ADHESION OF LATEX FILMS .1. POLY(2-ETHYL-HEXYL METHACRYLATE) ON GLASS

The adhesion properties of latex films containing various kinds of sur factants were studied on glass by the use of a 180 degrees peel test. The latex polymer was poly(2-ethyl hexyl methacrylate) (P2EHMA). The s urfactants were sodium dodecyl sulfate (SDS), hexadecyl trimethylammon ium bromide (HTAB), hexadecyl pyridinium chloride (HPCl), and ethoxyla ted nonyl phenol containing 10 ethoxy groups (NP10). Peel energy versu s surfactant concentration curves were established. At medium and high peel rates (15-700 mm/min), these curves exhibit a specific shape for each surfactant: a minimum for NP10, a maximum for SDS and HPCl, and a plateau followed by a sharp increase for HTAB. In the case of HPCl-c ontaining films, it was shown that the maximum tended to disappear whe n the peel rate was decreased and at 'zero peel rate' there was no lon ger a surfactant concentration effect on the peel energy. Analysis of the failure surfaces after peeling by FTIR-ATR, XPS, and contact angle measurements led to the conclusion that the locus of failure was also independent of the surfactant concentration. Failure took place at th e top of a surfactant layer located between the substrate and the late x film. The conclusion is that surfactants strongly influence the adhe sion properties of latex films, but in a complex way.