Fabrication and Characterization of Methylene-Blue-Doped Polyvinyl Alcohol–Polyacrylicacid Blend for Holographic Recording

A methylene-blue-sensitized polymer blend of polyvinyl alcohol and polyacrylic acid is fabricated and tested for holographic recording. It was found to have good characteristics such as high sensitivity, storage stability, ease of fabrication, and environmental stability. Optimization of the ratio of polyvinyl alcohol polyacrylic acid, the sensitizer concentration, pH, energy, diffraction efficiency measurements, etc., have been done. pH is found to have a great influence on the recovery of the dye in this matrix. The results of experimental investigations into the properties of this new material are reported.

Fabrication and Characterization of Methylene-Blue-Doped Polyvinyl Alcohol–Polyacrylic Acid Blend for Holographic Recording

A methylene-blue-sensitized polymer blend of polyvinyl alcohol and polyacrylic acid is fabricated and tested for holographic recording. It was found to have good characteristics such as high sensitivity, storage stability, ease of fabrication, and environmental stability. Optimization of the ratio of polyvinyl alcohol polyacrylic acid, the sensitizer concentration, pH, energy, diffraction efficiency measurements, etc., have been done. pH is found to have a great influence on the recovery of the dye in this matrix. The results of experimental investigations into the properties of this new material are reported.

Modification of Butadiene -Acrylonitrile Rubber/ Poly(Vinyl Chloride) Blend Using Natural Rubber, Styrene-Butadiene Rubber, and Polybutadiene Rubber

Natural rubber, styrene-butadiene rubber, and polybutadiene rubber were used to replace part of the butadieneacrylonitrile rubber in a 70/30 butadiene-acrylonitrile rubber/ poly(vinyl chloride) blend. Such replacement up to 15% of the total weight of the blend improved the mechanical properties, while decreasing the cost of the blend. Styrenebutadiene rubber could replace butadiene-acrylonitrile rubber up to 30% of the total weight of the blend without deterioration in the mechanical properties.

Studies on the Cure Characteristics and Vulcanizate Properties of 50 / 50 NR /SBR Blend

Blends of 50/50 natural rubber (NR) and styrene-butadiene rubber (SBR) are vulcanized using several conventional and semi-EV systems. The cure characteristics and vulcanizate properties are compared. The quantity and quality of crosslinks in each case are deciphered by chemical probes to correlate them with the vulcanizate properties.

Studies on 50/50 Natural Rubber/Styrene Butadiene Copolymer Blend

A carbon black filled 50/50 natural rubber (NR)/styrene-butadiene rubber (SBR) blend is vulcanized using several conventional curing systems designed by varying the amounts of sulphur and accelerator. The cure characteristics and the properties of the vulcanizates are compared. The quantity and quality of crosslinks in each case are evaluated by chemical probes to correlate them with the properties.

Studies on the Cure Characteristics and Vulcanizate Properties of 50/50 NR/BR Blend

A carbon black filled 50/50 Natural Rubber (NR)/Polybutadiene Rubber (BR) blend is vulcanized using several conventional systems designed by varying the amounts of sulphur and accelerator . The cure characteristics and the vulcanizate properties are compared. The quality and quantity of crosslinks in each case are deciphered by chemical probes to correlate them with the vulcanizate properties.

Studies on Latex Stage Carbon Black Masterbatching of NR and its Blend with SBR

Carbon Black is incorporated In natural rubber latex in , the presence of polyethylene glycol. The dispersion of carbon blade in the vulcanizatea is analyzed using polaroid M.4 land camera The mechanical properties of the carbon black meeterbatched NR/SBR blend Is compared with that of conventional NR/SBR blend before and after ageing , The resilience, flex resistance and hardness are found to be superior for N-LCMISBR compounds. The compression set and abrasion resistance are comparable for both types of blends . The processebiity and die swell of these blends at different shear rates are also compared.

Development of Polybutadiene (BR)-Polyethylene (LDPE) Blend Based Microcellular Soles for Low-Temperature Applications

Microcellular (MC) soles based on polybutadiene (BR) and low-density polyethylene (LDPE) blends for low-temperature applications were developed. A part of BR in BR-LDPE blend was replaced by natural rubber (NR) for property improvement. The BR-NR-LDPE blend-based MC sole shows good technical properties. Sulphur curing and DCP curing were tried in BR-LDPE and NR-BR-LDPE blends. Study shows that sulphur-cured MC sheets possess better technical properties than DCPcured MC sheets. 90/10 BR-LDPE and 60/30/10 BR-NR-LDPE blend combinations are found to be suitable for low-temperature applications.

Effect of Silane Coupling Agent on Cure Characteristics and Mechanical Properties of Nitrile Rubber/Reclaimed Rubber Blend

Blends of nitrile rubber and reclaimed rubber containing different levels of a coupling agent, Si 69 (bis(3- triethoxysilyl propyl)(tetrasulphide) were prepared and the cure characteristic's and mechanical properties were studied. Optimum loading of Si-69 was found to be a function of blend ratio. 3 phi- of Si 69 in a 70:30. Blend was found to be the optimum combination with respect to the mechanical properties. The rate and state of cure were also affected bv the conp/ing agent. Tensile strength, tear strength and abrasion resistance were improved in the presence of coupling agent. While the state of cure improved, the cure rate and scorch time decreased with increasing silane content. Ageing studies showed that the blends containing the coupling agent were inferior to the unmodified blends.

Effect of Silane Coupling Agent on Cure Characteristics and Mechanical Properties of Chloroprene Rubber/Reclaimed Rubber Blend

Chloroprene rubber was blended with whole tire reclaimed rubber (WTR) in presence of different levels of a coupling agent Si69 [bis- (3-(triethoxysilyl)propy1)tetrasuIfide] and the cure characteristics and mechanical properties were studied. The rate and state of cure were also affected by the coupling agent. While the cure time was increased, the cure rate and scorch time were decreased with increasing silane content. Tensile strength, tear strength, and abrasion resistance were improved in the presence of coupling agent. Compression set and resilience were adversely affected in presence of silane-coupling agent.Aging studies showed that the blends containing the coupling agent were inferior to the unmodified blends.

Modification of Polypropylene/High Density Polyethylene Blend Using Nanokaolinite Clay and E-Glass Fibre: Preparation, Characterization and Micromechanical Modelling

Upgrading two widely used standard plastics, polypropylene (PP) and high density polyethylene (HDPE), and generating a variety of useful engineering materials based on these blends have been the main objective of this study. Upgradation was effected by using nanomodifiers and/or fibrous modifiers. PP and HDPE were selected for modification due to their attractive inherent properties and wide spectrum of use. Blending is the engineered method of producing new materials with tailor made properties. It has the advantages of both the materials. PP has high tensile and flexural strength and the HDPE acts as an impact modifier in the resultant blend. Hence an optimized blend of PP and HDPE was selected as the matrix material for upgradation. Nanokaolinite clay and E-glass fibre were chosen for modifying PP/HDPE blend. As the first stage of the work, the mechanical, thermal, morphological, rheological, dynamic mechanical and crystallization characteristics of the polymer nanocomposites prepared with PP/HDPE blend and different surface modified nanokaolinite clay were analyzed. As the second stage of the work, the effect of simultaneous inclusion of nanokaolinite clay (both N100A and N100) and short glass fibres are investigated. The presence of nanofiller has increased the properties of hybrid composites to a greater extent than micro composites. As the last stage, micromechanical modeling of both nano and hybrid A composite is carried out to analyze the behavior of the composite under load bearing conditions. These theoretical analyses indicate that the polymer-nanoclay interfacial characteristics partially converge to a state of perfect interfacial bonding (Takayanagi model) with an iso-stress (Reuss IROM) response. In the case of hybrid composites the experimental data follows the trend of Halpin-Tsai model. This implies that matrix and filler experience varying amount of strain and interfacial adhesion between filler and matrix and also between the two fillers which play a vital role in determining the modulus of the hybrid composites.A significant observation from this study is that the requirement of higher fibre loading for efficient reinforcement of polymers can be substantially reduced by the presence of nanofiller together with much lower fibre content in the composite. Hybrid composites with both nanokaolinite clay and micron sized E-glass fibre as reinforcements in PP/HDPE matrix will generate a novel class of high performance, cost effective engineering material.

Modification of Polypropylene/Polystyrene blend using Nanoclay and Sisal Cellulose nano fiber

Cochin University of Science and Technology

Methylene Blue Doped Polymers: efficient Media for Optical Recording

Polymer materials find application in optical storage technology, namely in the development of high information density and fast access type memories. A new polymer blend of methylene blue sensitized polyvinyl alcohol (PVA) and polyacrylic acid (PAA) in methanol is prepared and characterized and its comparison with methylene blue sensitized PVA in methanol and complexed methylene blue sensitized polyvinyl chloride (CMBPVC) is presented. The optical absorption spectra of the thin films of these polymers showed a strong and broad absorption region at 670-650 nm, matching the wavelength of the laser used. A very slow recovery of the dye on irradiation was observed when a 7:3 blend of polyvinyl alcohol/polyacrylic acid at a pHof 3.8 and a sensitizer concentration of 4.67 10 5 g/ml were used. A diffraction efficiency of up to 20% was observed for the MBPVA/alcohol system and an energetic sensitivity of 2000 mJ/cm2 was obtained in the photosensitive films with a spatial frequency of 588 lines/mm.