Manufacturing and Characterization of Environmentally Friendly Wood Plastic Composites Using Pinecone as a Filler into a Bio-Based High-Density Polyethylene Matrix

The use of wood plastic composites (WPC) is growing very rapidly in recent years, in addition, the use of plastics of renewable origin is increasingly implemented because it allows to reduce the carbon footprint. In this context, this work reports on the development of composites of bio-based high density polyethylene (BioHDPE) with different contents of pinecone (5, 10, and 30 wt.%). The blends were produced by extrusion and injection-molded processes. With the objective of improving the properties of the materials, a compatibilizer has been used, namely polyethylene grafted with maleic anhydride (PE-g-MA 2 phr). The effect of the compatibilizer in the blend with 5 wt.% has been compared with the same blend without compatibilization. Mechanical, thermal, morphological, colorimetric, and wettability properties have been analyzed for each blend. The results showed that the compatibilizer improved the filler–matrix interaction, increasing the ductile mechanical properties in terms of elongation and tensile strength. Regarding thermal properties, the compatibilizer increased thermal stability and improved the behavior of the materials against moisture. In general, the pinecone materials obtained exhibited reddish-brown colors, allowing their use as wood plastic composites with a wide range of properties depending on the filler content in the blend.

Structure-Function Relationship of the Disintegrin Family: Sequence Signature and Integrin Interaction

Disintegrins are small cysteine-rich proteins found in a variety of snake venom. These proteins selectively modulate integrin function, heterodimeric receptors involved in cell-cell and cell-matrix interaction that are widely studied as therapeutic targets. Snake venom disintegrins emerged from the snake venom metalloproteinase and are classified according to the sequence size and number of disulfide bonds. Evolutive structure and function diversification of disintegrin family involves a stepwise decrease in the polypeptide chain, loss of cysteine residues, and selectivity. Since the structure elucidation of echistatin, the description of the structural properties of disintegrins has allowed the investigation of the mechanisms involved in integrin-cell-extracellular matrix interaction. This review provides an analysis of the structures of all family groups enabling the description of an expanded classification of the disintegrin family in seven groups. Each group presents a particular disulfide pattern and sequence signatures, facilitating the identification of new disintegrins. The classification was based on the disintegrin-like domain of the human metalloproteinase (ADAM-10). We also present the sequence and structural signatures important for disintegrin-integrin interaction, unveiling the relationship between the structure and function of these proteins.

Effects of nano reinforcing/matrix interaction on chemical, thermal and mechanical properties of epoxy nanocomposites

This article investigates the impact of addition various types of nanoparticles with different structural, dimensional, and morphological properties on the interphase region formed between the particle/matrix and the curing behavior of the epoxy affect the nanocomposite material properties. For this purpose, epoxy nanocomposites (NCs) were produced by adding multi-walled carbon nanotube (MWCNT) and alumina (Al2O3) nanoparticles (NPs) into the epoxy matrix at different rates (0.5–2.0 wt.%). The effects of the particle/matrix interaction on the properties of the composite have been revealed by chemical, thermal, mechanical analyzes and microstructure investigations. An increase in the absorption density, which reveals the physical interaction of nanoparticles with the epoxy matrix, was observed in Fourier-transform infrared spectroscopy. Absorption vibration peak intensities in nanocomposite samples were at most 1.0 wt.% Al2O3 and 1.25 wt.% CNT added nanocomposites. It was observed that the Tg value increased depending on the number of nanoparticles. The addition of Al2O3 increased Tg values more than CNT. Besides, the mechanical properties of NCs were determined by tensile tests. The highest increase in mechanical properties was achieved by adding 1.25 wt.% CNT and 1.0 wt.% Al2O3, respectively. Mechanical properties tended to decrease at higher addition rates. The shape, size, amount, and distribution of nanoparticles added into the epoxy matrix directly affected the NCs' properties. It has been determined that homogeneously dispersed spherical Al2O3 nanoparticles are more effective than fiber-shaped CNTs in the properties of NCs.