Preparation of nano-sized magnesium hydroxide as a flame retardant by high gravity technology and its application

The preparation of nano-sized magnesium hydroxide (NSMH) by high gravity method and surface modification of such made NSMH were investigated in this paper. Different kinds of surface modifiers were used in magnesium hydroxide filled in flexible PVC to improve the flame retardance and mechanical properties. The morphology and the dispersion of the particles were characterized by TEM, XRD, BET techniques. The experimental results showed that the mean size of NSMH was 70 nm and its BET area was 22.0641 m~2/g, which was larger than that of unmodified NSMH. According to the speed of sedimentation and oil absorption of NSMH, it could be inferred that modified NSMH had a better dispersion in organic media and it could improve the flame retardation of flexible PVC remarkably, and zinc stearate had a better modification effect compared with other modifiers. When 40 copies MNMH were added into flexible PVC, it exhibited much better in both flame retardance and mechanical properties.