RESUMEN
The cure kinetics of various epoxy resin mixtures, comprising a bisphenol epoxy, two epoxy modifiers, and two hardening agents derived from cardanol technology, were investigated through differential scanning calorimetry (DSC). The development of these mixtures aimed to achieve epoxy materials with a substantial bio-content up to 50% for potential automotive applications, aligning with the 2019 European Regulation on climate neutrality and CO2 emission. The Friedman isoconversional method was employed to determine key kinetic parameters, such as activation energy and pre-exponential factor, providing insights into the cross-linking process and the Kamal-Sourour model was used to describe and predict the kinetics of the chemical reactions. This empirical approach was implemented to forecast the curing process for the specific oven curing cycle utilised. Additionally, tensile tests revealed promising results showcasing materials' viability against conventional counterparts. Overall, this investigation offers a comprehensive understanding of the cure kinetics, mechanical behaviour, and thermal properties of the novel epoxy-novolac blends, contributing to the development of high-performance materials for sustainable automotive applications.
RESUMEN
The automotive industry is always seeking novel solutions to improve the durability and the performance of textile materials used in vehicles. Indeed, especially after the coronavirus pandemic, antibacterial treatments have gained interest for their potential of ensuring cleanliness and safety toward microbial contamination within vehicles. This study gives a panoramic view of the durability of antibacterial treatments applied on textile materials in the automotive industry, focusing on their performance after experiencing accelerated aging processes. Two different textile materials, a fabric and a synthetic leather, both treated with antibacterial agents, were tested according to ISO 22196 and ISO 20743 standards, respectively, using two model microorganisms, Escherichia coli and Staphylococcus aureus. The impact of mechanical, thermal, and solar aging on the antibacterial properties has been evaluated. In addition, scanning electron microscope (SEM) analysis was performed to investigate the surface morphology of the materials before and after aging. Furthermore, contact angle measurements were conducted. The results suggest that neither mechanical nor thermal aging processes determined diminished antibacterial action. It was determined, instead, that the most damaging stressor for both textile materials was UV aging, causing severe surface alterations and a reduction in antibacterial activity.
RESUMEN
Polymer light-emitting diodes (PLEDs) have attracted growing interest in recent years for their potential use in displays and lighting fields. Nevertheless, PLED devices have some disadvantages in terms of low optoelectronic efficiency, high cost, short lifetimes and low thermal stability, which limit their final applications. Huge efforts have been made recently to improve the performances of these devices. The addition of inorganic or hybrid organic-inorganic nanoparticles to the light-emitting polymers, for example, allows their thermal stability and electroluminescent efficiency to be increased. Following this approach, novel PLED devices based on composite films of PPV-derivative copolymer (commercial name Super Yellow, SY) and octaisobutil POSS, were developed in this study. The device containing Super Yellow loaded with 1 wt% of POSS showed higher efficiency (ca. +30%) and improved lifetime in comparison to PLED prepared with the pure electroluminescent polymer. The PLED devices developed in this study are suitable candidates for automotive dashboards and, in general, for lighting applications.