Flame retardant fillers have been known and
used industrially for many years. The scientific
principles underlying their use has recently been
described in detail by Rothon.’ They mainly
produce their effect by decomposing endothermically,
with the release of an inert gas, at
temperatures close to those at which polymers
degrade. This temperature must be high enough
to enable the filler to be incorporated into the
polymer.
High loadings are needed to produce a useful
effect and so their filler properties are of great
importance if useful composite properties are to
be maintained. This paper examines the suitability
of one particular material, magnesium
hydroxide, for use as a flame retardant filler