Innovative TPV two-phase polymers:: Formulation, morphology formation, property profiles and processing characteristics

An innovative TPV two-phase polymeric system is described. The new TPV is composed of a polypropylene (PP) matrix in which a metallocene-type ethylene/octene copolymer (EO) is dispersed. The EO-copolymers are grafted with vinyl organosilanes, then blended with PP, hydrolyzed and water-crosslinked in a co-rotating, intermeshing twin-screw extruder. The resulting TPV-grades are easy to process into articles showing an attractive range of properties. The advantages are due to blend composition and crosslinking concept. The new TPV's can be processed without pre-drying. Moldings are characterized by excellent surface quality and absence of odor as a result of the innovative use of the EO elastomer and the modified crosslinking concept. They can easily be colored to any desirable-shade. The reduced cost of ingredients is another advantage of the newly developed thermoplastic elastomers. High ultimate strength (sigma(R)) and elongation-at-break (epsilon(R)) values as well as a broad spectrum of different Shore A grades open up many new fields of application. The main focus has been on the automotive applications not least because of very low fogging rates.