The Influence of NBR Waste Modified with SiO2/Not Modified on Processability, Physical-Mechanical and Structural Properties of PVC

Abstract

The finished products made of PVC and NBR after the end of the life (waste) are considered harmful, because they do not degrade and thus remain for a long time in the environment. Therefore, there is intense research in order to recycle such materials and reintroduce them into the productive cycle in a new form, without compromising very much their mechanical properties. In the case of rubber recycling, there are currently several methods, from reducing the dimensions to expensive devulcanization processes in order to use them in different thermoplastic matrices. However, the simple reduction of the size of the vulcanized rubber and the mixing with PVC, leads to weak mechanical properties, due to the incompatibility and immiscibility between the phases. Such a composite material was obtained using recycled vulcanized NBR rubber particles (0.35 mm) unmodified/ modified with 10% PDMS, in virgin PVC matrix and waste PVC (50:50) and in the presence of the genioplast additive by the homogeneous mixing technique in the Brabender mixer. The materials experimented were analyzed structurally – FTIR, rheological (torque versus time), from the point of view of processability (flow index) but also mechanically. The analysis of the physico-mechanical values shows that the addition of 10% NBR in the PVC matrix reduces the tensile strength, the 100 and 300% modulus, the elongation at the break, the tear due to their agglomeration, reduce processability (based on the MFR obtained values) but improve the abrasion resistance, an important property of the materials used especially in the footwear industry. However, these types of materials can be used in other applications (automotive, agriculture, etc.) where very high resistances are not required.