Ecofriendly poly(vinyl alcohol) and coconut shell powder composite films: Physico-mechanical, thermal properties, and swelling studies

Biocompatible Polymer for Self-Humidification

Lung supportive devices (LSDs) have been extensively utilized in treating patients diagnosed with various respiratory disorders. However, these devices can cause moisture depletion in the upper airway by interfering with the natural lubrication and air conditioning process. To remedy this, current technologies implement heated humidification processes, which are bulky, costly, and nonfriendly. However, it has been demonstrated that in a breath cycle, the amount of water vapor in the exhaled air is of a similar quantity to the amount needed to humidify the inhaled air. This research proposes to trap the moisture from exhaled air and reuse it during inhalation by developing a state-of-the-art hydrophilic/hydrophobic polymer tuned to deliver this purpose. Using the atom transfer radical polymerization (ATRP) method, a substrate was successfully created by incorporating poly (N-isopropyl acrylamide) (PNIPAM) onto cotton. The fabricated material exhibited a water vapor release rate of 24.2 ± 1.054%/min at 32 °C, indicating its ability to humidify the inhaled air effectively. These findings highlight the potential of the developed material as a promising solution for applications requiring rapid moisture recovery.

Green composites based on Atriplex halimus fibers and PLA matrix

This work focuses on the potential use of cellulose fibers extracted from Mediterranean saltbush (Atriplex halimus) as a filler in the polymeric matrix. The fully biodegradable composites were prepared from polylactic acid (PLA) as matrix and microcellulose fibers ranging from 0 to 15 wt.%. The influence of the fiber content on the structure, mechanical, thermal, and water absorption properties was evaluated. Mechanical results indicated that fibers acted effectively as reinforcement, increasing the tensile strength and the Young’s modulus of PLA by 25 and 45%, respectively. This is due to the good stress transfer between fibers and matrix through the strong interactions that have been evidenced by Fourier Transform Infrared (FTIR) spectroscopy. The thermogravimetric analysis showed that PLA composites have a slightly lower degradation temperature than the pure PLA, but they still have favorable thermal stability. Water absorption measurements and biodegradability tests showed that the addition of fibers accelerates degradation kinetics and confirm that the prepared composites are an environmentally safe material suited for different applications.

Development of Composites of Highly Filled Phenol Formaldehyde Resin – Coconut (Cocos nucifera) Endocarp Particles

Considering the growing interest in the development of new materials based on renewable materials, this paper presents the results of experiments carried out with high content (80 to 95 %) of coconut endocarp particles in phenol formaldehyde resin for the development of composite material by compression molding. The morphology of the particles and chemical composition and thermal stability of both the particles and the resin were evaluated. Tensile and flexural properties of the composites exhibited significant improvements with increasing resin content, attributed to good bonding between the resin and the particles and the presence of fewer voids in the composites as well as to the microstructural homogeneity, as corroborated by the fractographic studies. The thermal stability of the composites is influenced by the proportion of particles, while the swelling characteristics are affected by the amount of resin. The results taken together suggest that the developed composite can be used for various applications.