Solid state shear milling to prepare magnesium hydroxide flame-retardant polyamide 6 with high performance

A novel processing method, that is, solid state shear milling (S3M), was adopted to compound high loading inorganic flame-retardant magnesium hydroxide with polyamide 6 by using our self-designed pan-mill equipment. S3M can effectively pulverize PA6. increase the interfacial interaction of the resin and magnesium hydroxide, and achieve their even blending, thus effectively controlling the state of the dispersion phase in solid state. With the co-milled composite powder as flame retardant master batch filled in original PA6 pellets, it can greatly improve the compatibility of the system, modify the distribution process of magnesium hydroxide, and decrease the dispersion phase size in the following melt processing. As a result, S3M technology can remarkably increase the melt flowability of the composite materials, and obtain obviously enhanced flame retardance and mechanical performance, thus providing an effective solution to the poor processibility and deteriorated performance of magnesium hydroxide flame-retardant PA6 obtained through direct melt processing.