Polymer nanocomposite

About: Polymer nanocomposite is a research topic. Over the lifetime, 8977 publications have been published within this topic receiving 297599 citations.

The impact of the nature of nanofillers on the performance of wood polymer nanocomposites

Abstract: Wood polymer nanocomposites have been prepared from aspen wood using melamine-urea-formaldehyde (MUF) and montmorillonite nanoclay. The nanoparticles were ground with a ball-mill and mixed with the prepolymer to form suspensions that were subsequently impregnated into the wood and in situ polymerized. The influence of the nature of nanofillers and interphase interactions between nanoparticles and MUF on the physical/mechanical properties of the resulting wood polymer nanocomposites was investigated, using SEM, TEM and Electron Probe Micro-Analysis (EPMA) methods. Significant improvements in wood properties, including surface hardness, modulus of elasticity, dimensional stability and water repellence, were obtained with the addition of hydrophobic nanoparticles into the wood. The improved properties could be ascribed to inherent properties as well as better interphase between MUF and nanoparticles, and their co-reinforcement on the wood. Ball-mill treatment favored the dispersion of the nanoparticles into the wood, but broke down functional groups on the hydrophobic nanoclay surface, which was detrimental for the bonding between the nanoparticles and the MUF matrix.

Lattice Monte Carlo Simulations of Chain Conformations in Polymer Nanocomposites

Abstract: Lattice Monte Carlo simulations were performed on monodisperse polymer melts, with DP's ranging from 100 to 400, filled with nanoparticles of sizes comparable to the chain Rg. We critically study the role of the mean distance between these nanofillers on the overall conformation of polymer chains and, more importantly, on the statistics of bridges, dangling ends, loops, and trains. We are motivated to study these issues since it has been suggested that the mechanical behavior of nanocomposites result from the formation of a long-lived transient filler network mediated by the chains. Further, the experimentally observed increase in low frequency, low strain amplitude elastic modulus on the addition of filler is attributed to strongly stretched bridge segments. We find that the overall chain statistics remain Gaussian regardless of filler loading (up to 27 vol %). Short bridges, loops, and tails are strongly stretched, but in a manner that is quantitatively equivalent to the statistics of subchains in a mel...

Polymer nanocomposites with high energy storage densities

Abstract: Dielectric capacitors have been the major enabler for many applications in advanced electronic and electrical power systems because of their capability for ultrafast charging/discharging and ultrahigh power density. The low energy densities of polymer dielectrics used in these capacitors have not been able to meet the ever-increasing demands for compact, reliable, and efficient electrical power systems. Polymer nanocomposites, in which high-dielectric-constant (k) nanofillers are incorporated in the polymer matrix, have been actively pursued. In this article, we begin with two theoretical considerations for concomitantly increasing the dielectric permittivity and breakdown strength of nanocomposites: critical interfacial polarization and local electric-field distribution. In the framework of these considerations, we review recent progress toward polymer nanocomposites with high energy densities based on two approaches: core–shell-structured polymer nanocomposites and dielectric anisotropy. In addition, the potential for the enhanced elastic properties of nanocomposites to improve the dielectric strengths of capacitor films is also discussed.