Effects of the content of silane coupling agent KH‐560 on the properties of LLDPE/magnesium hydroxide composites

Based on traditional idea of molecular coupling effect, surface modifiers were helpful to improve the performances of inorganic/organic composites. However, it was also widely accepted that the content of surface modifier should be controlled in a suitable range, and more or less modifiers could not reach to optimal properties. The intrinsic reason for this phenomenon was not clear until now. In this article, the influences of the content of surface modifier: silane coupling agent KH-560, on the final performances of linear low-density polyethylene (LLDPE)/magnesium hydroxide (MH) composites, have been studied. The performance tests of LLDPE/MH composites, including mechanical properties measurements, thermal oxidative stability analysis, and surface morphology observation, all confirmed that there was an optimal content range of surface modifier. However, further morphology investigation of the modified MH by particle size and particle size distribution analyzer showed that, the particle size and particle size distribution of MH both increased as the content of KH-560 increased. ATR-FTIR analysis proved that silane grafting was achieved on the MH particle surface, which not only improved the compatibility between MH and LLDPE for molecular coupling effect, but also caused bigger particle size and wider particle size distribution, which were disadvantageous to improve the performances of the composites. The two opposite effects of the surface modifiers mentioned above affected the final performances of the composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010