Colourless coarse-grained penta:bromo-benzyl acrylate! polymer prepn. - by using penta:bromo-toluene-contaminated penta:bromo-benzyl halide in penta:bromo-benzyl acrylate prepn.

摘要

Polymeric pentabromobenzyl acrylates are prepd. by reacting pentabromotoluene with Cl2 or Br2, esterifying the pentabromobenzyl halide formed with alkali acrylate and polymerising the acrylate ester. Novelty consists in (i) using a pentabromotoluene-contaminated pentabromobenzyl halide for pentabromobenzyl acrylate prepn. and (ii) sepg. the insoluble parts obtd. during esterification before polymerisation, while maintaining esterification temp., pref. 80-120 degrees C. Pentabromobenzyl acrylate (co)polymers are used as flame-retardant for thermoplastics. Pentabromotoluene is easily sepd. Pentabromobenzyl acrylate can be recovered as a pure white prod. The hot pentabromobenzyl acrylate-contg. filtrate soln. can also be used directly for polymerisation, to yield an easily filtered, coarse-grained colourless polymer. 141.4 pts. wt pentabromobenzyl bromide, contaminated with 8 wt.%.