Ultrahigh Thermoresistant Lightweight Bioplastics Developed from Fermentation Products of Cellulosic Feedstock
Ultrahigh Thermoresistant Lightweight Bioplastics Developed from Fermentation Products of Cellulosic Feedstock
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DOI：
10.1002/adsu.202000193
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发表时间：
2020-10-13
影响因子：
7.1
通讯作者：
Ohnishi, Yasuo
中科院分区：
文献类型：
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作者：
Nag, Aniruddha;Ali, Mohammad Asif;Ohnishi, Yasuo
利用可再生生物资源生产生物塑料是发展循环和可持续社会的先决条件。目前的生物塑料大多是热敏脂肪族聚合物，需要耐热的芳香族生物塑料。在本文中，使用代谢工程化的细菌从硫酸盐纸浆（一种不可食用的纤维素原料）生产3-氨基-4-羟基苯甲酸（AHBA）和4-氨基苯甲酸（阿坝）。将AHBA化学转化为3，4-二氨基苯甲酸（DABA）;随后，通过DABA的缩聚得到聚（2，5-苯并咪唑），并将其加工成耐湿热膜。DABA与少量阿坝的共聚显著提高了所得薄膜的降解温度（超过740摄氏度），从而产生有记录以来最耐热的塑料。密度泛函理论计算表明，阿坝的掺入增强了芳香族咪唑环之间的链间氢键。因此，提出了一种替代的有机分子设计的耐热塑料，而不使用重无机物，虽然连续的芳族杂环被广泛认为是理想的聚合物耐热性。这种创新的高分子设计增加了耐热性，可广泛应用于生产轻质材料的可加工塑料，预计将有助于发展更可持续的社会。
Production of bioplastics from renewable biological resources is a prerequisite for the development of a circular and sustainable society. Current bioplastics are mostly heat-sensitive aliphatic polymers, requiring thermoresistant aromatic bioplastics. Herein, 3-amino-4-hydroxybenzoic acid (AHBA) and 4-aminobenzoic acid (ABA) are produced from kraft pulp, an inedible cellulosic feedstock, using metabolically engineered bacteria. AHBA is chemically converted to 3,4-diaminobenzoic acid (DABA); subsequently, poly(2,5-benzimidazole) is obtained by the polycondensation of DABA and processed into an ultrahigh thermoresistant film. The copolymerization of DABA with a small amount of ABA dramatically increases the degradation temperatures of the resulting films (over 740 degrees C) to yield the most thermoresistant plastic on record. Density functional theory calculations indicate that the incorporation of ABA strengthens the interchain hydrogen bonds between aromatic imidazole rings. Thus, an alternative organic molecular design is proposed for thermoresistant plastics without using heavy inorganics, although continuous aromatic heterocycles are widely considered ideal for polymer thermoresistance. This innovative macromolecular design increases thermoresistance and can be widely applied to well-processable plastics for the production of lightweight materials and is expected to contribute to the development of a more sustainable society.