Utilization of polypropylene sterilized via ultraviolet C radiation as a potential compatibilizer for PP/EVOH

• Grant number: 24/09498-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2024
• End date: February 28, 2025
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Lucas Henrique Staffa
• Grantee: Eric Dindyu Chigusa
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Plastic products are used in a wide variety of biomedical devices. Due to the SARS-CoV-2 pandemic and the use of single-use plastics, the amount of solid waste generated in this sector is enormous. Sterilization and disinfection are physical-chemical processes that not only eliminate microbial life on the surface of materials and objects but also induce significant changes to the plastic material. Repeated sterilization cycles can lead to the weakening of the polymer and alterations in its color and shine. However, there is also a potential for chemical functionalization of the plastic, with the formation of polar carbonyl-based chemical groups. These make the sterilized plastic in UV-C (96 and 192h) more polar, making it a type of active surface capable of making multicomponent mixtures compatible, such as composites and/or polymer blends. In this context, the aim is to use sterilized plastic as a compatibilizer in polymer blends of PP and ethylene vinyl alcohol copolymer (EVOH), originating, for example, from the mechanical recycling of multilayer packaging. To achieve this, sterilization will be simulated by exposing PP films to Ultraviolet C irradiation. This will be incorporated at 1, 3, and 5% by mass. Aspects of interfacial adhesion will be evaluated via Scanning Electron Microscopy (SEM) and oscillatory rheometry to estimate interfacial tension via Palierne Model, the most tangible thermodynamic parameter for studying adhesion and interfacial integrity. Additionally, the objective will be to examine the impact on thermal transitions and crystallinity content of polymer phases using Differential Scanning Calorimetry (DSC). Moreover, these mixtures will undergo tensile tests to assess the effect of compatibility on the mechanical behavior of the blend. This project aims to develop an effectively compatible multicomponent material, with the goal of repurposing non-contaminated solid plastic waste as potential physical compatibilizers.