Evaluation of the Processing Method in the Catalytic Regeneration of Polymer Blends of PP/EVOH with Organometallic Additives

• Grant number: 23/11884-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2023
• End date: November 30, 2024
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Lucas Henrique Staffa
• Grantee: Kenzo Akaki Zaniolo
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Multi-resin polymeric materials, such as multi-layer packaging, face greater recycling and roundness challenges than conventional homopolymers. In thermomechanical recycling of these products, polymeric blends are formed. Due to the multi-component complexity, it is essential to use complementary approaches to conventional recycling, including compatibilization methods. However, given the degraded character of the post-industrial and/or post-consumer multi-resin material, the inclusion of conventional compatibilizers (block or maleated copolymers) may not be enough to ensure the restoration of physical and mechanical properties, nor to enable the circularity of the recycled material properly. The use of specialized additives capable of functionalizing one or more phases of the mixture with organometallic monolayers, in order to enable the formation of a "repolymerization" bed of the degraded chains through in situ metallocene-type catalysis, emerges as a promising strategy. In this way, polymeric blends of recycled polypropylene/ethylene-vinyl alcohol copolymer (PPr/EVOH) of droplet-matrix morphology (80/20% by mass) with organometallic additives based on neoalkoxy titanate (1, 1, 5 and 3% by mass) will be studied, aiming at the restoration of physical and mechanical properties through the repolymerization of previously degraded polymeric chains. Here, two methods of incorporation will be analyzed: (i) thermokinetic, in a "Drais" type homogenizer, with low temperature and high shear rate scenario and (ii) thermomechanical, in a corotational twin-screw, in a high temperature and lower shear rate scenario. This project focuses on the recycling and circularity of multicomponent materials and is expected to contribute to increasing the use of recycled material, envisioning the reuse of recycled material as a major phase in new products, establishing consonance with the new perspectives of regulatory agencies in the packaging market.