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In this work, nanocomposites of poly (m-xylene diamide) (MXD6) with dodecaphenyl polyhedral oligomeric silsesquioxane (POSS), montmorillonite (MMT) and their combination (MMT-POSS) were produced by meltcompounding and their structure- property relationships were established. The montmorillonite was found to be homogeneously dispersed affording intercalated disordered structures whilst the distribution and dispersion of the POSS was rather skewed with the presence of phase separated crystalline aggregates of up to several hundred nanometers. Significant differences in properties were observed depending on the type of nanoscale filler present in the nanocomposites. The montmorillonite provided some improvements in stiffness and dynamic response of MXD6. POSS on the other hand improved the ductility of MXD6 and had a plasticizing effect. It has been suggested that there might be a lubricating action at the interface inducing better molecular motion between polymer chains of MXD6. By combining MMT and POSS, the properties of the corresponding nanocomposites were found to be intermediate. The thermal stability of MXD6 was enhanced in the nanocomposites although a negative deviation from the theoretical model was observed when POSS was present in the nanocomposites. This observation underlies some antagonistic effects which have been attributed to the presence of catalytic benzene radicals during thermal degradation. POLYM. ENG. SCI., 52:1402-1412, 2012. © 2012 Society of Plastics Engineers, INTRODUCTION The mechanical reinforcement of engineering polymers with micrometric size tillers has played an important role in the plastic industry. The changes in mechanical properties are however dependant on many [...]

This study evaluates the effect of plasma surface functionalization of reduced graphene oxide particles on the processing characteristics and homogeneity of dispersion of a bisphenol A‐(epichlorhydrin) epoxy matrix and amine‐based hardener with varying weight fractions from 0.00 to 1.50 wt%. It was observed that amine‐functionalized reduced graphene oxide leads to a more drastic viscosity increase of up to 18‐fold of the uncured suspensions and that its presence influences the conversion rates of the curing reaction. Optical microscopy of thin sections and transmission electron microscopy analysis showed that a more homogeneous dispersion of the particles could be achieved especially at higher weight fractions by using an appropriate surface functionalization. This knowledge can be used to define suitable processing conditions for epoxies with amine‐based hardeners depending on the loading and functionalization of graphene‐related particles. [ABSTRACT FROM AUTHOR]

Film uniformity is an issue in many deposition processes, especially in substrates with elongated lateral dimensions such as fibers. In this study, a plasma chamber was designed with dual electrodes to improve the uniformity of plasma polymer films. Plasma‐polymerized acrylic acid films were deposited via single‐electrode or double‐electrode configurations onto silicon wafer pieces placed at the center of the chamber to mimic the potential position of a fiber. A radial and spatial map of film chemistry and thickness throughout the chamber was determined which demonstrated improved radial uniformity and film stability using the dual‐electrode configuration, thus highlighting the importance of spatial characterization when designing a reactor for the coating of three‐dimensional objects such as fibers. [ABSTRACT FROM AUTHOR]