Abstract: In this paper, mesoporous silica molecular sieve, SBA-15, was surface modified by reacting 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 % of modified silica molecular sieve was added into poly(lactic acid) (PLA), the complex viscosity and storage modulus of PLA increased significantly. This suggests that the molecular sieve performed an effective chain extension for PLA. Moreover, the chain-extended PLA exhibits a decrease in cold crystallization temperature, indicating a better crystallization capability. Furthermore, its release rates of carbon oxygen and heat were also reduced as a result of the enhancement of flame retardancy.

Key words: poly(lactic acid), Reactive Flame Retardant, mescporous silica molecular sieve, chain extension, modification