Abstract

This study investigates unfractionated microalgae (Chlorella sp. HS2 (HS2)) as a new resource of biomass to develop microalgae-based bioplastic materials. For the fabrication of microalgae-based bioplastics, HS2 is melt-compounded with various polymers with different solubility. In addition, lipid-extracted HS2 (HS2-LE) is tested to compare the dispersion of unfractionated microalgae. Dispersion of HS2 in the polymer is assessed with morphological observations and image analysis, further evaluated based on mechanical, thermal, FT-IR spectroscopic, and rheological measurements. HS2 disperses in polymer with broad size distribution and forms large millimeter-sized agglomerates throughout the composite regardless of type of polymers. Meanwhile, size distribution of HS2 aggregates is shifting to smaller region at mixing condition realizing strong stress transfer. For poly(ethylene–vinyl acetate) (EVA)/HS2 showing smaller size distribution, the addition of 10% HS2 increases elongation at break of EVA. Moreover, lipid-extracted HS2 (HS2-LE) increases further ductility and strength of EVA composite due to better dispersion of HS2-LE. This preliminary study to screen out of several polymers to develop microalgae-based bioplastics has brought out a potential of HS2 for bioplastic application.

Graphical abstract

中文翻译：

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未分级微藻在各种聚合物中的分散及其对流变和机械性能的影响

摘要

这项研究调查了未分级的微藻（小球藻sp。HS2（HS2））作为生物质的新资源开发基于微藻的生物塑料材料。为了制造基于微藻的生物塑料，HS2 与各种具有不同溶解度的聚合物熔融复合。此外，还测试了脂质提取的 HS2 (HS2-LE) 以比较未分级微藻的分散情况。HS2 在聚合物中的分散通过形态观察和图像分析进行评估，并根据机械、热、FT-​​IR 光谱和流变测量进一步评估。HS2 分散在具有宽尺寸分布的聚合物中，并在整个复合材料中形成大的毫米大小的团聚体，而不管聚合物的类型如何。同时，在实现强应力传递的混合条件下，HS2 聚集体的尺寸分布正在向更小的区域移动。对于尺寸分布较小的聚（乙烯-醋酸乙烯酯）(EVA)/HS2，添加 10% HS2 会增加 EVA 的断裂伸长率。此外，由于 HS2-LE 的更好分散，脂质提取的 HS2 (HS2-LE) 进一步提高了 EVA 复合材料的延展性和强度。这项筛选出几种聚合物以开发基于微藻的生物塑料的初步研究揭示了 HS2 在生物塑料应用中的潜力。

图形概要