Synthetic strategy of porous ZnO and CdS nanostructures doped ferroelectric liquid crystal and its optical behavior

A simple and scalable chemical approach has been proposed for the generation of 1-dimensional nanostructures of two most important inorganic materials such as zinc oxide and cadmium sulfide. By controlling the growth habit of the nanostructures with manipulated reaction conditions, the diameter and uniformity of the nanowires/nanorods were tailored. We studied extensively optical behavior and structural growth of CdS NWs and ZnO NRs doped ferroelectric liquid crystal Felix-017/100. Due to doping band gap has been changed and several blue shifts occurred in photoluminescence spectra because of nanoconfinement effect and mobility of charges

Switching of ferroelectric liquid crystal doped with cetyltrimethylammonium bromide-assisted CdS nanostructures

Large scale high yield cadmium sulfide (CdS) nanowires with uniform diameter were synthesized using a rapid and simple solvo-chemical and hydrothermal route assisted by the surfactant cetyltrimethylammonium bromide (CTAB). Unique CdS nanowires of different morphologies could be selectively produced by only varying the concentration of CTAB in the reaction system with cadmium acetate, sulfur powder and ethylenediamine. We obtained CdS nanowires with diameters of 64–65 nm and lengths of up to several micrometers. A comparative study of the optical properties of ferroelectric liquid crystal (FLC) Felix-017/100 doped with 1% of CdS nanowires was performed. Response times of the order of from 160 to 180 μs, rotational viscosities of the order of from 5000 to 3000 mN s m−2 and polarizations of the order of from 10 to 70 nC cm−2 were measured. We also observed an anti-ferroelectric to ferroelectric transition for CdS doped FLC instead of the ferroelectric to paraelectric transition for pure FLC

Unusual low temperature relaxation behavior of crosslinked acrylonitrile-butadiene co-polymer

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A critical review on the utilization of various reinforcement modifiers in filled rubber composites

Presently, the development of high-performance filled rubber composites offers a new era in the industrial field of polymer research. This article reviews the utilization of various reinforcement modifiers on the successive property enhancement of rubber composites containing different commonly used fillers like silica, nanoclay, carbon nanotube, natural fibers, and so on. The practical importance of reinforcement modifiers in rubber technology is systematically described in the light of filler dispersion, processing, and mechanical properties of filled rubber compounds. A special emphasis is given on the mechanism of interaction between reinforcement modifiers and filler surface in filled rubber composites. Filler dispersion in the rubber matrix is the key parameter that controls the ultimate performance and rubber–filler interaction of filled rubber system. The use of some fixed reinforcement modifiers is an innovative way not only to solve the dispersion problem of filler particles but also to increase the reinforcing ability of most of the fillers in filled rubber products. Thus, the concept of reinforcement modifiers has the potential to facilitate further development of filler reinforcement technology for rubber-based composite materials. </jats:p

RECLAIMING OF GROUND RUBBER TIRE BY SAFE MULTIFUNCTIONAL RUBBER ADDITIVES: I. TETRA BENZYL THIURAM DISULFIDE

ABSTRACT The present paper describes the mechanical reclaiming of ground rubber tire (GRT) by safe tetra benzyl thiuram disulfide (TBzTD), a multifunctional rubber additive. The versatility of the proposed agent is that it acts as a reclaiming agent during reclaiming and as a curing agent during revulcanization of the reclaimed materials. In this regard, we want to introduce a safe reclaiming agent in reclamation of GRT for improving its physical and mechanical performance. Reclaiming GRT has been carried out in an open roll mixing mill at various time intervals and different concentrations of the reclaiming agent (TBzTD) in the presence of spindle oil. The degree of reclaiming has been evaluated by the measurement of sol content, gel content, Mooney viscosity, inherent viscosity of sol rubber, and degree of cross-link of the reclaimed materials as a function of milling time. Also, the influence of gel content on cross-link density at various time intervals on the open two roll mixing mill has been determined. A unique correlation between gel fraction and cross-link density obtained at various time intervals and concentrations of reclaiming agent indicate that an optimization of the concentration of safe TBzTD and milling time has a positive influence on improving the efficiency of reclamation. The reclaiming conditions have been optimized in view of the mechanical properties of the revulcanized GRT and the aging resistance properties of the revulcanized reclaim. The influences of the concentration on the mechanical properties in the revulcanized reclaim have also been studied. Scanning electron microscopy (SEM) studies further indicate the coherency and homogeneity in the revulcanized reclaimed rubber when reclamation is carried out by optimum concentration of safe TBzTD after maximum time of reclaiming.</jats:p

Effect of Bis (Diisopropyl) Thiophosphoryl Disulfide on the Co-Vulcanization of Carboxylic-Acrylonitrile-Butadiene Rubber and Ethylene-Propylene-Diene Rubber Blends

Abstract The objective of the work is to prepare compatible, coherent and technologically feasible blends comprising non-polar EPDM rubber and polar carboxylic-acrylonitrile-butadiene rubber (XNBR). Using an efficient sulfur vulcanization system containing bis(diisopropyl) thiophosphoryl disulfide (DIPDIS), a coupling agent cum accelerator, EPDM-XNBR blend has been co-vulcanized. The blend vulcanizates thus produced exhibit substantially enhanced physical properties which are superior to those of either component. The compatibility of the rubber blends as judged by SEM micrographs can further be improved through a two-stage vulcanization process which promotes interphase crosslinking between the polymer phases. The interphase crosslinking was recognized from swelling experiments. The study of the blends containing carbon black reveals a profound increase in physical properties of the vulcanizates as compared to those of gum vulcanizates. The SEM micrographs of the blend vulcanizates both in one-stage and two-stage distinctly indicate the blend morphology, which accounts for the significant improvement in physical properties of EPDM-XNBR blends through in situ reactive compatibilization. A reaction scheme for the interphase crosslinking has been proposed for the co-curing of EPDM-XNBR blend.</jats:p