氢氧化镁表面有机化及在阻燃PVC中的应用

Surface Organification of Magnesium Hydroxide and the Application in Flame-retardant PVC

采用原位聚合的方法在氢氧化镁[Mg（OH）2]表面接枝聚合聚甲基丙烯酸甲酯（PMMA）。考察了PMMA包覆量对Mg（OH）2粉体的吸油值、水中的沉降速度、水接触角以及对阻燃PVC复合材料中的氧指数（LOI）、形貌结构及力学性能的影响。结果表明，随着PMMA包覆量的增加，粉体的吸油值及粉体在水中的沉降速度明显减小，水接触角明显变大。在PVC复合材料中的氧指数减小，但变化不大。形貌结构分析表明，PMMA经处理后粉体与PVC基体的相容性明显提高，力学性能由于粉体的加入量随着PMMA包覆量的增加而增多，导致拉伸强度和撕裂强度逐渐降低，断裂伸长率先增大后减小。

Poly methyl methacrylate （PMMA） was grafted on the surface of Magnesium hydroxide by in- situ polymerization methods and the relationship between the coating amount of PMMA and the Mg （OH）2 powders oil absorption value, the settling veloeity in water, the water contact angle as well as the oxygen in- dex （LOI） in flame-retardant PVC composite materials, morphology and mechanical properties of the struc- ture were investigated. The results showed that with the increasing amount of PMMA-eoated, the oil absorp- tion value and the settling velocity in water were significantly reduced and the water contact angle hecame lar- ger. LOI of PVC composite materials was decreased hut changed little. The morphology and structural analy- sis indicated that the compatibility between the Mg（OH） 2 powder which was eoated by PMMA and PVC ma- trix was improved significantly. In mechanical properties, with the amount of PMMA-eoated increasing, the dosage of the powder increased, the tensile strength and tear strength decreased gradually, the breaking elon- gallon has a turn, increased firstly and then decreased.