Development of a bilayer coating to improve the adhesion between stainless steel and in situ-polymerized poly(methyl methacrylate)

摘要

A bilayer coating was developed that may be applied over a stainless steel surface to enhance the adhesive strength with in situ-polymerized poly(methyl methacrylate). The first layer was an epoxy based on diglycidyl ether of bisphenol A (DGEBA) crosslinked with N-(2aminoethyl)-3-aminopropyltrimethoxysilane (AEAPS). A prereaction and a fast cure were needed to avoid phase separation after the dip coating process. The second layer constituted of an organic-inorganic hybrid formulation synthesized by a sol-gel process. It was based on 2-hydroxyethylmethacrylate (HEMA), 3-methacryloxypropyltrime-thoxysilane (MPMS), and tetraethoxysilane (TEOS). This layer provided silanol groups to react with the methoxysi-produce covalent bonds during the methyl methacrylate polymerization. Stainless steel plaques were successively coated with both layers (about 700 nm per layer), using a dip coating process. Both coated and uncoated plaques were bonded with a 0.55-mm thickness of a two-parts PMMA cement, using the standard geometry to perform single lap-shear strength tests. The average lap-shear strength increased from 3.4 +/- 1.5 MPa for the uncoated metals to 9.7 +/- 1.5 MPa for the plaques coated with the bilayer system. (c) 2007 Wiley Periodicals, Inc.