Fine dispersed blends for compatibilizers for laminates of immiscible polymers

Blends of high-density polyethylene (HDPE) and isotactic polypropylene (iPP ) are used to increase the strength of adhesive bonds between the immiscibl e polymers HDPE and iPP. Melt blended as well as solution blended material is examined for its suitability to compatibilize the interface between the bonded members. Two standard test methods, the T-peel test and the tensile test, are applied to determine the strengths of adhesive joints. Laminated samples for the peel-tests as well as specimens subjected to the tensile te sts were prepared at a temperature exceeding the melting temperature of bot h homopolymers. TEM and LVSEM examinations were performed for characterizin g the morphology of the interface with the aim to determine the parameters which significantly influence the blends' adhesive properties. The bonding strengths obtained with the blended material are discussed with respect to the morphologies of the interfaces, the degree of dispersion in the blend, and the bonding mechanisms. (C) 2000 Kluwer Academic Publishers.