Improvement of polymeric material adhesion by UV laser and plasma pretreatment

The objective of the presented work was to determine the relationship between acid-base properties and parameters of UV laser and plasma surface pretreatment of polymers to increase their adhesive strength. A further aim of the studies was the preselection of material combinations with good adhesion properties. The ideal exposure modes and characteristics (threshold of ablation, intensity, frequency and number of pulses for UV laser pretreatment; processing power and treatment duration for plasma pretreatment) were determined for optimal modification of the surface properties. For the evidence-based selection of the components to be joined, the surface free energy, its parameters and components, as well as a shortened acidity parameter (modification of the model E. Berger) were determined for acrylic, methacrylate, polyurethane and epoxy adhesives. The surface free energy, its parameters and components were estimated for the high performance polymers polyether ether ketone (PEEK) and polyphenylene sulfide (PPS), the fluoropolymers ethylene chloro trifluoroethylene (ECTFE), perfluoroalkoxy alkane (PFA) and polyvinylidene fluoride (PVDF) and various types of bioplastics like polybutylene succinate (PBS) polyhydroxybutyrate (PHB), polylactide (PLA), and their copolymers.