Effect of interfacial enhancing on morphology, mechanical, and rheological properties of polypropylene-ground tire rubber powder blends

In this work, polypropylene (PP)-ground tire rubber (GTR) blends are prepared by means of melt-extrusion process using a co-rotating twin screw extruder. The influences of types of compatibilizers and crosslinkers on the interfacial interaction state, mechanical and rheological properties of PP-GTR blends are investigated systematically. Particularly, quantitative nano mechanic technique of atom force microscope was employed to examine the change in thickness of the interfacial transition layer between PP and GTR phase with variety of compatibilizer and crosslinker types. Results indicated that styrene-b-poly(ethylene-ethylene/propylene)-b-polystyrene (SEEPS) and peroxide are optimal compatibilizer and crosslinker for interfacial interaction enhancement, respectively. The resultant PP-GTR blend possesses tensile strength of 14.5 MPa, elongation at break of 307%, and permanent set of 16%. It was expected that reaction activities of the crosslinker with GTR and SEEPS would have a significant influence on the agglomeration of GTR particles and the interaction between PP and GTR phase. (C) 2017 Wiley Periodicals, Inc.