Additives for the cure with peroxides of fluoroelastomers containing bromine or idodine to reduce alkylhalo emissions

A method of reducing toxic emissions of alkylhalo compounds during curing of fluoroelastomers containing bromine and/or iodine cure sites, which comprises;

• i) preparing a curable fluoroelastomer mixture containing at least one fluoroelastomer having bromine and/or iodine cure sites and containing an aliphatic, cycloaliphatic or saturated or unsaturated alkylaromatic organic peroxide;
• ii) adding to the fluoroelastomer mixture from 0.1 to 3 parts by weight of an additive for reducing toxic emissions of alkylhalo compounds from the curable mixture, on curing, based on 100 parts by weight of a fluoroelastomer, comprising at least one compound selected from the group consisting of:
• a) benzothiazole and derivatives thereof of the formula:
• ##STR34## wherein:
• X represents H, --SH, ##STR35## b) maleamide derivatives of the general formula:
• ##STR36## wherein:
• A=H, and T represents --OH;
• R represents H, alkyl with 1 to 6 carbon atoms, halogen or --NO.sub.2
• c) thiuram derivatives of the formula:
• ##STR37## wherein:
• Y represents ##STR38## R.sup.1 represents alkyl with 1 to 4 carbon atoms, d) diphenylguanidine derivatives of the formula:
• ##STR39## wherein R.sup.2 represents H, alkyl with 1 to 6 carbon atoms;
• and
• e) maleic anhydride, diaryl-formamide and derivatives of diazo and triazodicyclodecenes;
• and
• iii) curing the mixture.