Terpene polymerization a binary neodymium-based catalytic system with di--butylmagnesium as a co-catalyst.

The development of materials from renewable resources has been increasing, intending to reduce the consumption of fossil sources, with terpenes being one of the main families that reduce the consumption of isoprene. The study of the binary catalytic system neodymium versatate/dibutyl magnesium (NdV/Mg(-Bu)), for the coordination homopolymerization of β-myrcene and β-farnesene, was carried out analysing different [Nd] : [Mg] ratios (between 4 and 10). Reporting conversions of 92% and 83% at an [Nd] : [Mg] ratio of 8 for polymyrcene (PMy) and polyfarnesene (PFa), respectively, and microstructures comprising 1,4 content above 80% for both polymers (PMy, -59% and PFa, -83%).

Synthesis and Superficial Modification "In Situ" of Copper Selenide (Cu Se) Nanoparticles and Their Antibacterial Activity.

Copper selenide nanoparticles (Cu Se NPs) have received a lot of attention in recent decades due to their interesting properties and potential applications in various areas such as electronics, health, solar cells, etc. In this study, details of the synthesis and characterization of copper selenide nanoparticles modified with gum arabic (GA) are reported. Also, through transmission electronic microscopy (TEM) analysis, the transformation of the morphology and particle size of copper selenide nanoparticles in aqueous solution was studied.

Nanostructured Copper Selenide Coatings for Antifouling Applications.

The accumulation of microorganisms, plants, algae, or small animals on wet surfaces that have a mechanical function causes biofouling, which can result in structural or other functional deficiencies. The maritime shipping industry must constantly manage biofouling to optimize operational performance, which is a common and long-lasting problem. It can occur on any metal structure in contact with or submerged in ocean water, which represents additional costs in terms of repairs and maintenance.

Insights on the Molecular Behavior of Polypropylene in the Process of Ultrasonic Injection Molding.

Product miniaturization is a constant trend in industries that demand ever-smaller products that can be mass produced while maintaining high precision dimensions in the final pieces. Ultrasonic micro injection molding (UMIM) technology has emerged as a polymer processing technique capable of achieving the mass production of polymeric parts with micro-features, while still assuring replicability, repeatability, and high precision, contrary to the capabilities of conventional processing technologies of polymers. In this study, it is shown that the variation of parameters during the UMIM process, such as the amplitude of the ultrasound waves and the processing time, lead to significant modification on the molecular structure of the polymer.

Synthesis of Copper Nanoparticles Stabilized with Organic Ligands and Their Antimicrobial Properties.

In this work, we report the synthesis of copper nanoparticles (Cu NPs), employing the chemical reduction method in an aqueous medium. We used copper sulfate pentahydrate (CuSO·5HO) as a metallic precursor; polyethylenimine (PEI), allylamine (AAM), and 4-aminobutyric acid (AABT) as stabilizing agents; and hydrated hydrazine as a reducing agent. The characterization of the obtained nanoparticles consisted of X-ray, TEM, FTIR, and TGA analyses.

Transparent Low Electrostatic Charge Films Based on Carbon Nanotubes and Polypropylene. Homopolymer Cast Films.

Use of multi-wall carbon nanotubes (MWCNTs) in external layers (A-layers) of ABA-trilayer polypropylene films was investigated, with the purpose of determining intrinsic and extrinsic factors that could lead to antistatic behavior of transparent films. The incorporation of 0.01, 0.

Ultrasound-Assist Extrusion Methods for the Fabrication of Polymer Nanocomposites Based on Polypropylene/Multi-Wall Carbon Nanotubes.

Isotactic polypropylenes (iPP) with different melt flow indexes (MFI) were used to fabricate nanocomposites (NCs) with 10 wt % loadings of multi-wall carbon nanotubes (MWCNTs) using ultrasound-assisted extrusion methods to determine their effect on the morphology, melt flow, and electrical properties of the NCs. Three different types of iPPs were used with MFIs of 2.5, 34 and 1200 g/10 min.