Abstract：
With the escalating environmental and health concerns over petroleum-based plastics, sustainable and biodegradable cellulosic materials are a promising alternative to plastics, yet remain unsatisfied properties such as fragility, inflammability and water sensitivity for practical usage. Herein, we present a novel dual-network design strategy to address these limitations and fabricate a high-performance cellulosic composite bioplastic metafilm with the exceptional mechanical toughness (23.5 MJ m-3 ), flame retardance, and solvent resistance by in situ growth of cyclotriphosphazene-bridged organosilica network within bacterial cellulose matrix. The phosphorus, nitrogen-containing organosilica network, verified by the experimental and theoretical results, plays a triple action on significantly enhancing tensile strength, toughness, flame retardance and water resistance of composite bioplastic metafilm. Furthermore, cellulosic bioplastic composite metafilm demonstrates a higher maximum usage temperature (245 °C), lower thermal expansion coefficient (15.19 ppm °C-1 ), and better solvent resistance than traditional plastics, good biocompatibility and natural biodegradation. Moreover, the composite bioplastic metafilm have a good transparency of average 74 % and a high haze over 80 %, which can serve as an outstanding substrate substitute for commercial polyethylene terephthalate film to address the demand of flexible ITO films. This work paves a creative way to design and manufacture the competitive bioplastic composite to replace daily-used plastics.
摘要：
随着对石油基塑料的环境和健康问题的升级，可持续和可生物降解的纤维素材料是塑料的有希望的替代品，但仍然不满意的属性，如脆弱性，易燃性和水的敏感性实际使用。在这里，我们提出了一种新颖的双网络设计策略来解决这些限制，并制造出具有出色机械韧性（23.5MJ·m-3）的高性能纤维素复合材料生物塑料metafilm，阻燃性,通过在细菌纤维素基质中原位生长环三磷腈桥接的有机二氧化硅网络和耐溶剂性。磷，含氮有机硅网络，实验和理论结果验证,对显著提高抗拉强度起三重作用，韧性,复合生物塑料metafilm的阻燃性和耐水性。此外，纤维素生物塑料复合材料metafilm显示出更高的最高使用温度（245°C），较低的热膨胀系数（15.19ppm·°C-1），比传统塑料更好的耐溶剂性，良好的生物相容性和自然生物降解。此外，复合生物塑料metafilm具有平均74%的良好透明度和80%以上的高雾度，它可以作为商业聚对苯二甲酸乙二醇酯薄膜的出色基板替代品，以满足柔性ITO薄膜的需求。这项工作为设计和制造具有竞争力的生物塑料复合材料以替代日用塑料铺平了道路。
