Improvement in the physical properties of poly(lactic acid)/thermoplastic starch blends using oligo(lactic acid)-grafted starch

IF 2.3 4区化学 Q3 POLYMER SCIENCE

Polymer Journal Pub Date : 2024-06-18 DOI:10.1038/s41428-024-00918-5

Kazuki Shibasaki, Yu-I Hsu, Hiroshi Uyama

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引用次数: 0

Abstract

General-purpose petroleum-derived plastic remains in the environment for long periods and has significant impacts on oceans and land. Biodegradable and biomass plastics are being developed around the world as countermeasures. A poly(lactic acid) (PLA)/thermoplastic starch (TPS) blend is a promising ecofriendly alternative to biodegradable plastic made from plants. However, owing to the hydrophilicity of starch and the hydrophobicity of PLA, phase separation occurs between PLA and starch. Furthermore, PLA/TPS blends have poor water resistance because of the presence of starch, limiting their applications. In this study, to improve the affinity of PLA for starch, oligo(lactic acid)-grafted starch (OLAgSt) was synthesized as a compatibilizer for PLA/TPS blends, and the effect of its addition to PLA/TPS blends was evaluated. OLAgSt with different OLA molecular weights and degrees of substitution (DS) were synthesized, and their effects on PLA/TPS were compared. The results indicated that OLAgSt functioned as a good compatibilizer, improving the dispersibility of TPS in PLA with 4 wt% OLAgSt added to PLA/TPS and improving the water resistance. Moreover, the OLA molecular weight of OLAgSt was greater than that of DS. These results are expected to facilitate the development of PLA/TPS applications in the food packaging and biomedical fields. Blends of poly(lactic acid) (PLA) and thermoplastic starch (TPS) are promising biodegradable plastics, although their poor compatibility results in poor physical properties. In this study, oligo(lactic acid)-grafted starch (OLAgSt) was synthesized and added to PLA/TPS blends as a compatibilizer, and the physical properties of the obtained blends were evaluated. OLAgSt was synthesized by ring-opening polymerization of L-lactide using the hydroxy group of tapioca starch as an initiator. OLAgSt not only enhanced the dispersion of TPS within PLA, but also improved the biodegradability of the blend in a seawater environment.

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使用低聚（乳酸）接枝淀粉改善聚（乳酸）/热塑性淀粉混合物的物理性质

通用石油塑料长期存在于环境中，对海洋和陆地造成严重影响。作为对策，世界各地正在开发生物降解塑料和生物质塑料。聚乳酸（PLA）/热塑性淀粉（TPS）混合物是由植物制成的生物降解塑料的一种前景看好的生态友好替代品。然而，由于淀粉的亲水性和聚乳酸的疏水性，聚乳酸和淀粉之间会发生相分离。此外，由于淀粉的存在，聚乳酸/TPS 混合物的耐水性较差，限制了其应用。本研究为了提高聚乳酸与淀粉的亲和性，合成了低聚（乳酸）接枝淀粉（OLAgSt）作为聚乳酸/TPS 共混物的相容剂，并评估了将其添加到聚乳酸/TPS 共混物中的效果。合成了不同 OLA 分子量和取代度（DS）的 OLAgSt，并比较了它们对聚乳酸/TPS 的影响。结果表明，OLAgSt 具有良好的相容剂功能，在聚乳酸/TPS 中添加 4 wt% 的 OLAgSt 后，TPS 在聚乳酸中的分散性得到改善，耐水性也得到提高。此外，OLAgSt 的 OLA 分子量大于 DS。这些结果有望促进聚乳酸/TPS 在食品包装和生物医学领域的应用发展。

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来源期刊

Polymer Journal 化学-高分子科学

CiteScore

5.60

自引率

7.10%

发文量

131

审稿时长

2.5 months

期刊介绍： Polymer Journal promotes research from all aspects of polymer science from anywhere in the world and aims to provide an integrated platform for scientific communication that assists the advancement of polymer science and related fields. The journal publishes Original Articles, Notes, Short Communications and Reviews. Subject areas and topics of particular interest within the journal''s scope include, but are not limited to, those listed below: Polymer synthesis and reactions Polymer structures Physical properties of polymers Polymer surface and interfaces Functional polymers Supramolecular polymers Self-assembled materials Biopolymers and bio-related polymer materials Polymer engineering.