Application of solvent-based dissolution for the recycling of polyvinylchloride flooring waste containing restricted phthalate plasticizers

The applicability of a new recycling method for extracting contaminants from polymers, dissolution-based recycling, was tested on a polyvinylchloride equipped with diethylhexyl phthalate, benzylbutyl phthalate, di-isobutyl phthalate, di-n‑butyl phthalate, originating from post-consumer flooring waste. Due to European restrictions on these ortho-phthalate diester-based plasticizers, the mechanical recycling of plasticized polyvinylchloride is no longer feasible. In this study, we have shown that dissolution and consecutive purification of the polymer eliminate 99.9 % of diethylhexyl phthalate's initial concentration at the laboratory scale. The impact of different process parameters, e.g., temperature, agitation, and extraction kinetics, have been tested. The findings were transferred to a technical scale of 5 kg/d, using a multi-step extraction in counter-flow mode. An elimination of 99.4 % of diethylhexyl phthalate initial concentration has been achieved, which fulfills legal requirements. These promising results showed the technical feasibility and served as a preliminary stage for further up-scaling to technical readiness level 6.