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采用乙烯基硅烷在纳米氢氧化镁(MH)表面引入乙烯基后与苯乙烯进行原位聚合,制备了苯乙烯原位聚合改性氢氧化镁(MMH)。将改性前后的MH分别与聚丙烯(PP)熔融复合制备了不同的MH/PP复合材料,采用扫描电镜和毛细管流变仪研究了复合材料的形态结构和流变特性。结果表明:MH/PP复合材料为剪切变稀的非牛顿流体,其表观黏度、非牛顿指数大于PP。随着填充量的增加,MH/PP复合材料表观黏度增大,非牛顿指数总体上也表现出增大的趋势。低的填充量降低了PP的黏流活化能,随着MH填充量的增加,复合材料的黏流活化能明显增大。然而,MH的苯乙烯原位聚合改性显著改善了复合材料的分散性,改性后MH的“滚珠”效应明显降低了复合材料的表观黏度,非牛顿指数和黏流活化能也比PP熔体的小,且黏流活化能随改性MH填充量的增加而进一步减小。
In situ polymerization of styrene with modified vinyl magnesium hydroxide (MMH) was prepared by in situ polymerization of styrene with vinyl silane on the surface of nano-magnesium hydroxide (MH). Different MH / PP composites were prepared by melt-mixing polypropylene (PP) with MH before and after modification. Morphology and rheological properties of the composites were investigated by scanning electron microscopy and capillary rheometer. The results show that the MH / PP composites are shear-thinned non-Newtonian fluids with apparent viscosity and non-Newtonian index greater than PP. The apparent viscosity of MH / PP composites increases with the increase of the loading, and the non-Newtonian index also shows an increasing trend overall. Low loadings reduced the viscous flow activation energy of PP. With the increase of MH loading, the viscous flow activation energy of composite increased obviously. However, the in-situ polymerization modification of styrene by MH significantly improved the dispersibility of the composites. The modified MH “ball” effect significantly reduced the apparent viscosity of the composites. The non-Newtonian index and the viscous flow activation energy It is smaller than PP melt, and the activation energy of viscous flow can be further reduced with the increase of modified MH loading.