Assessment of the Ageing and Durability of Polymers

The Influence of Hybridization of Epoxy-Glass Laminates Modified with Metal Oxides and Graphite Particles

This study examined the impact of hybridization on the mechanical properties of glass-epoxy laminates by incorporating metal oxides and graphite particles into the resin matrix. Basic mechanical tests were conducted, followed by accelerated thermal aging tests. Results showed an increase in bending strength ranging from 12% to almost 30% depending on the used additive. Static tensile tests indicated a 10% increase in strength for materials modified with flake graphite. Accelerated aging tests resulted in a 20% decrease in elastic modulus and 10% decrease in tensile strength. Additives did not improve tensile strength but increased stiffness by 30% for laminates with flake graphite. Fatigue and conductivity tests were also performed, revealing enhanced thermal conductivity and reduced impedance in materials modified with graphite flakes. The study suggests that additives can enhance the mechanical properties of glass-epoxy laminates, making them suitable for applications in automotive and aerospace industries.

Enhancing Footwear Safety for Fall Prevention in Older Adults: A Comprehensive Review of Design Features

BACKGROUND

Falls are a global concern affecting people of all ages; however, older adults are particularly vulnerable to age-related factors and foot-related issues. Footwear is critical for preventing falls, as it provides stability and protection against slips, trips, and falls (STFs). However, a significant gap exists in the systematic exploration of the safety aspects of footwear design for fall prevention in older adults.

METHODS

This comprehensive review applied a meticulous search strategy encompassing prominent databases, including Google Scholar, ScienceDirect, SCOPUS, MEDLINE, ResearchGate, and PubMed. This review synthesized and analyzed existing research to bridge knowledge gaps and provide insights into optimal footwear choices for older adults in terms of design features such as fit, fixation, heel height, collar height, slip resistance, and sole/insole hardness.

RESULTS

The results underscore the importance of specific design features for preventing falls among older adults. A proper fit, secure fixation, appropriate heel and collar heights, slip resistance, and sole/insole hardness significantly contributed to fall prevention. These findings offer valuable guidance for optimizing footwear designs to enhance comfort, stability, and safety in the daily lives of older individuals.

CONCLUSION

This comprehensive review fills a critical knowledge gap regarding the safety of footwear designs for fall prevention in older adults. The identified design features play a vital role in reducing the risk of falls and offer practical recommendations for the development of safer footwear. Ultimately, this study contributes to the existing knowledge base and supports efforts to prevent STFs in older adults through improved footwear design.

Antioxidant Potential of Santowhite as Synthetic and Ascorbic Acid as Natural Polymer Additives

A wide variety of additives are used to improve specific characteristics of the final polymeric product. Antioxidant additives (AAs) can prevent oxidative stress and thus the damage of polymeric materials. In this work, the antioxidant potential and thus the applicability of Santowhite (SW) as synthetic and ascorbic acid (Asc) as natural AAs were explored by using computational tools. Two density functional theory (DFT) methods, M05-2X and M06-2X, have been applied in combination with the 6-311++G(2d,2p) basis set in gas phase. Three antioxidant mechanisms have been considered: hydrogen atom transfer (HAT), single electron transfer-proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET). Bond dissociation enthalpy (BDE), ionization potential (IP), proton dissociation enthalpy (PDE), proton affinity (PA), and electron transfer enthalpy (ETE) have been computed for each potential hydrogen donor site. The results indicate that the antioxidant potential of Asc is higher than SW. Furthermore, some of the C-H bonds, depending on their position in the structures, are potent radical scavengers, but O-H groups are more prone to donate H-atoms to free radicals. Nonetheless, both additives can be potentially applied to safeguard common polymers and prohibit oxidative stress-induced material deterioration.