From Disposal to Technological Potential: Reuse of Polypropylene Waste from Industrial Containers as A Polystyrene Impact Modifier

• Main Authors: Carlos Bruno Barreto Luna, Danilo Diniz Siqueira, Eduardo da Silva Barbosa Ferreira, Wallisson Alves da Silva, Jessika Andrade dos Santos Nogueira, Edcleide Maria Araújo
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Sustainability
• Subjects: sustainable development; polypropylene; reuse; impact modifier; polystyrene
• Online Access: https://www.mdpi.com/2071-1050/12/13/5272

The practice of recycling over the years has been increasingly encouraged, with the aim<br />being the manufacturing of materials that contribute to sustainable development. In light of this,<br />the present work evaluated the potential of mixtures of polystyrene (PS)/recycled copolymer<br />polypropylene (PPr), using styrene‐(ethylene/butylene)‐styrene (SEBS) as a compatibilizing agent.<br />Initially, the mixtures were prepared in a co‐rotational twin‐screw extruder, and, afterwards, the<br />extruded granules were molded by injection. The properties of torque rheometry, impact strength,<br />tensile properties, differential scanning calorimetry (DSC), heat deflection temperature (HDT), and<br />scanning electron microscopy (SEM) were evaluated. The formulation PS/PPr/SEBS (70/20/10 %wt.)<br />demonstrated an increase in viscosity, corroborating with an increase of 123% and 227% in the<br />elongation at break and impact strength, respectively, compared to neat PS. Though the elastic<br />modulus and tensile strength suffered losses, the reduction was not drastic. Furthermore, the<br />addition of a semi‐crystalline recycled material in the amorphous matrix (PS) contributed to an<br />increase in thermomechanical strength, as seen in the HDT. The morphology revealed that SEBS is<br />effective in making PS/PPr mixtures compatible because the dispersed phase is well adhered to the<br />PS matrix and promotes greater morphological stability. Thus, it is possible to add value to<br />discarded material and reduce the costs of the final product, which can reduce pollution.