基于氰基结构高温自交联阻燃耐熔滴共聚酯的设计、合成及性能研究

Poly(ethylene terephthalate)(PET) have been widely used because of their excellent mechanical, thermal stability, outstanding chemical and moisture resistance. Unfortunately, the usefulness of PET for many applications is often limited due to their inherent flammable and heavy melt-dripping. Many studies have been conducted to remedy these shortcomings, but how to resolve the conflict between the flammability and melt-dripping is still a challenge for development of flame-retardant PET in real applications. Face this dilemma, we designed and synthesized a series of flame-retardant-free co-polyesters with high temperature self-crosslinkable cyano groups which were not active at the temperature of synthesis and processing but could cross-link rapidly in an appropriate temperature range, and the flame retardation and anti-dripping of polyesters simultaneously achieved, despite the absence of phosphorous or halogen flame-retardant elements. The chemical structures, thermal stability, cross-lingking behaviors, flame retardancy, mechanical properties, of as-synthesized copolyesters with various cyano groups were well studied. The flame retardant and anti-dripping mode of action from self-cross-linking was investigated in detail. We will systematically investigate the structure-property relationship of the co-polyesters systems with cyano groups. This project may be carried out to obtain properties controlled high temperature self-crosslinked co-polyesters systems, and provide valuable new and green strategies for the preparation and application of flame retardant PET.

聚酯因性能优异而应用广泛，但易燃且产生熔滴的缺陷严重限制了其进一步应用。目前针对聚酯的阻燃研究已有大量的文献报道，但仍面临“阻燃与耐熔滴相矛盾”的难题。本项目基于聚合和加工温度下保持惰性，更高温度(聚酯熔点和分解温度之间的温度区间)发生化学交联反应而使熔体粘度骤增并加速形成致密炭层进而达到阻燃目的的方法，将不同氰基基团结构的共聚单体引入到聚酯分子链中制备不含传统阻燃元素的高温自交联阻燃共聚酯，同时赋予聚酯阻燃和耐熔滴性能。改变共聚酯分子中氰基基团结构，实现阻燃共聚酯高温自交联性能的可控，提高材料结晶、力学等性能，赋予阻燃共聚酯优异的综合性能。揭示共聚酯分子结构与性能的关系，探讨其自交联机制及阻燃耐熔滴机理，实现阻燃聚酯可纺。. 本项目提出合成的高温自交联阻燃共聚酯仅通过高温度下发生的交联成炭作用实现阻燃及抗熔滴的目的，交联性能可控，且无卤无磷，可实现真正意义上的环保阻燃

聚酯因性能优异而应用广泛，但易燃且产生熔滴的缺陷严重限制了其进一步应用，本项目通过分子结构设计将不同氰基结构的基团引入到聚酯分子链中制备不含传统阻燃元素的高温自交联阻燃共聚酯。通过分析共聚酯高温的流变行为、裂解产物及高温裂解过程、残炭的结构及微观形貌，具体研究了引入的基团结构对共聚酯阻燃抗熔滴性能的影响，揭示了揭示共聚酯分子结构与性能的关系，同时探讨了其自交联机制及阻燃耐熔滴机理：在燃烧过程在，分子链中的氰基基团可三聚形成三嗪环或酞菁环，促使分子链交联，增加聚酯的熔体黏度，从而抑制熔滴的形成；分子链中的芳醚结构与小分子自由基反应形成稳定的含氧芳香杂环，促进共聚酯成炭，基于芳醚与芳腈结构的协同作用，同时赋予聚酯阻燃和耐熔滴性能。.本项目合成的高温自交联阻燃共聚酯仅通过高温度下发生的交联成炭作用实现阻燃及抗熔滴的目的，且无卤无磷，为聚酯工业真正意义上的环保阻燃应用提供了一定的参考价值。