The Influence of the Polymeric Compatibiliser on the Impact Strength and Physicomechanical Properties of PP/NBR Composites Produced by Reactive Extrusion using a Peroxide Modifying System

Abstract

In order to improve the balance of flow, impact strength, and physicomechanical properties of polypropylene/nitrile butadiene rubber composites of structural designation, we investigated the possibility of using two complementary approaches in the process of manufacturing the composites. Firstly, this involves the introduction into the composition of these composites of special polymeric compatibilisers based on maleinised polypropylene with additions of elastomers of different nature. Secondly, it involves the use of the method of dynamic vulcanisation in the process of reactive extrusion of a PP/BNKS-18AMN blend with a peroxide modifying system including as a coagent a complex of polar vinyl monomer (maleic acid polyester and ethylene glycol) with aramine industrial antioxidant Diafen FP. Determination of the principal physicomechanical characteristics of the composites revealed that only the combined use of these two methods of modification makes it possible to achieve a significant shift in the level of impact strength of PP/NBR composites without adversely affecting other indices, with control of the flow of the end products. Here, the most effective compatibilisers were maleinised blends of polypropylene with non-polar elastomers: ethylene–octene copolymer (Engage 8842) and ternary ethylenepropylene rubber (Royalene 563). It is assumed that a probable cause of the improvement in properties of the polymer blends is the considerable increase in the degree of dispersion of the rubber phase of the NBR in the polypropylene matrix under the action of the modification processes described above.