scholarly journals The Staining of Polymers

2002 ◽  
Vol 10 (5) ◽  
pp. 5-7
Author(s):  
Ronald W. Smith
Keyword(s):  
Electron Microscopy ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Optical Microscope ◽  
Hot Water ◽  
Polymeric System ◽  
Rubber Latex ◽  
Naturally Occurring ◽  
Contrast Mechanism ◽  
In The Beginning

In the beginning there was water-the first stain that delineated structure within a polymeric system. The polymerwas natural rubber (NR) and the system was an air-dried film of natural latex. Grenquist reported in 1929 that a dried film of natural rubber latex soaked in hot water became milky (Figure 1) and, at that stage, the latex particles could be detected by the optical microscope (OM), The contrast mechanism was provided by the absorption of water by the naturally occurring proteinaceous layers present on the congealed NR particle surfaces. There was little demand for polymer staining until the age of electron microscopy.

Staining Natural Rubber with Silver Nitrate for Electron Microscopy

1977 ◽  
Vol 50 (4) ◽  
pp. 835-841 ◽  
Author(s):  
R. W. Smith ◽  
V. L. Folt
Keyword(s):  
Electron Microscopy ◽  
World War Ii ◽  
Natural Rubber ◽  
Silver Nitrate ◽  
Raw Materials ◽  
Natural Rubber Latex ◽  
Optical Microscope ◽  
Raw Material ◽  
World War ◽  
The One

Abstract Hevea brasiliensis or natural rubber (NR) has been used for over 500 years. Until World War II, it was the basic raw material of the rubber industry. Since that time, the use of synthetic polymers has steadily increased, but the importance of NR has not diminished. In fact, the future for the natural product is very promising since it is the one polymer that is obtainable without depleting fossil fuel raw materials. Natural rubber latex has been extensively studied by a variety of methods, especially the microscope. All of the early work with NR latex was conducted, of course, with the optical microscope. In the late 1940's the electron microscope began to be used, but at that time synthetic rubbers began to demand attention, and work on NR latex diminished. Perhaps investigators felt they knew all there was to know about the microscopical characteristics of this material. Indeed, some very fine work had been done and keen observations made with optical microscopes that could not even resolve all of the particles in a latex material. This paper deals with the electron microscopy of natural rubber latexes with particular attention to the proteinaceous layer on the particle and the fate of particles during varying stages of mastication. The critical technique used was to stain the proteinaceous layer of the latex particle with silver nitrate.

Effect of Leaching Treatment on Mechanical Properties of Natural Rubber Latex (NRL) Products Filled Modified Kaolin

2014 ◽  
Vol 548-549 ◽  
pp. 90-95 ◽  
Author(s):  
Hamidah Harahap ◽  
Elmer Surya ◽  
Indra Surya ◽  
Hanafi Ismail ◽  
Baharin Azahari
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Infra Red ◽  
Scanning Electron

In this study, an effect of leaching treatment on the mechanical properties of natural rubber latex (NRL) products was investigated. The products were prepared by compounding the NRL dispersion system with modified kaolin as fillers then it was formed by dipping method. It was found that incorporation of fillers in NRL would result in lowering mechanical properties of vulcanizates when the leaching was performed. The results were confirmed further by characterization of Fourier-Transform Infra-Red (FTIR) and Scanning Electron Microscopy (SEM).

Development of Natural Rubber Latex Foam for Hand Exercising Application

2020 ◽  
Vol 861 ◽  
pp. 154-158
Author(s):  
Surasit Kajon ◽  
Voranuch Somsongkul ◽  
Pimsiree Suwanna
Keyword(s):  
Electron Microscopy ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Raw Material ◽  
Accelerated Ageing ◽  
Hardness Index ◽  
Rubber Latex ◽  
Compression Set ◽  
Allergenic Potential ◽  
Scanning Electron

This study has developed an alternative compounding formulation and process for natural rubber latex (NRL) foams for hand exercising application. Deprotenized natural rubber latex was used as raw material and a combination of DIXP and TBzTD, which were fugitive and high molecular weight accelerators, respectively, was used to lower allergenic potential and harmful nitrosamines. The NRL foams were prepared to various densities, characterized by Scanning Electron Microscopy (SEM) and tested for hardness index, accelerated ageing and compression set in comparison to the foams with conventional compounding formulation. With the same processes, the foams with these two different formulations were found to have similar densities and hardness indices. However, the foams using DIXP and TBzTD accelerators performed better in compression set and accelerated ageing tests.

The Modification of Asphalt Emulsion Using Pre-Vulcanized Natural Rubber Latex for Highway Application

2010 ◽  
Vol 93-94 ◽  
pp. 639-642 ◽  
Author(s):  
Saovaros Malithong ◽  
Chanchai Thongpin
Keyword(s):  
Natural Rubber ◽  
Softening Point ◽  
Fire Hazard ◽  
Natural Rubber Latex ◽  
Optical Microscope ◽  
Asphalt Emulsion ◽  
Rubber Latex ◽  
Modified Asphalt ◽  
Swell Ratio ◽  
Asphalt Emulsions

Asphalt emulsion is manufactured by emulsification of asphalt, and it is an energy-saving, ecologically safe material because it does not need any heating processes which can emit gas and fire hazard in its use. The purpose of this study is to elucidate the feasibility on using pre-vulcanized natural rubber latex as an admixture for asphalt emulsion in order to improve thermal stability and useful mechanical properties of the asphalt emulsion. The crosslink density was determined by swell ratio. The effect of vulcanizing agent on residue properties of modified asphalt emulsions was studied. The morphology properties of the modified asphalt were also investigated by using an optical microscope. The results showed that asphalt emulsion which was modified using pre-vulcanized NR latex could provide a standard asphalt emulsion and applicable for highway construction application. The mechanical and physical properties of the dried asphalt emulsion were also very well modified by the vulcanized rubber phase. The residue properties of modified asphalt with natural rubber and pre-vulcanized natural rubber latex, including softening point and penetration was improved. The increase in vulcanizing agent could also increase softening point. At low polymer contents, the samples reveal the existence of dispersed polymer particles in a continuous bitumen phase, whereas at high polymer contents a continuous polymer phase was observed.

The Microstructure of Natural Rubber Latex Films

1997 ◽  
Vol 70 (4) ◽  
pp. 549-559 ◽  
Author(s):  
S. Cook ◽  
P. E. F. Cudby ◽  
R. T. Davies ◽  
M. D. Morris
Keyword(s):  
Electron Microscopy ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Osmium Tetroxide ◽  
Natural Rubber Latex ◽  
Mesh Size ◽  
Latex Film ◽  
Rubber Latex ◽  
Microscopy Technique ◽  
Transmission Electron

Abstract An electron microscopy technique which has been used to visualize the crosslinked regions in vulcanized blends of dry rubber has now been applied to films made from natural rubber (NR) latex. The method involves swelling the latex film with styrene, polymerizing the styrene, sectioning the sample and then staining with osmium tetroxide to reveal the rubber network when observed by transmission electron microscopy (TEM). The micrographs show the higher ratio of interparticle to intraparticle crosslinks in a sulphur post-vulcanized film as compared with a sulphur prevulcanized film. They also show that, as in dry rubber films, the mesh size of the visible rubber network correlates with the crosslink density of the rubber. The technique also reveals that the crosslink distribution in peroxide prevulcanized latex (PPVL) is significantly different from that in latices prevulcanized using sulphur or radiation.

Zinc Oxide Testing of Latex

1955 ◽  
Vol 28 (4) ◽  
pp. 1211-1220 ◽  
Author(s):  
E. W. Madge ◽  
H. M. Collier ◽  
J. L. M. Newnham
Keyword(s):  
Zinc Oxide ◽  
Natural Rubber ◽  
Mechanical Stability ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Experimental Conditions ◽  
Ammonia Content ◽  
Similar Investigation ◽  
Naturally Occurring ◽  
Viscosity Changes

Abstract Viscosity changes in concentrated natural rubber latex under different experimental conditions were investigated with the object of determining the mechanism of zinc oxide thickening and to find reasons for inconsistencies in correlating results of the zinc oxide thickening or ZOT test with other latex tests. It has been found that small variations of the amount of naturally occurring soap are of great importance in the thickening of latex containing zinc oxide, especially at the low ammonia content used for the ZOT test. The effect of added soap on the ZOT test was found to vary from latex to latex and to be different for different soaps. Less than about 0.3 per cent of various soaps added to latex prior to the zinc oxide reduced the degree and rate of thickening. With more than this amount of soap, the thickening depended on the soap used. A similar investigation in which the mechanical stability of latexes containing varying amounts of added soap and a standard amount of zinc oxide was measured, showed that the latexes varied anomalously with the amount and the type of soap added. The results of the work presented in this paper show that new tests for the zinc sensitivity of latexes must take into account a number of hitherto unsuspected factors, particularly when such tests are required to have a bearing on processing behavior.

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