Abstract: This invention is directed to novel halogen-containing polythiols which impart improved flame retardancy to radiation cured thiol-ene compositions.

Abstract: The invention disclosed is directed to new curable liquid polyene-polythiol compounds containing particular polar groups, at least one unsaturated carbon-to-carbon bond disposed at a terminal position on a main or pendant chain of the molecule and at least one terminally disposed thiol group, with the sum of the unsaturated bonds and thiol groups per polyene-polythiol molecule being at least 3. Upon curing in the presence of a free radical generator such as actinic radiation, the polar polyene-polythiol compounds form solid elastomeric and rigid products which are useful in a variety of applications including coatings, adhesives, sealants and molded articles.