国家自然科学基金 (31872611，31972844)；工信部高技术船舶科研项目 (工信部装函360号)
Funding projects: Project supported by the National Natural Science Foundation of China (31872611); Ministry of industry and information technology high tech ship research project (Engineering development of semi submersible agriculture equipment); Science and Technology Innovation and R&D Project of China Shipbuilding Industry Corporation (201817K); Taishan Talents Leadership Talent project (2018RPNT-TSYC-001) and China Agriculture Research System (CARS-50)
不可降解渔具造成的“白色污染”和“幽灵捕捞”问题已严重威胁到海洋的生态环境，开发可降解渔具材料已经成为我国渔业可持续发展的有效途径之一。本实验采用熔融纺丝法制备淀粉 (STR)/高密度聚乙烯 (HDPE)/纳米蒙脱土 (MMT)纳米复合纤维，研究MMT对纳米复合纤维的热学性能、力学性能、动态力学性能与海水降解性能的影响。结果显示，引入MMT后，纳米复合纤维的熔融温度 (Tm)移向低温，结晶度增加，而断裂强度下降。此外，MMT的加入显著降低了聚乙烯的玻璃态储能模量和内部损耗，但对淀粉相影响不显著。4个月海水降解结果显示，与STR/HDPE纤维相比，STR/HDPE/MMT纳米复合纤维失重率增加了约5 %，纤维直径减小了约11 %，这表明MMT加快了STR/HDPE纤维的降解过程。本实验系统研究了MMT改性淀粉基纳米复合纤维的海水降解性能，可为渔业等海洋产业用降解新材料的开发与应用提供参考。
With the development of fishery economy, fishing gear materials, such as cotton, which are generally biodegradable, have been replaced by synthetic materials, such as polyethylene, polypropylene, and polyamide, which are difficult to be degraded. Moreover, fishing nets made from synthetic fibers, are not able to degrade in marine environment for decades. When they are lost or abandoned at sea, they will continue to trap fish and other animals, becoming "ghost fishing" gears. In face of the threats of "white pollution" and "ghost fishing" resulting from the use of non-degradable fishing equipment, the development of biodegradable fishing materials has become one of an effective path towards the sustainable development of the fisheries. Starch is widely present in nature, renewable, and can be used as a biodegradable material. However, due to poor processing and mechanical properties, they are often blended with other polymer materials. It is noted that the purpose of accelerating or slowing down the degradation of composite materials can be achieved by adding nanomaterials to modify biodegradable materials. Based on this, the starch (STR)/high-density polyethylene (HDPE)/montmorillonite (MMT) nanocomposite fibers were prepared by melt-spinning method, and the effect of nano-MMT on the thermal properties, mechanical properties, dynamic mechanical properties and degradation behavior under seawater of nanocomposite fibers was studied. The results showed that the melting temperature (Tm) of the nanocomposite fibers was reduced, the crystallinity of the nanocomposite fibers increased, and their breaking strength decreased as well. What’s more, the addition of MMT significantly reduced the glassy storage modulus and internal loss of polyethylene, but it had little effect on the starch. After 4 months of seawater degradation, compared with that of STR/HDPE fibers, the weight loss rates of STR/HDPE/MMT nanocomposite fibers increased by about 5%, and the loss of fiber diameter increased by about 11%. This indicated that MMT accelerated the degradation process of STR/HDPE fibers. This paper systematically studies the seawater degradation properties of the MMT modified starch-based nanocomposite fibers, which can provide reference for the development and application of biodegradable materials for marine industries such as fisheries.