Preparation of modified polylactic acid fiber containing anti-hydrolysis agents

Polylactic acid (PLA) is a promising alternative to petroleum-based polymers due to its biodegradability. However, its low mechanical properties in the presence of moisture are a challenge for textile applications. In this study, we investigated the effects of two anti-hydrolysis agents, an epoxy-based agent (ADR) and an aromatic carbodiimide-based agent (ZIKA), on the mechanical properties and hydrolysis resistance of PLA fibers. A melt-spinning process was used to prepare anti-hydrolysis fibers by adding 0.3 and 0.5 wt% of ADR and ZIKA to PLA. The topology of ADR/PLA and ZIKA/PLA was determined by Fourier transform infrared spectroscopy (FT-IR). Analysis of the compound chip revealed that ADR formed a branched chain in PLA, while ZIKA produced a linear molecular structure. The hydrolysis resistance of the fibers was evaluated by analyzing their crystallinity, hydrothermal shrinkage behavior, morphology, and tensile strength. ZIKA/PLA fibers showed higher orientation and crystallinity than ADR/PLA fibers. After hydrolysis, the tensile strength of ADR 0.5%/PLA fibers decreased by 31%, while that of ZIKA 0.5%/PLA fibers decreased by only 5% due to the linear molecular structure of ZIKA/PLA. Our findings indicate that ZIKA is more effective than ADR in producing hydrolysis-resistant PLA fibers with high crystallinity, orientation, and mechanical durability.