SURFACE-TREATMENT OF FLUORINATED RUBBER WITH TRIAZINE THIOLS AND THEIR PROPERTIES

Fluorinated (FKM) vulcanizates were treated by immersing in an aqueous solution of triazine thiols, NaOH, and onium salts for 15-60 min at 5 0-95-degrees-C (W-Method). Treated FKM vulcanizates further were postc ured in an air oven for 20 h at 200-degrees-C to complete the reaction . The onium salt of triazine thiols were found to be formed by a react ion among the triazine thiols, NaOH, and onium salts and to act as cro ss-linking agents to the surface of FKM vulcanizates. In the acetone s olution of onium salts of triazine thiols, FKM vulcanizates were also treated by immersing for a few minutes at 20-degrees-C and then by hea ting in an air oven for 20 min at 200-degrees-C (A-Method). Triazine t hiols were introduced as crosslinks onto the FKM backbone. The degree of cross-linking in the surface increased by these treatments and the depth of cross-linking reached up to about 40 mum thickness by control of treating conditions. The coefficient of friction in FKM vulcanizat es decreased as a result of the surface treatment up to about 0.5 from 2.6. FKM vulcanizates decreased the tensile strength by these surface treatments because of the generation of cracks on the surface at 50% or 100% elongation. The surface treatment of FKM vulcanizates suppress ed markedly the fixing between FKM vulcanizates and stainless steel at 150-degrees-C. Especially, the A-Method was very effective treating f or retarding the fixing between FKM vulcanizates and metals. (C) 1994 John Wiley & Sons, Inc.