Hydrophobic papers based on cellulose coated with recycled polystyrene

Polystyrene (PS) is a synthetic polymer mainly produced in the expanded form (expanded polystyrene, EPS), commercially known as Styrofoam™, which is composed by only 2 wt% of PS. The mechanical and thermal recycling of EPS are not favored due to low density and release of toxic gases to the environment, respectively. The chemical recycling is an alternative approach for the EPS recycling because the dissolution in a solvent prevents the polymer degradation and there is no gas release into the environment. The use of d-limonene extracted from orange peel as a solvent is attractive since it comes from a renewable source and reduces about 95% of the original EPS volume. The resulting solution can be tailored to fabrication of hydrophobic surfaces, such as hydrophobic papers. In this way, different EPS solutions were acquired through the dissolution of EPS packages in d-limonene, followed by the application into cellulose surface using the airbrush technique, as show in figure 1. The concentrations of EPS solutions used were 10%, 15% and 20%. All samples were characterized by contact angle, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and vibrational infrared spectroscopy (IR). Initial results show that the contact angle increases as the concentration of the EPS solution increases, indicating that there is an increase in the hydrophobicity of the cellulose surface.