Investigation of effect of bio-based additives on the physical and mechanical of properties of polyvinyl chloride synthetic leather

Leather has been used throughout history due to its durability. In recent years, ethical and environmental concerns have increased the importance of synthetic leather. Polyurethane (PU) and polyvinyl chloride (PVC)-based synthetic leathers stand out in furniture, automotive, and fashion sectors with their cost-effectiveness and sustainable properties. Additionally, research on bio-based raw materials, waste, and vegan components supports environmental sustainability. In the synthetic leather industry, new materials and production methods are being developed in this direction. In this thesis, bio-additives such as coffee grounds, grape seeds, and carob flour were incorporated into plastisols used in PVC-based synthetic leather production. Their effects on the rheological behavior of plastisols and the physical properties of PVC sheets were investigated. Samples prepared on a laboratory scale were analyzed using morphological, mechanical, and rheological tests. The results showed that calcium carbonate samples had the most homogeneous structure, while coffee grounds and grape seed additives enhanced polymer-filler interactions. Carob flour samples exhibited microvoids. Mechanical tests revealed the highest Young's modulus in coffee ground samples, while tensile strength was highest in calcium carbonate samples. In the second stage, bio-additive plastisols were applied to fabrics to assess industrial applicability. Tests on color fastness, tear resistance, hydrolysis resistance, and abrasion were conducted. Carob flour samples showed hydrolytic degradation, but no significant negative effects were observed in other additives. The findings suggest that bio-based additive synthetic leathers can be used in furniture, textiles, and other industries. This study highlights the need for innovative solutions to make synthetic leather a more environmentally friendly and competitive alternative to natural leather.