In this paper, a silane coupling agent A-174(3-methacryloxypropyl trimethoxysilane) was used as a surface modifier to modify Magnesium hydroxide by dry process. The modification effect was evaluated by activation index and oil absorption, and the Magnesium hydroxide before and after modification were characterized by infrared spectroscopy, thermogravimetry and Scanning electron microscope analysis, the mechanism of silane coupling agent A-174 modified Magnesium hydroxide was investigated.
The optimum process conditions of A-174 modified Magnesium hydroxide were determined as follows: 1.0 wt. % A-174, modified temperature 140 ° C, modified time 10 min, modified stirring speed 3000 rpm. It was proved that silane coupling agent A-174 was chemically adsorbed on the surface of Magnesium hydroxide powder, and the Magnesium hydroxide powder modified by A-174 had good dispersibility and hydrophobicity. MHEVA composite was prepared by melting and mixing silane coupling agent A-174 modified Magnesium hydroxide powder and Eva resin with a specific formulation (modified mheva = 1.21) using a torque rheometer, the mechanical properties were studied.
The results showed that the mechanical properties of EVA composites modified with silane coupling Magnesium hydroxide were significantly better than those of EVA composites without modified Magnesium hydroxide. The maximum elongation at break and tensile strength of the modified MH/Eva Composites were 138.48% and 8.78 MPA respectively, which were higher than those of the unmodified MH/Eva Composites (72.85% and 6.18 MPA respectively) , by 90.09% and 42.07% respectively. At the same time, the optimum modification conditions of the composites which can adapt to different mechanical properties are obtained.
