Adhesion of liquid silicone rubber (LSR) polypropylene (PP) composites after storage tests

The objective of this study is the production of liquid silicone rubber (LSR) polypropylene (PP) composites. To create adhesion between LSR and thermoplastics, self-adhesive LSR types are available on the market. However, these materials are not effective for commodity thermoplastics, such as PP and no adhesion can be achieved between these two components. Therefore, the PP surface was activated by means of silicatization (flame treatment). Subsequently, the LSR was applied on the activated PP by an overmolding injection molding process. After sample production a further focus was on post-treatment processes on the adhesive bond. Therefore, the entire composites were temperature stored. Peel tests according to the VDI guideline 2019 were carried out to examine the influence of the temperature storage on the peel resistance. Furthermore, the single components were examined separately by means of thermal, mechanical, and morphological tests to detect influences on the adhesion properties after storage.