A REACTIVE ACRYLIC ADHESIVE FOR BONDING POLYOLEFINS

An acrylic adhesive was developed for forming strong, water resistant structural joints with polyolefins. This two-component, lightly crossl inked, methyl methacrylate (MMA) based adhesive consisted of an anaero bic curing system in one part with a copper (II) salt catalyst in the other. Bonds formed with low density polyethylene (LDPE) resulted in s ubstrate failure upon block shear testing throughout the open time of the adhesive (45 min). The interdiffusion of the monomers into the sub strates, and their subsequent polymerization was followed using severa l infrared spectroscopy (IR) techniques. The interphase of mixed LDPE and adhesive was determined to be as thick as 1.7 mm using IR microsco py. It was concluded that the strong adhesion in the aforementioned jo ints was the result of the interpenetration of the adhesive into the s ubstrates.