桐油在阻燃型聚氨酯硬泡中的应用基础研究

Tung oil is obtained from the seeds of tung trees, and it is an important and abundantly available natural chemical in China. Tung oil is used for traditional wood finishing, oil paints and printing inks. Because of its characteristic conjugated carbon-carbon double bonds which can be easily derivatized, tung oil has received extensive investigation for other higher value products. Early, our group first introduced the tung oil-based flame retardant rigid polyurethane foam (RPUF). RPUFs have been widely used as insulation materials in many fields due to their excellent physical properties. However, it is vulnerable to fire risk and can emit a large amount of smoke at burning. Therefore, flame retardancy is an important requirement for RPUF to be used in buildings. Research of flame retardant RPUFs is a newly emerging area and there are a many challenges to be addressed. The purpose of this project is to develop an inherent high flame retardant RPUF product from the tung oil feedstock. Our approach is to introduce the halogen-free flame retardant nitrogenous, phosphorus heterocyclics and silicon groups into tung oil-based polyols for RPUFs. The objectives of this project include: 1) explore the effect of the introduction manner and content of flame retardant groups on the properties of the polyols; 2) investigate the compatibility with the blowing agent, polymerization curing behavior, reactivity difference of tung oil-based flame retardant polyols in the preparation of RPUFs; 3) study the thermal stability and combustion property of the resulting tung oil-based RPUF; 4) analyze the chemical structure and composition of the combustion product; 5) investigate the synergetic effects of nitrogenous, phosphorus heterocyclics and silicon elements on the flame retardancy, and; 6) figure out the effect of content of tung oil acid on the mechanical properties of the RPUFs, the structure-activity relationship between tung oil-based polyols and flame retardant properties of RPUF, meanwhile explore the flame retardant, smoke suppression mechanism and instruct the structure design of inhere flame retardant polyols. Successful completion of this project will layout the framework for future commercialization of the tung oil-based flame retardant RPUFs and contribute the knowledge base of synergetic flame retardant polymers.

我国林业特色资源桐油的应用基本上停留在初产品阶段，高附加值利用率低，扩大桐油的应用领域迫在眉睫。本项目首次开展桐油在阻燃型聚氨酯硬泡中的应用基础研究；针对生物基聚氨酯硬泡保温材料易燃烧、燃烧发烟量大等缺点，以桐油为原料，设计合成含氮、磷、硅等非卤素阻燃基团的结构型阻燃多元醇和聚氨酯硬泡；考察在桐油分子结构中引入阻燃元素的方式和比例对多元醇性能的影响；研究结构型桐油基阻燃多元醇在聚氨酯硬泡制备过程中的聚合反应行为、活性差异及与发泡剂的混溶性能；探讨桐油酸含量对聚氨酯硬泡力学性能的影响行为以及不同阻燃元素在聚氨酯硬泡热释放、烟释放及成炭方面的协效关系，揭示阻燃、抑烟机理，进一步指导阻燃多元醇的结构设计。本项目可为桐油在聚氨酯硬泡中的高附加值利用和高分子材料的协效阻燃研究提供理论基础。

我国林业特色资源桐油的应用基本上停留在初产品阶段，高附加值利用率低；研究开发油桐深度加工新产品，拓宽桐油的应用领域，增加桐油附加值，是油桐产业发展的主要趋势。本项目针对生物基聚氨酯硬泡保温材料易燃烧、燃烧发烟量大等缺点，以桐油为原料，利用桐油特殊的化学结构与活泼的化学性质，替代石化原料，设计合成出一系列新颖结构含阻燃元素如磷、硅、氮的阻燃型桐油基多元醇，替代部分或全部的石油基多元醇制备出聚氨酯泡沫材料。系统地考察了影响桐油结构改性的各种影响因素，解决了阻燃型桐油基多元醇在硬泡制备过程中的反应行为及与其他助剂混溶性的问题。桐油基阻燃聚氨酯硬泡其热稳定性和机械性能可与石油基聚氨酯硬泡相媲美，添加了阻燃型桐油基多元醇的聚氨酯硬泡的热稳定性得到提高，不同的聚氨酯硬泡的初始分解温度都高于250℃；机械性能较好，压缩强度最高可达0.87MPa；阻燃性能优异，其极限氧指数最高可达26.2%。同时合成了系列添加型无机阻燃剂和反应型无机阻燃剂，进而和阻燃型桐油基多元醇复配制备出一系列兼具优良的阻燃性和良好的机械性能的聚氨酯硬泡，阐明了阻燃型桐油基多元醇的添加量对聚氨酯硬泡的机械性能、热力学性能、表观形貌和燃烧行为的影响规律，明确了无卤阻燃剂、桐油基阻燃型多元醇对聚氨酯硬泡的机械性能和阻燃性能的协同作用机制及抑烟机理。相关成果发表论文12篇，其中SCI收录论文6篇，EI收录论文1篇，中文核心论文5篇；转让技术1项，获得2019年梁希林业科技进步二等奖1项；培养博士研究生2名、硕士研究生1名。