Effect of concentration and temperature in the solution of expanded polystyrene using natural solvents

Abstract

Expanded polystyrene (EPS) is a single-use plastic, with a low level of recycling due to the large volume occupied by its waste, this has generated that a large part of it ends up accumulating in landfills or public spaces, generating environmental problems for communities surrounding. An alternative for its treatment is the use of solvents, however this method has been little studied and the most commonly used solvents are harmful to health and / or the environment. In this project, it was studied how temperature and concentration influence the dissolution of EPS in two natural compounds: limonene and eucalyptus oil, in order to determine the viability of the use of these solvents, for which solubility parameters were compared and tests were carried out. laboratory with EPS residues to which cleaning, grinding, dissolution processes were applied at different temperatures (between 21 ° C and 50 ° C) and concentrations (1:10, 3:10, 1: 2, 3: 4, 1: 1, 1.25: 1 and 1.5: 1) and solvent recovery. It was determined that the viscosity presents an exponential behavior from 42 % concentration and at higher temperature, lower viscosity (µ) and dissolution time; on average the original volume of the EPS can be reduced by 96 %. We can conclude that the solubility parameters (d) and polymer-solvent interaction () for both solvents are favorable for the dissolution of EPS, and are favored with increasing temperature, however the solution in limonene has better miscibility and requires less activation time and energy (Ea).