Effect of phosphorus-containing modified magnesium hydroxide on the mechanical properties and flammability of PLA/MH composites

In this study. a novel modifier (PPD-PTES) for Magnesium Hydroxide (MH) was successfully synthesized from (3-Aminopropyl) triethoxysilane and phenylphosphonic dichloride aiming to improve not only the compatibility of MH with polymer but also its efficiency. Fourier transform infrared spectroscopy (FTIR), H-1,P-31-nuclear magnetic resonance (NMR) were carried out to characterize its structure. The flammability, thermal degradation and mechanical properties of the PLA/MH composites were investigated by limiting oxygen index (LOI), microscale combustion calorimetry (MCC), thermogravimetric analysis (TGA) and tensile test. The results showed that the introduction of MH can significantly reduce the peak of heat release rate (PHRR) and total heat release (TIM). Additionally, the LOI of modified MH reinforced PLA has also increased compared to the unmodified MH reinforced PLA. Further, results of tensile test proofed that the organic modification could improve the compatibility of MH with the polymer, but only slightly decrease brittleness.