Improvement of autohesive and adhesive properties of polyethylene plates by photografting with glycidyl methacrylate

Abstract Glycidyl methacrylate (GMA) was photografted with the low‐ and high‐density polyethylene (LDPE and HDPE) plates to provide their surfaces with autohesive and adhesive properties. The chemical composition and wettability of the GMA‐grafted LDPE and HDPE (LDPE‐g‐PGMA and HDPE‐g‐PGMA) plates remained constant above full coverage of the surfaces with grafted PGMA chains. Autohesive strength obtained with 1,4‐dioxane as a good solvent of PGMA increased with an increase in the grafted amount and substrate breaking was observed at the grafted amount of 117 μmol/cm2. The grafted amount at substrate breaking was decreased by increasing the temperature and load during heat pressing. Adhesive strength was effectively enhanced by use of multi‐functional amine compounds because of the increase in the reaction between primary or secondary amine groups and epoxy groups appended to the grafted PGMA chains. In addition, the decrease in the amine compound concentration and the increase in the number of amino groups in the amine compounds used led to the decrease in the grafted amounts at substrate breaking. Substrate breaking occurred at lower grafted amounts for the HDPE‐g‐PGMA plates than for the LDPE‐g‐PGMA plates because the location of the photografting was restricted to the outer surface region for the HDPE plate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 493–500, 2007