0
Article ? AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button. Tier 2 ? Original research — experimental, observational, or case-control study. Direct primary evidence. Environmental Sources Sign in to save

Crystallization behaviors of chain extended poly (lactic acid) modified with ST-NAB3 and its improved mechanical and thermal properties

Research Square (Research Square) 2024
Dongxing Dun, Min Zhu, Min Zhu, Hongfu Zhou, Jian Li, Jing Hu

Summary

Researchers modified poly(lactic acid) (PLA) with a styrene-acrylonitrile-glycidyl methacrylate chain extender (SAG) and an octamethylenedicarboxylic dibenzoylhydrazide nucleating agent (ST-NAB3) to improve its crystallization, mechanical properties, and thermal resistance as a biodegradable alternative to petroleum-based single-use plastics. The modifications significantly enhanced PLA crystallinity and mechanical performance, supporting its use in disposable packaging and tableware applications.

Polymers

Abstract The widespread use of traditional petroleum-based plastics is causing significant environmental pollution for example microplastics issues, due to its non-biodegradability. Poly (lactic acid) (PLA) as a representative biodegradable polymer is a promising candidate to replace petroleum-based plastics in some fields of disposable packaging materials and tableware. In this work, in order to improve the poor crystallization, mechanical and heat resistance performances of PLA, styrene-acrylonitrile-glycidyl methacrylate (SAG) as a chain extender and octamethylenedicarboxylic dibenzoylhydrazide (ST-NAB3) as a heterogeneous nucleating agent (HNA) were added simultaneously into PLA matrix. The chain-extended PLA (CPLA) with branch structures had smaller crystal sizes and higher crystal density, compared with those of pure PLA. In addition, thanks to the nucleation effect of ST-NAB3 and the development of “shish-kebab”, this tendency became more pronounced in CPLA/HNA systems. It was worth mentioning that, CPLA with the ST-NAB3 content of 1 wt.% (CPLA-1) possessed the highest crystallinity of 43.6%. Meanwhile, CPLA-1 had the best impact strength and heat deformation temperature of 38.9 kJ/m 2 and 91.3°C respectively, which had increased by 11.3 kJ/m 2 and 32.4°C contrast to pure PLA. On the whole, this study proposed a simple and effective method, which provided a new possibility for PLA modification research.

Share this paper