▁Col onial ▁Social ▁Science ▁Research ▁Council ▁( 1 9 4 4 ) ▁ ▁References ▁ ▁Category : Res earch ▁coun c ils <0x0A> </s> ▁A ▁therm os et ting ▁polym er , ▁res in , ▁or ▁pl astic , ▁often ▁called ▁a ▁therm os et , ▁is ▁a ▁polym er ▁that ▁is ▁irre vers ibly ▁hard ened ▁by ▁cur ing ▁from ▁a ▁soft ▁solid ▁or ▁vis c ous ▁liquid ▁pre pol ym er ▁or ▁res in . ▁C uring ▁is ▁induced ▁by ▁heat ▁or ▁suitable ▁radiation ▁and ▁may ▁be ▁promoted ▁by ▁high ▁pressure , ▁or ▁mixing ▁with ▁a ▁catal yst . ▁He at ▁is ▁not ▁necessarily ▁to ▁be ▁applied ▁extern ally . ▁It ▁is ▁often ▁generated ▁by ▁the ▁reaction ▁of ▁the ▁res in ▁with ▁a ▁cur ing ▁agent ▁( catal yst , ▁hard ener ). ▁C uring ▁results ▁in ▁chemical ▁re actions ▁that ▁create ▁extensive ▁cross - link ing ▁between ▁polym er ▁ch ains ▁to ▁produce ▁an ▁inf us ible ▁and ▁ins ol ub le ▁polym er ▁network . ▁ ▁The ▁starting ▁material ▁for ▁making ▁therm os ets ▁is ▁usually ▁m alle able ▁or ▁liquid ▁prior ▁to ▁cur ing , ▁and ▁is ▁often ▁designed ▁to ▁be ▁m old ed ▁into ▁the ▁final ▁shape . ▁It ▁may ▁also ▁be ▁used ▁as ▁an ▁ad hes ive . ▁Once ▁hard ened , ▁a ▁therm os et ▁cannot ▁be ▁m elt ed ▁for ▁res h aping , ▁in ▁contrast ▁to ▁therm op last ic ▁polym ers ▁which ▁are ▁commonly ▁produced ▁and ▁distributed ▁in ▁form ▁of ▁pel lets