The invention belongs to the technical field of
flame-retardant materials, and relates to a sulfathiazolyl P / N / S-containing
halogen-free
flame retardant as well as a preparation method and application thereof. The
halogen-free
flame retardant containing
phosphorus,
nitrogen and
sulfur elements is obtained by taking diphenyl hypophosphorous
chloride as a basis, preparing a flame-retardant intermediate through
nucleophilic substitution reaction between diphenyl hypophosphorous
chloride and an
aldehyde group-containing phenolic compound, then forming a
Schiff base structure by the intermediate and
sulfathiazole, and finally performing
addition reaction with DOPO (9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-
oxide). The flame retardant can play a synergistic flame-retardant role of
phosphorus-
nitrogen-
sulfur elements, and has a good flame-retardant effect. When the flame retardant disclosed by the invention is used for modifying
epoxy resin, the UL-94V-0 level can be reached when the addition amount is less than 5% of the total
mass. The influence on Tg of an
epoxy resin cured product is small, and the
smoke suppression and
char formation performance and the
mechanical property of the
epoxy resin cured product can be remarkably improved. The prepared flame-retardant epoxy resin has good
smoke suppression property and
char forming property, has good compatibility with epoxy resin, and improves the stability of cured epoxy resin in
processing.