阻燃抗熔滴聚酯的设计合成与结构性能研究

Polyester(PET) fiber has accounted for about ninety percent of all synthetic fibers, which has widely been used in various fields, and China has been the first largest country for production of polyester in the world. However, since the polyester exhibits the inherent flammability and ease of melt-dripping, the flame retardation of such material is extremely necessary to meet broader applications. Unfortunately, the existing commercial flame retardants for polyesters would cause the polyesters to melt-drip seriously during fire, thus leading to secondary damage and an immediate empyrosis during fire. Therefore, how to address the contradiction between the flammability and dripping behavior for polyester through intrinsic flame retardation becomes a real challenge for both scientific and industrial fields. .In order to solve the contradiction between the non-flammability and non-dripping for the flame-retardant PET, we will design and synthesize a series of the third monomers for polyesters and the corresponding copolyesters with thermo-crosslinkable groups, which can produce chemical cross-linkings at a certain temperature, and the cross-linked structures have the potential char-forming tendency. As a result, the flame retardancy and anti-dripping performance of the copolyesters could be achieved simultaneously only by introducing the crosslinkable groups-containing co-monomers through copolymerization. Positive contribution of the cross-linking reactions of these groups to the flame retardancy and anti-dripping performance will be systematically investigated, and the potential mechanism will be revealed. Based on the above-mentioned investigations, the relationship among “the molecular structure of the copolyester”, “flame retardancy and anti-dripping performance”, “rheological behavior and processability” and “physical and mechanical properties” will be established, and hence to explore an effective solution to resolve the contradiction between the non-flammability and non-dripping for the flame-retardant polyesters. .Therefore, this project has both scientific meanings and application prospects, which will provide a scientific basis for developing the environment-friendly flame-retardant polyesters with high flame retardance and anti-dripping performance, as well as excellent comprehensive physical and mechanical properties. This project will propose a new thought to develop a new kind of flame-retardant polymer materials.

全球聚酯年产量约9千万吨，我国占53%，成为第一大聚酯生产国，其高附加价值的阻燃产品具有重大需求。但是，因聚酯固有的易燃和熔滴特性，使现有的对聚酯能有效阻燃的无卤阻燃剂难以同时解决其阻燃与抗熔滴性，这是阻燃领域长期未得到解决的技术难题，从而限制了聚酯在一些重要领域的应用。针对这一技术难题，本项目从聚酯大分子的分子设计入手，设计合成一系列分别在大分子的主链或侧基引入具有不同结构可在特定温度(如燃烧)条件下形成“化学交联”基团的聚酯，通过对所合成的具有不同结构的聚酯在不同温度下的结构变化(交联行为)及其对流变与加工性及熔滴行为影响的研究、高温或燃烧条件下的炭化行为与凝聚相阻燃机理的研究，建立聚酯分子结构与成形加工性、阻燃性和抗熔滴性以及力学性能等的构效关系，探索出有效解决聚酯的“阻燃”与“抗熔滴”相矛盾这一难题的途径，为制备综合性能好的同时具有高阻燃性和不熔滴的聚酯奠定科学基础

聚对苯二甲酸乙二酯（聚酯、PET）作为我国单一品种产量最大的合成高分子材料（年产量>5千万吨），其固有的易燃性和高温熔滴特性是领域亟待突破的难题。目前商业化的含磷阻燃聚酯是通过促进“熔体滴落带走热量”达到阻燃效果，因此会导致更加严重的熔滴行为。项目针对传统阻燃技术无法解决的“聚酯阻燃与抗熔滴相矛盾”的国际性难题，从聚酯的分子链结构和燃烧特性出发，提出聚酯在高温下的高熔体黏度和强成炭能力是实现阻燃抗熔滴的关键，进而构建了一系列可高温炭化的阻燃抗熔滴聚酯体系，并同时实现了阻燃抗熔滴聚酯的多功能与高性能。项目设计合成了一系列无卤无磷的阻燃第三单体及相应的共聚酯，通过阻燃结构单元高温下的“可控化学自交联”、“物理相互作用”、“高温重排”、“三源一体”等作用机制，一方面显著提高了聚酯燃烧时的熔体黏度和强度，进而有效抑制熔滴的产生，实现了燃烧时的不熔滴；另一方面这些阻燃结构单元会参与聚酯的固相燃烧成炭，形成的稳定致密炭层在阻隔热量传递和氧气交换的同时，抑制了聚酯基材进一步分解，从而提高了阻燃性能。此外，通过阻燃第三单体的分子结构设计，制备的阻燃抗熔滴聚酯可兼具高强度、高玻璃化温度、高热稳定等高性能，以及阳离子可染、形状记忆、抗紫外等多功能。项目形成了从阻燃单体的设计合成、到阻燃抗熔滴聚酯制备和应用的完整自主知识产权保护体系，为相关聚酯体系的中试放大合成和相关技术开发与应用转化奠定了科学基础。本项目开辟了通过促进聚酯自身高温炭化实现阻燃抗熔滴的全新途径，突破了市面上含磷阻燃聚酯“促熔滴”的技术瓶颈，实现了阻燃抗熔滴聚酯的功能化与差别化，形成的原理和方法也指导了阻燃抗熔滴的PTT、PBT和PA6等材料的成功合成。本项目相关研究已发表和接受发表SCI论文31篇（第一标注27篇），其中有1篇国际权威期刊和1篇科学通报特邀综述论文，申请发明专利17项，其中PCT国际专利1项和台湾发明专利1项，已授权12项，举办国际学术会议2次，双边国际学术研讨会4次，国际学术会议大会特邀请报告6次，培养硕士和博士研究生20人次。本项目取得的成果作为部分获奖内容，获得国家自然科学二等奖1项，入选中国科协设立的首批“科创中国”先导技术榜单(材料领域共10项)。