Abstract: | 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. |
URI: | http://dyuthi.cusat.ac.in/purl/855 |
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Laliamma Jose a ... s on latex..,April1997.PDF | (4.118Mb) |
Abstract: | Paraphenylenediamine and diphenylamine were chemically attached to natural rubber during mastication . The rubber bound antioxidants were characterized by TLC, 'H-NMR, IR and TGA. The efficiency and permenance of these bound antioxidants were compared with a conventional amine type antioxidant in filled natural rubber vulcanizates . The rubber bound antioxidants were found to be less volatile and less extractable as compared to conventional antioxidants. The vulcanizates showed improved ageing resistance as compared to vulcanizates containing conventional antioxidants. This semisolid rubber bound antioxidant can reduce the amount of plasticizer required for compounding. |
URI: | http://dyuthi.cusat.ac.in/purl/846 |
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Shanti A Avirah ... on mastication...,1995.PDF | (10.04Mb) |
Abstract: | Diphenylamine was chemically attached to depolymerised natural rubber by photochemical reaction. The rubber-bound diphenylamine was characterised by TLC, HNMR, IR and TGA. The efficiency and permanence of the bound diphenylamine was compared with conventional amine type antioxidant in natural rubber vulcanizates. The rubber-bound diphenylamine was found to be less volatile and less extractable compared to the conventional antioxidant. The vulcanizates showed improved ageing resistance in comparison to vulcanizates containing conventional antioxidant . Also, the presence of liquid rubber-bound diphenylamine reduces the amount of plasticiser required for compounding. |
URI: | http://dyuthi.cusat.ac.in/purl/847 |
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Shanti A Avirah ... ies on natural...,1994.PDF | (4.471Mb) |
Abstract: | Para-phenylenediamine (PD) was chemically attached to depolymerized natural rubber by a photochemical reaction . The rubber bound PD was characterized by TLC, 1H-NMR, IR, and TGA. The efficiency and permanence of the bound PD were compared with conventional antioxidants in NBR vulcanizates . The rubber bound PD was found to be less volatile and more resistant to water and oil extraction . The vulcanizates showed improved aging resistance in comparison to vulcanizates containing conventional antioxidants. The liquid rubber bound antioxidant reduces the amount of plasticizer required for compounding |
URI: | http://dyuthi.cusat.ac.in/purl/849 |
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Shanti A Avirah ... seph,Studies on..,1995.PDF | (7.669Mb) |
Abstract: | Studies conducted on butadiene-acrylonitrile copolymer (NBR)/poly(vinyl chloride) (PVC) blends at different temperatures indicate that an optimum temperature exists for the formation of a particular blend. The mechanical properties of the blends confirm this observation. PVC stabilizer based on, magnesium oxide , zinc oxide, and stearic acid was found to be very useful in NBR/PVC blends. |
URI: | http://dyuthi.cusat.ac.in/purl/824 |
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K E George and others Studies on NBR, 1986.PDF | (4.299Mb) |
Abstract: | Antioxidants were attached to hydroxy-terminated liquid natural rubber by modified Friedel-Crafts alkylation reaction using anhydrous zinc chloride as catalyst. The rubber bound antioxidants were found to be less volatile and less extractable compared to conventional antioxidants. The bound antioxidants were tried both in latex compounds and dry rubber compounds. The vulcanizates showed improved ageing resistance compared to vulcanizates based on conventional antioxidants. |
URI: | http://dyuthi.cusat.ac.in/purl/848 |
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Shanti A Avirah ... on rubber...,June1991.PDF | (5.434Mb) |
Abstract: | ABSTRACT: Nylon tire cord (1680/2) was dipped in different adhesives based on resorcinol formaldehyde resin and latex (RFL) and was bonded to natural rubber-based compounds. The resin-rubber ratio in the RFL adhesive was optimized. The variation of pull-through load was studied by varying the drying and curing temperature of the dipped nylon tire cord. RFL adhesive based on vinylpyridine latex was found to have better rubber-to-nylon tire cord bonding, compared with the one based on natural rubber latex. Addition of a formaldehyde donor into the RFL adhesive/rubber compound improves adhesion. |
URI: | http://dyuthi.cusat.ac.in/purl/856 |
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Lynta Job and R ... Studies on...,July1998.PDF | (4.180Mb) |
Abstract: | In natural rubber/high styrene resin microcellular sheets, part of natural rubber was replaced by latex reclaim prepared from waste latex products. The mechanical properties and cell structure of the products were evaluated. It was found that latex reclaim can replace about 30% of natural rubber without affecting the technical properties of the microcellular sheets. |
URI: | http://dyuthi.cusat.ac.in/purl/844 |
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Reena Susan George and Rani Joseph,1996.PDF | (4.186Mb) |
Abstract: | 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. |
URI: | http://dyuthi.cusat.ac.in/purl/839 |
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Rani Joseph and others,Studies on..Nov1986.PDF | (5.981Mb) |
Abstract: | 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. |
URI: | http://dyuthi.cusat.ac.in/purl/837 |
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Rani Joseph and others,Studies on...,1988.PDF | (7.445Mb) |
Abstract: | Blends of natural rubber (NR) with styrene-butadiene rubber (SBR), polybutadiene rubber (BR), ethylene-propylene terpolymer (EPDM) and acrylonitrile-butadiene rubber (NBR) were vulcanised using an efficient vulcanisation (EV) system and a semi-EV system. Compatible blends show a definite pattern of curing whereas the incompatible blends show no such pattern. |
URI: | http://dyuthi.cusat.ac.in/purl/836 |
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Rani Joseph an ... s on the cure..1985PDF.PDF | (2.440Mb) |
Abstract: | Polypyrrole/poly (vinyl chloride) semi-interpenenzrtirtg networks of different compositions are prepared using anunonitun per sulfate initiator at room temperature in pellet.form and lilrrt form and their dielectric properties are studied at different microwave frequencies. An HP 8510 Vector network analyzer interfaced with a computer is used. The cavity-perturbation technique is employed for the study |
URI: | http://dyuthi.cusat.ac.in/purl/802 |
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Honey John and ... dielectric...,Dec2005.PDF | (2.487Mb) |
Abstract: | Poly(o-toluidine) (PoT) and poly(o-toluidine co aniline) were prepared by using ammonium persulfate initiator, in the presence of 1M HCI. It was dried under different conditions: room temperature drying (48 h), oven drying (at 50°C for 12 h), or vacuum drying (under vacuum, at room temperature for 16 h). The dielectric properties, such as dielectric loss, conductivity, dielectric constant, dielectric heating coefficient, loss tangent, etc., were studied at microwave frequencies. A cavity perturbation technique was used for the study. The dielectric properties were found to be related to the frequency and drying conditions. Also, the copolymer showed better properties compared to PoT alone. |
URI: | http://dyuthi.cusat.ac.in/purl/801 |
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Honey John and others,oct.2003.PDF | (4.775Mb) |
Abstract: | ABSTRACT: The dipping characteristics of radiation-vulcanized natural rubber latex and natural rubber latex compounds were investigated with a lab-model semiautomatic dipping machine. The effect of the variation of the speed of immersion and withdrawal, dwell time, compound viscosity, and concentration of coagulant on the thickness of the latex deposit was investigated. The results of the study show that the deposit thickness depends on the withdrawal speed of the former, the concentration of the coagulant, dwell times, and the viscosity of the latex compounds |
URI: | http://dyuthi.cusat.ac.in/purl/854 |
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K K Sasidharan ... the dipping...,Nov2000.PDF | (5.660Mb) |
Abstract: | Latex waste products contain rubber hydrocarbon of very high quality, which is only lightly cross linked. Selected wastes such as thread waste and glove waste were modified into processable materials by a novel economic process and thermoplastic elastomers were prepared by blending these modified waste materials with high density polyethylene in various proportions. The mechanical properties as well as the rheological behaviour of these blends were evaluated and compared with those of the natural rubber-high density polyethylene blends. |
URI: | http://dyuthi.cusat.ac.in/purl/869 |
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S Rajalekshmi a ... chanical.........,2002.PDF | (5.540Mb) |
Abstract: | Latex waste like glove waste was effectively modified using a new reclaiming agent, thiocarbanilide. This modified waste was blended with linear low-density polyethylene (LLDPE) to develop a novel thermoplastic elastomer. Both uncrosslinked and dynamically crosslinked blends were prepared and their properties were studied. The results were found to be comparable to those of conventional thermoplastic elastomers. |
URI: | http://dyuthi.cusat.ac.in/purl/810 |
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S Rajalekshmi and Rani Joseph,studies on...PDF | (7.257Mb) |
Abstract: | Zinc butyl xanthate [Zn(bxt)2] was prepared in the laboratory . The effect of this xanthate with zinc diethyl dithiocarbamate (ZDC) on the vulcanization of natural rubber ( NR), polybutadiene rubber (BR), and NR/BR blend has been studied at different temperatures. The amounts of Zn (bxt)2 and ZDC in the compounds were optimized by varying the amount of ZDC from 0 . 75 to 1.5 phr and Zn (bxt)2 from 0 . 75 to 1 .5 phr. The cure characteristics were also studied . HAF filled NR, BR, and NR / BR blend compounds were cured at different temperatures from 60 to 150 C. The sheets were molded and properties such as tensile strength, tear strength, crosslink density and elongation at break, compression set, abrasion resistance, etc. were evaluated. The results show that the mechanical properties of 80NR/20BR blends are closer to that of NR vulcanizates, properties of 60NR/40BR blends are closer to BR vulcanizates, while the 70NR/30BR blends show an intermediate property. |
URI: | http://dyuthi.cusat.ac.in/purl/813 |
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Shiny Palaty an ... ,Studies on..march2006.PDF | (3.705Mb) |
Abstract: | The mechanical properties of filled natural rubber latex vulcanizates were found to be improved by the addition of polyethylene glycols of different molecular weight and glycerol. There is a slight reduction in the optimum cure times of the compounds containing PEG/Glycerol. The morphology study shows that the filler distribution is more uniform in the compounds containing PEG/Glycerol. |
URI: | http://dyuthi.cusat.ac.in/purl/828 |
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Laliamma Jose ... ph,Study of the..,1994.PDF | (9.145Mb) |
Abstract: | Natural rubber/isora fibre composites were cured at various temperatures. The solvent swelling characteristics of natural rubber composites containing both untreated and alkali treated fibres were investigated in aromatic and aliphatic solvents like toluene, and n-hexane. The diffusion experiments were conducted by the sorption gravimetric method. The restrictions on elastomer swelling exerted by isora fibre as well as the anisotropy of swelling of the composite have been confirmed by this study. Composite cured at 100°C shows the lowest percentage swelling. The uptake of aromatic solvent is higher than that of aliphatic solvent for the composites cured at all temperatures. The effect of fibre loading on the swelling behaviour of the composite was also investigated in oils like petrol, diesel, lubricating oil etc. The % swelling index and swelling coefficient of the composite were found to decrease with increase in fibre loading. This is due to the increased hindrance exerted by the fibres at higher fibre loadings and also due to the good fibre-rubber interactions. Maximum uptake of solvent was observed with petrol followed by diesel and then lubricating oil. The presence of bonding agent in the composites restrict the swelling considerably due to the strong interfacial adhesion. At a fixed fibre loading, the alkali treated fibre composite showed lower percentage swelling compared to the untreated one. |
URI: | http://dyuthi.cusat.ac.in/purl/807 |
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Lovely Mathew a ... g behavior..,Sept.2005.PDF | (6.644Mb) |
Abstract: | Zinc salts of ethyl, isopropyl and butyl xanthates were prepared in the laboratory. The effect of these xanthates with zinc diethyldithiocarbamate (ZDC) on the vulcanization of HAF filled NR compound has been studied at different temperatures. The rubber compounds with the three xanthate accelerators and ZDC were cured at various temperatures from 60°C to 150°C. The sheets were moulded and properties such as tensile strength , tear strength , cross-link density, elongation -at-break, compression set, heat build up, abrasion resistance, flex resistance , etc. were evaluated . The properties showed that zinc xanthate/ZDC accelerator combination has a positive synergistic effect on the mechanical properties of NR compounds. The curing of HAF filled NR compound containing zinc xanthate /ZDC is slightly slower than the curing of the corresponding gum compounds . It is observed that, by gradually increasing the amount of the accelerator, the cure time of black filled NR compound can be made equal to that of the gum compou |
URI: | http://dyuthi.cusat.ac.in/purl/814 |
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Shiny Palaty an ... nergism of...,July2003.PDF | (5.107Mb) |
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