the amount of crystalline regions. PDLA was compounded into PLLA in amounts of 3, 6, and 9 wt%. First, PDLA-blended PLLA compounds were produced, and then successfully spun/drawn into filament yarns by using a pilot-scale melt spinning equipment. The compounds and the filament yarns were characterized by SEM, DSC, viscosity, carboxyl number, tenacity, elongation at break, unevenness, and shrinkage. Results showed that the amount of crystalline regions was decreased with increasing PDLA amount in both compounds and filament yarns. On the other hand, PDLA blending enhanced the rigidity of filament yarns by increasing their elongation at break.