High-performance adhesives based on maleic anhydride-g-EPDM rubbers and polybutene for laminating cast polypropylene film and aluminum foil

Abstract

The adhesion between aluminum (Al) foil and cast polypropylene (CPP) film laminated with mixtures of amorphous- and crystalline-maleic anhydride-grafted ethylene-propylene-diene monomer (MAH-g-EPDM) rubbers and highly reactive polybutene (HRPB) as the adhesives was investigated. Specifically, the HRPB was used as an adhesion promoter of the MAH-g-EPDM rubbers and CPP as well as a compatibilizer of two kinds of MAH-g-EPDM rubbers having limited miscibility. To introduce strong chemical bonds between the MAH-g-EPDM rubbers and Al foil, the surface of Al foil was treated with 3-aminopropyl triethoxysilane (APTES). The weak adhesion between Al foil and MAH-g-EPDM rubbers was improved by imidization between the amine groups (-NH2) of APTES and the maleic anhydride groups (MAH) of MAH-g-EPDM rubbers. The effects of the composition of adhesives, tempering time and adhesive thickness were also studied to optimize the adhesion of the CPP/Al foil laminates. We concluded that MAH-g-EPDM rubber based adhesives containing HRPB can be applied for the lamination of Al foil and CPP films to satisfy the requirements of high-performance packaging materials for various purposes.