In this study, poly(vinyl chloride) (PVC) and silica (SiO 2 ) microcomposites and nanocomposites were prepared by melt mixing in a Haake torque rheometer. The fusion and rheological behaviors of PVC/SiO 2 composites were evaluated by means of torque data recorded during processing to investigate the influence of the SiO 2 particle size on these behaviors. It was found that the fusion time and the fusion temperature decreased with the decreasing of SiO 2 particle size, whereas the fusion torque increased with the decreasing of particle size. The PVC/Si-25-nm nanocomposite (PVC including the 25 nm of SiO 2 ) showed the highest apparent viscosity among the PVC/SiO 2 microcomposites and nanocomposites prepared in this study. Scanning electron microscopy results demonstrated that some aggregates, whose sizes about 60-90 nm, were formed when the 25 nm of SiO 2 was used as filler. POLYM. ENG. SCI., 51:1574-

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In this study, imidazolium functionalized poly(vinyl alcohol) (PVA) was synthesized by acetalization and direct quaternization reaction. Afterwards, composite anion exchange membranes based on imidazolium-and quaternary ammonium-functionalized PVA were used for direct methanol alkaline fuel cell applications. 1 H NMR and Fourier transform infrared spectroscopy data indicated that imidazole functionalized PVA was successfully synthesized. Inductively coupled plasma mass spectrometry data demonstrated that the imidazolium structure was efficiently obtained by direct quaternization of the imidazole group. Composite anion exchange membranes were fabricated by application of the functionalized PVA solution on the surface of porous polycarbonate (PC) membranes. Fuel cell related properties of all prepared membranes were investigated systematically. The imidazolium functionalized composite membrane (PVA-Im/PC) exhibited higher ionic conductivity (7.8 mS cm −1 at 30°C) despite a lower water uptake and ion exchange capacity value compared to that of quaternary ammonium. In addition, PVA-Im/PC showed the lowest methanol permeation rate and the highest membrane selectivity as well as high alkaline and oxidative stability. Dynamic mechanical analysis results reveal that both composite membranes were mechanically resistant up to 10 7 Pa at 140°C. The superior performance of imidazolium functionalized PVA composite membrane compared to quaternary ammonium functionalized membrane makes it a promising candidate for direct methanol alkaline fuel cell applications.

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The effects of calcium carbonate (CaCO3) particle size on the fusion and rheological behaviors of rigid poly(vinyl chloride) (PVC) composites prepared in a Haake torque rheometer were investigated by means of torque data recorded during processing. Increasing the number of particles in the same blend volume by decreasing the particle size resulted in increasing frictional forces. This increase led in turn to increased fusion torque and decreased fusion time and temperature. The power‐law‐index values of the composites increased with decreasing particle size except for 25‐nm CaCO3. The viscosities of all composites were found to decrease with shear rate; therefore, high pseudoplasticity was observed. At a particular rotor speed, viscosity of the composites decreased with decreasing particle size except for 25‐nm CaCO3. The overall results showed that the particle size of CaCO3 altered the fusion characteristics and rheological behavior of PVC. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers

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Here, it was aimed to modify the surface of NF90 with layer by layer (LbL) blended poly(allylamine hydrochloride) (PAH)‐chitosan (CHI) and poly(acrylic acid) (PAA) with/without functionalized multiwalled carbon nanotube (fMWCNT) for reverse‐osmosis applications. Using Quartz Crystal Microbalance Dissipation monitoring, it was observed that PAH‐CHI/PAA LbL films grew linearly after a few bilayers and no LbL film degradation occurred during synthetic seawater treatment. Thermal degradation of all LbL blended membranes was similar. NF90 had a heterogeneous surface while the surface of LbL blend membranes exhibited some agglomerations due to the polyelectrolyte (PE) complex formation and fibrillary appearance depending on the use of fMWCNT. [(PAH50‐CHI50/(PAA‐fMWCNT)]30 indicated the highest flux with 14.5 L m2 h−1 at 40 bar. The sodium and chlorine ion rejections were 75% and 87%, respectively, for the same membrane. The use of fMWCNT led to a significant enhancement in flux with a slight decay in ion rejections. On the other hand, chlorine ion rejection of [(PAH50‐CHI50/(PAA‐fMWCNT)]30 decreased by 25% at 40 bar while 60 and 90 bilayers of [(PAH50‐CHI50/(PAA‐fMWCNT)] disintegrated after NaOCl treatment. Briefly, the flux and ion rejections of the LbL blended membranes can be controlled depending on the use of fMWCNT and different PE couples without multilayer decomposition against synthetic seawater. POLYM. ENG. SCI., 60: 341–351, 2019. © 2019 Society of Plastics Engineers

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