Magnesium hydroxide has all the characteristics required for use as a
flame retardant filler. It can be made synthetically with high purity
and in a range of useful morphologies, responds well to surface modifi
ers and decomposes endothermically with release of water at temperatur
es close to those of polymer degradation and high enough to allow inco
rporation into most polymer types. Crystal growth is difficult and, un
til recently, particles with suitable morphologies were too expensive
for other than niche applications. New production methods are now avai
lable that offer the prospect of improved morphology control and bette
r cost effectiveness. Use of this filler enables high levels of flame
retardancy to be achieved in a wide range of polymer types, including
ethylene vinyl acetate, polypropylene and polyamides. (C) 1996 Elsevie
r Science Limited