Aluminated mesoporous silica as novel high-effective flame retardant in polylactide

In this article, mesoporous flame retardant (Al-SBA-15) was prepared by post-grafting of aluminum isopropoxide on the surface of mesoporous silica (SBA-15). X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectrum (FT-IR) and N2 adsorption–desorption measurement were utilized to investigate the structure of mesoporous materials. Al-SBA-15, SBA-15 and fumed silica were added into polylactide, respectively, to carry on comparative study. Results showed limiting oxygen index (LOI) of polylactide composite was significantly increased by Al-SBA-15, accompanied with UL-94V-0 rating. Moreover, the incorporation of 0.5 wt% of Al-SBA-15 reduced the peak of heat release rate of PLA composite by 15.1% compared with pure PLA and decreased the produced smoke amount. Al-SBA-15 reduced the volatile products of PLA during thermal degradation process that was detected by mass spectroscopy (MS). Al-SBA-15 also improved the hydrolysis resistance and tensile properties of PLA composite. Results showed that Al-SBA-15 was a high-effective additive to improve the fire-resistance, smoke inhibition, hydrolysis resistance and mechanical properties of PLA.