Study on compatibilization of EPDM/PP TPV

Both the methylolphenolic-grafted polypropylene (PP-g-MP) and maleic acid-grafted ethylene octane copolymer (EOC -g- MAH) were used to improve the compatibility of EPDM/PP thermoplastic vulcanizate(TPV), and their effect on the mechanical properties, phase structure and rheological property of TPV were studied. PP-g-MP increased modulus at 100% and tensile strength of TPV but decreased elongation at break, while EOC-g-MAH increased tensile strength and elongation at break of TPV but decreased modulus at 100%, furthermore, the higher the graft ratio of EOC-g-MAH, the higher the tensile strength and elongation at break of TPV. By phase contrast microscope photographs of TPV, the addition of compatibilizing agent (preferably EOC-g-MAH) could help to produce the fine and uniform disperse of vulcanizated rubber. As a result, EPDM/PP blends were well compatibilized by interactions between methylolphenolic-crosslinked EPDM and EOC-g-MAH. TPV showed better shear sensitivity.