改性硅分子筛在PLA中的扩链和阻燃性能研究

Study on Chain Extension and Flame Retardancy of Poly(lactic acid)with Modified Silica Molecular Sieves

采用硅烷偶联剂对介孔硅分子筛SBA-15进行表面改性,键合了能与聚乳酸(PLA)发生化学反应的氨基(—NH2)基团;采用傅里叶红外光谱仪、X-射线多晶衍射仪、扫描电子显微镜等对改性分子筛的结构进行了表征。结果表明,—NH2成功地接枝在了介孔硅分子筛SBA-15上,且分子筛的多维孔道结构保持了完整;氨基改性分子筛(NH2-SBA-15)可作为扩链剂与PLA进行分子键合,当添加0.5%(质量分数,下同)的NH2-SBA-15时,PLA体系的复合黏度和储能模量得到了显著提高,且此扩链PLA的冷结晶温度明显降低,燃烧过程中热释放速率及一氧化碳释放速率均下降,体现出良好的结晶能力和自阻燃性能。

In this paper, mesoporous silica molecular sieve, SBA-15, was surface modified byreacting with a silicon coupling agent, and then its structure was characterized by Fourier-transform infrared spectroscopy, X-ray powder diffraction and scanning electron microscopy. The results indicated that the framework structure of molecular sieve was well maintained and the amino groups were grafted on the molecular sieve through covalent bonding. When 0. 5 wt % ofmodified silica molecular sieve was added into poly（lactic acid） （P LA ） ,the complex viscosity and storage modulus of PLA increased significantly. This ^ugge^ts that the molecular sieve performed an effective chain extension for PLA Moreover, the chain-extended PLA exhibits a decrease in cold crystallization temperature,mdieating a better crystallization capability. Furthermore,its release rates of carbon oxygen and heat were also reduced as a resutt of the enhancement of flame retardancy.