Search results for "Acrylonitrile"
showing 10 items of 67 documents
Gas Barrier, Rheological and Mechanical Properties of Immiscible Natural Rubber/Acrylonitrile Butadiene Rubber/Organoclay (NR/NBR/Organoclay) Blend N…
2020
In this paper, gas permeability studies were performed on materials based on natural rubber/acrylonitrile butadiene rubber blends and nanoclay incorporated blend systems. The properties of natural rubber (NR)/nitrile rubber (NBR)/nanoclay nanocomposites, with a particular focus on gas permeability, are presented. The measurements of the barrier properties were assessed using two different gases—O2 and CO2—by taking in account the blend composition, the filler loading and the nature of the gas molecules. The obtained data showed that the permeability of gas transport was strongly affected by: (i) the blend composition—it was observed that the increase in acrylonitrile butadiene rubber compon…
Mechanism of co-pyrolysis of coal-tar pitch with polyacrylonitrile
2003
Abstract Co-pyrolysis of coal-tar pitch with polyacrylonitrile (PAN) and PAN oxidized in air at 300 °C was studied as a possible way of manufacturing of carbonaceous materials enriched in nitrogen. The thermal behaviour of components and blends was evaluated by thermogravimetry and optical microscopy of solid residues. The transformation of nitrogen functional groups on co-treatment was monitored using elemental analysis, infrared spectroscopy and X-ray photoelectron spectroscopy. Oxidized polymer behaved as an inert during co-pyrolysis. In contrast, strong interactions of unoxidized PAN with pitch could be deduced from enhanced residue yield and extensive deterioration of the optical textu…
Atomic layer deposition of Ti-Nb-O thin films onto electrospun fibers for fibrous and tubular catalyst support structures
2018
Here, the authors report on the preparation of core-shell carbon-ceramic fibrous as well as ceramic tubular catalyst supports utilizing electrospinning and atomic layer deposition (ALD). In this paper, ALD of Ti-Nb-O thin films using TiCl4, Nb(OEt)5, and H2O as precursors is demonstrated. According to the time-of-flight-elastic recoil detection analysis and Rutherford backscattering spectrometry, carbon and hydrogen impurities were relatively low, but depend on the pulsing ratio of the precursors. Optimized ALD process was used for coating of sacrificial electrospun polyvinyl alcohol (PVA) template fibers to yield tubular Ti-Nb-O structures after thermal or solution based PVA removal. Anoth…
Electrospun TiO2 embedded nanofibers for photocatalytic applications
2019
The development of photocatalysts with low cost, high reactivity and easy recovery provides great potentials for environmental remediation. In this study, polyacrylonitrile (PAN) nanofibers containing titanium dioxide ([Formula: see text]) nanoparticles were successfully fabricated using a facile electrospinning technique. The effects of [Formula: see text] content, PAN concentration and thermal treatment on the adsorption and photocatalysis properties of [Formula: see text] nanofibers have been investigated. The results indicate that the embedded [Formula: see text] nanofibers possess the property to effectively decompose rhodamine B (RhB) under simulated sunlight irradiation. The enhance…
The effect of introduction of montmorillonite clay (MMT) on the elastic properties of polycarbonate (PC) composition with acrylonitrile-butadiene sty…
2015
Abstract Polycarbonate (PC)/acrylonitrile–butadiene–styrene terpolymer (ABS)/montmorillonite (MMT) nanocomposites have been obtained by melt compounding in a twin-screw extruder. Structural and elastic properties have been characterized. The theoretical analysis of the elastic properties of PC/ABS/MMT composite with a widely varied number of elementary layers in clay filler particles has been performed in order to estimate the influence of the degree of exfoliation of particles on the effect of reinforcement of the material. Results of the theoretical analysis have been compared with the experimental data about the effects of unmodified and two types of organically modified montmorillonite …
Photoluminescence Study of Defects in ZnO-Coated Polyacrylonitrile Nanofibers
2020
International audience; Core-shell nanostructures of one-dimensional (1D) polyacrylonitrile (PAN)/zinc oxide (ZnO) were obtained by combining atomic layer deposition (ALD) and electrospinning. Nanofibers with different ZnO thicknesses were synthesized and investigated. The present work offers novel information about 1D ZnO structural defects and activation energies (Ea) by performing photoluminescence (PL) measurements. PL measurements of 1D ZnO/PAN samples were investigated from 77 K to 273 K (room temperature). By analyzing the obtained data of the emission spectrum, Ea and temperature coefficients were calculated. The results let us suggest an approximate model of defects in 1D ZnO/PAN s…
Submicron structured polymethyl methacrylate/acrylonitrile-butadiene rubber blends obtained via gamma radiation induced ?in situ? polymerization
2004
The morphology and properties of PMMA/rubber blends, obtained through gamma radiation induced “in situ” polymerization of methyl methacrylate (MMA) in the presence of small quantities of an acrylonitrile–butadiene based rubber (ABN), are presented. Different systems have been obtained by irradiating at a fixed irradiation dose rate and temperature, varying the integrated dose. All the blends obtained were characterized with respect to their melt state and solid state dynamic-mechanical response and mechanical tensile properties. In particular, the effect on the blend properties of prolonging the irradiation time was investigated. Furthermore, a morphological characterization through atomic …
Poly(styrene-b-methyl methacrylate) block copolymers as compatibilizing agents in blends of poly(styrene-co-acrylonitrile) and poly(2,6-dimethyl-1,4-…
1993
Abstract The compatibilizing effect of the symmetric narrowly distributed block copolymer poly(styrene- b -methyl methacrylate) (P(S- b -MMA)) in blends of high-molecular-weight poly(styrene- co -acrylonitrile) containing 20 wt% (PSAN20) or 43 wt% acrylonitrile (PSAN43) with poly(2,6-dimethyl-1,4-phenylene ether) (PPE) was investigated by dynamic mechanical spectroscopy and transmission electron microscopy. In blends with the PSAN43, P(S- b -MMA) forms spherical micelles in the PPE phase with no dispersing efficiency. In contrast to this, for blends with PSAN20, the block copolymer is located at the phase boundary, causing an extremely fine dispersion of the components. Depending on the loc…
Poly(styrene-b-methyl methacrylate) block copolymers as compatibilizing agents in blends of poly(styrene-co-acrylonitrile) and poly(2,6-dimethyl-1,4-…
1993
Abstract The influence of the molecular weight of the symmetric block copolymer poly(styrene-b-methyl methacrylate) (P(S-b-MMA)) in blends with high-molecular-weight poly(styrene-co-acrylonitrile) (PSAN) and poly(2,6-dimethyl-1,4-phenylene ether) (PPE) is investigated by dynamic mechanical analysis and transmission electron microscopy. Total molecular weights of the block copolymers vary from 16 up to 275 kg mol−1. Independent of molecular weight, all block copolymers locate to the interface with strong dispersing efficiency. The different block copolymers also showed approximately the same emulsifying efficiency. The degree of segmental mixing of the blocks with the respective phases is ev…
Effect of CTBN rubber inclusions on the curing kinetic of DGEBA–DGEBF epoxy resin
2003
Abstract The curing kinetics of an epoxy resin matrix, based on diglycil ether of bisphenol A and F (DGEBA–DGEBF), associated with an anhydride hardener, at different carboxyl-terminated copolymer of butadiene and acrylonitrile liquid rubber (CTBN) concentration (0–10 phr) are studied using a differential scanning calorimetry (DSC) and a stress-controlled rheometer in isothermal and dynamic conditions. The aim of this work is to correlate the presence of the rubber phase with the transition phenomena that occur during the curing process. The CTBN rubber induces a catalytic effect on the polymerization of the pure resin clearly observed by a significant enhancement of the curing rate. Calori…