Green Rubber Technology: The Potential of Ophthalmic Lens Waste as a Filler in Styrene–Butadiene Rubber-Based Composites

The article examines the possibility of using ophthalmic lens waste (OLW) as a filler in styrene-butadiene rubber (SBR) composites in varying proportions. It analyzes the impact of OLW on the composites' rheological, structural, morphological, mechanical, and thermal properties. Results show that OLW addition does not significantly alter vulcanization time, leading to thermal savings during processing. The crosslink densities, determined by the swelling method in an organic solvent and the mechanical behavior of the elastomers, increased with the incorporation of OLW, suggesting a filler/polymeric matrix interaction. The Lorenz-Parks model confirmed matrix-filler interaction, although it was insufficient to substantially improve mechanical reinforcement, with OLW mainly acting as a filler. Thermogravimetric tests revealed good thermal stability, but dynamic mechanical analysis indicated reduced damping properties. Spectroscopic analysis indicated the lack of molecular bonding between the polymer and the OLW filler. The study suggests that the optimal OLW content is between 10 and 20 phr, enabling the production of a new composite. Overall, incorporating OLW into vulcanized SBR composites offers a sustainable and cost-effective approach to reusing industrial waste in polymer production, providing an environmentally friendly alternative for the polymer industry.