Poly(acrylate/epoxy) hybrid adhesives for low‐surface‐energy plastic adhesion

The formulation, polymerization, and performance of a new class of low‐surface‐energy adhesives for plastics are described. The polymerization involves the simultaneous room‐temperature polymerization of polyoxirane monomers in an acrylic monomer phase. The polymerization of the acrylic phase and adhesion promotion to plastics are catalyzed after the decomplexation and oxidation of trialkylborane–amine complexes. The polymerization of the epoxy phase is catalyzed with a Lewis acid such as BF₃, ZnCl₂, or SnCl₄ complexed with ether or amine. This article explores the resulting adhesives as a function of the epoxy monomer functionality, concentration, solubility in the acrylic monomer, Lewis acid catalyst concentration, phase crosslinking, and postprocessing thermal history. The adhesive morphology exhibits a finely dispersed epoxy phase strongly interacting with the major acrylic phase resulting from a nucleation‐and‐growth phase‐separation mechanism. Excellent adhesion to plastics, including polyethylene, polypropylene, poly(tetrafluoroethylene), poly(ethylene terephthalate), and nylon, is achieved with a much higher thermal performance than that achievable with acrylic polymers alone. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 989–998, 2007