Effect of heating time below the melting temperature on polyphenylene sulfide adhesive joint development

A long heating time below the melting temperature (Tm) was found to be detrimental to subsequent polyphenylene sulfide (PPS) adhesive joint development above Tm. This was found to be due to curing reactions below Tm and consequent reduced mass flow response above Tm. A high heating rate (small heating time) enhanced the bonding more than a high pressure. The study was conducted by measurement of the contact electrical resistance of the joint, and was supported by calorimetry.