摘要
木质素结构中含有丰富的羟基与芳香官能团,具备大分子阻燃成炭剂的结构要求且成本低廉,绿色无污染。焦磷酸哌嗪(PPAP)是一种氮-磷协同的新型环保阻燃剂,具有优异的阻燃性能。将木质素与焦磷酸哌嗪按质量比1∶1复配得到一种木质素和焦磷酸哌嗪复合膨胀型阻燃剂,并将其用于阻燃改性环氧树脂(EP)。采用锥形量热分析(CONE)、极限氧指数测试(LOI)、垂直燃烧试验(UL-94)对所制备的“(木质素+焦磷酸哌嗪)复合膨胀型阻燃剂+环氧树脂”阻燃材料的燃烧行为与阻燃性能进行探究。采用热质量分析(TGA)、力学性能测试分析了阻燃材料的热稳定性与力学性能。采用傅里叶红外光谱(FTIR)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM),对环氧树脂复合材料燃烧后所得残炭层的化学结构、表面各元素的原子百分比、微观形貌进行分析表征。结果表明:木质素和焦磷酸哌嗪复合膨胀型阻燃剂(L+P)的引入提高了环氧树脂的阻燃性能与热稳定性。与纯环氧树脂相比,“质量分数20%的(木质素+焦磷酸哌嗪)复合膨胀型阻燃剂+环氧树脂”阻燃材料的极限氧指数由22.2%提高至27.5%,最大热释放速率、总烟释放量分别降低了60.11%、22.25%。扫描电子显微镜观测结果显示,复合膨胀型阻燃剂的添加明显促进了体系成炭,使得环氧树脂阻燃材料燃烧后残炭层更加致密。但粉体填料的加入不利于环氧树脂力学性能的提升,环氧树脂阻燃材料的弯曲强度与冲击强度均略有下降。
Lignin was compounded with PPAP in the mass ratio of 1∶1 as a new kind of intumescent flame retardant for epoxy resin(EP).Cone calorimetry(CONE),limiting oxygen index(LOI),and vertical combustion experiment(UL-94)were used to investigate the combustion behavior and flame retardancy of the epoxy resin flame retardant materials filled with lignin and pyrophosphoric acid piperazine compound intumescent flame retardant.Its thermal stability and mechanical properties were analyzed by thermogravimetric analysis(TGA)and mechanical property testing.Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),and scanning electron microscopy(SEM)were used to characterize the chemical structure,atomic percentage of surface elements,and microscopic morphology of the residual carbon layer after combustion.The results indicate that the introduction of the lignin and PPAP compound flame retardant(L+P)improved the flame retardant performance and thermal stability of epoxy resin.Compared with the neat EP,the limiting oxygen index(LOI)of“20%(lignin+pyrophosphoric acid piperazine)compound intumescent flame retardant+EP”increased from 22.2%to 27.5%,while its maximum heat release rate and total smoke emission decreased by 60.11%and 22.25%,respectively.From the SEM,the addition of compound intumescent flame retardant obviously promotes the formation of carbon,which makes the residual carbon layer of epoxy flame retardant material denser after burning.However,the powder flame retardant is not conducive to the improvement of mechanical properties of epoxy resin,and the bending strength and impact strength of epoxy resin flame retardant materials decrease slightly.
作者
尚欣宇
毕晓柯
谭海彦
张彦华
Shang Xinyu;Bi Xiaoke;Tan Haiyan;Zhang Yanhua(Northeast Forestry University,Harbin 150040,P.R.China)
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2023年第6期140-145,149,共7页
Journal of Northeast Forestry University
基金
国家自然科学基金面上项目(32071692)。
关键词
木质素
焦磷酸哌嗪
膨胀型阻燃剂
环氧树脂
阻燃性能
力学性能
Lignin
Pyrophosphoric acid piperazine
Intumescent flame retardant
Epoxy resin
Flame retardant performance
Mechanical property
