Preparation of Boron-coated Expandable Graphite and Its Application in Flame Retardant Rigid Polyurethane Foam

作     者：XU Dongmei LIU Xiu FENG Jie HAO Jianwei 

作者机构：National Laboratory of Flame Retardant Materials School of Materials Science and Engineering Beijing Institute of Technology Beijing 100081 P. R. China Beijing Institute of Aerospace Testing Technology Beijing 100074 P R. China 

出 版 物：《Chemical Research in Chinese Universities》 (高等学校化学研究（英文版）)

年 卷 期：2015年第31卷第2期

页      面：315-320页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：Supported by the National Natural Science Foundation of China(No.21474008) 

主　　题：Expandable graphite Polyvinyl alcohol Boric acid Rigid polyurethane foam Flame retardancy 

摘      要：A novel boron-coated expandable graphite（BEG） material was prepared by first wrapping polyvinyl alco- hoI（PVA） onto expandable graphite（EG） and then condensing with boric acid. The obtained BEG was characterized by scanning electron microscopy（SEM）, Fourier transform infrared（FT1R） spectroscopy, X-ray photoelectron spec- troscopy（XPS）, and tbermogravimetric analysis（TGA）. The fire performance and mechanical properties of the rigid polyurethane foam（RPUF） filled with BEG were investigated by limiting oxygen index（LOl）, horizontal and vertical burning, cone calorimetry（CONE）, and electronic tensile tests. BEG shows an improved compactness of the char layers upon thermal expansion, which is effective for the flame retardancy of RPUF. With a loading of 10%, RPUF/BEG exhibited a higher LOI, 〉10% reduction in heat release rate and carbon monoxide release, as well as a decrease in smoke release during the beginning of combustion compared to RPUF/EG. Moreover, the compressive strength and modulus of RPUF/BEG were increased. The improved flame retardancy of BEG on RPUF can be attributed to the suppression of the ＂popcorn effect＂ of EG by PVA-boric acid, and the improved mechanical property can be attributed to the presence of PVA.