天然蛋白杂化硅溶胶阻燃棉织物的制备及燃烧性能分析

Preparation and combustion properties of natural protein hybrid silica sol flame retardant cotton fabric

采用溶胶-凝胶法,以正硅酸乙酯(TEOS)为前驱体、乙醇(C2H5OH)为溶剂、盐酸(HCl)为催化剂,1-γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)为偶联剂制备SiO2单一、复合和明胶(C102H151O39N31)杂化溶胶,利用激光粒度仪对溶胶粒径进行测定。采用浸渍-烘焙过程将溶胶后整理棉织物。利用热重分析(TG)、极限氧指数(LOI)、扫描电镜(SEM)、X射线光电子能谱(XPS)、傅里叶变换红外光谱分析(FTIR)对整理前后棉织物热解特性、阻燃性能、表面微观形貌、表面元素组成和官能团分布进行测试和表征,探讨明胶杂化溶胶阻燃效应和机理。结果发现:溶胶粒径分布表明纳米SiO2-KH570-明胶之间发生了化学键紧密结合,缩合生成Si-O-Si和氢键;SEM、FTIR和XPS分析表明具有明胶杂化组分的硅基溶胶在织物表面形成紧密涂层,呈现一定化学结合状态;TG分析表明,该结合状态对热稳定性影响显著,杂化溶胶后整理织物热解残炭率较原始棉织物提高872%,SiO2-KH570和SiO2-明胶复合溶胶体系间存在协效性;LOI分析表明,SiO2-KH570-明胶杂化溶胶阻燃效应最佳,LOI最高为25.2,对应ΔLOI/Δm最高为4.80 g^-1,SiO2单一溶胶和明胶及SiO2-KH570复合溶胶和明胶间体现明显协同效应;明胶可单方面提升SiO2单一溶胶及SiO2-KH570复合溶胶的凝胶化效应,促进三维微观骨架涂层结构形成,提升燃烧过程中棉织物脱水成炭作用。

By using sol-gel process,silica sols and gelatin hybrid silica sol were prepared by the hydrolysis and condensation reactions with TEOS as the precursor,EtOH as the co-solvent and HCl as the catalyst.Then,it was used to finish cotton fabric for higher flame retardancy.The particle size distributions of sols were characterized by laser particle size analyzer.The pyrolysis properties,flame retardancy,surface morphology and microscopic compositions of pure cotton fabrics before and after finishing were analyzed by using Thermogravimetry(TG),Limiting Oxygen Index(LOI),Scanning Electron Microscopy(SEM),X-ray Photoelectron Spectroscopy(XPS)and Fourier Transform Infrared Spectroscopy(FTIR).The flame retardant effect and mechanism of gelatin hybrid sol on pure cotton fabric were explored.The particle size distributions of the sols indicate that nano-SiO2 sol,KH570 and gelatin in the resulting hybrid sol are closely chemically bonded,and the condensation results in Si-O-Si and hydrogen bonds;SEM,FTIR and XPS analyses show that the silica-based sols with gelatin hybrid components form a close coating on the surface of the fabrics,showing a certain chemical bonding state;TG analyses show that the bonding state has a significant impact on thermal stability,and after being finished by the hybrid sol,the fabric shows an increased residual char ratio by 872%as compared to the original fabric.This indicates synergism between SiO2-KH570 and SiO2-gelatin composite sol systems.LOI analyses show that SiO2-KH570-gelatin hybrid sol has the best flame retardant effect with the highest LOI of 25.2 and the corresponding highestΔLOI/Δm of 4.80 g^-1,the single SiO2 Sol,SiO2-KH570 composite sol and gelatin showed obvious synergistic effects.Gelatin can enhance the gelation effect of SiO2 single sol and SiO2-KH570 composite sols solely in the process of burning,promote the formation of three-dimensional micro skeleton coating structure,and improve the dehydration and char formation of cotton fabrics during combustion finally.