Reinforcement of Latex Rubber by the Incorporation of Amphiphilic Particles

Abstract As high elasticity is a property possessed only by substances of high molecular weight, it is of interest to enquire into the relation between the elastic properties of a highly elastic material such as rubber and its molecular weight. An investigation on these lines has been made possible through the work of Bloomfield and Farmer, who have succeeded in separating natural rubber into fractions having different average molecular weights. The more important physical properties of these fractions have been examined with the object of determining which of the properties are dependent on molecular weight and which are not. Fairly extensive observations were made on the fractions from latex rubber referred to as Nos. 2, 3 and 4 by Bloomfield and Farmer, and some less extensive observations were carried out on the less oxygenated portion of fraction No. 1 obtained from crepe rubber (called hereafter 1b) . Before considering these experimental results, and their relation to the molecular weights of the fractions, it will be necessary to refer briefly to the methods used for the molecular-weight determinations, and to discuss the significance of the figures obtained.

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Plant population, planting date, and germplasm effects on guayule latex, rubber, and resin yields

Industrial Crops and Products ◽

10.1016/j.indcrop.2008.05.010 ◽

2009 ◽

Vol 29 (1) ◽

pp. 255-260 ◽

Cited By ~ 16

Author(s):

T.A. Coffelt ◽

F.S. Nakayama ◽

D.T. Ray ◽

K. Cornish ◽

C.M. McMahan ◽

...

Keyword(s):

Planting Date ◽

Plant Population ◽

Latex Rubber

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Improved chamber for the isolation of anaerobic microorganisms

Journal of Clinical Microbiology ◽

10.1128/jcm.4.1.40-45.1976 ◽

1976 ◽

Vol 4 (1) ◽

pp. 40-45

Author(s):

M E Cox ◽

J I Mangels

Keyword(s):

Anaerobic Bacteria ◽

Gas Mixture ◽

Anaerobic Conditions ◽

Co2 Gas ◽

Anaerobic Microorganisms ◽

The Media ◽

To Receive ◽

Latex Rubber

A small portable chamber for the recovery of anaerobic bacteria is described. This rigid chamber is constructed of clear acrylic with dimensions of 30 inches (ca. 76.2 cm) wide, 18 inches (ca. 44.7 cm) deep, and 18 inches (ca. 44.7 cm) high. Conventional bacteriological techniques can be used inside the chamber to efficiently isolate strict anaerobic organisms. An adapter allows the attachment of a standard anaerobic jar to the outside of the chamber. The jar can be used to store reduced media. Once the jar is attached to the chamber and the media is removed to the interior of the chamber, the jar is available to receive inoculated media. The anaerobic jar can then be removed from the chamber, without contaminating the jar or chamber with oxygen, and be placed in a conventional 37degreesC incubator. This chamber also allows the microbiologist to process cultures without wearing gloves as was necessary with previous anaerobic chambers. Air-tight latex rubber sleeves seal around the microbiologists arms and to the armport flange of the chamber to prevent the introduction of oxygen into the chamber. Anaerobic conditions are maintained by circulating a 80% N2, 10% H2, 10% CO2 gas mixture through alumina pellets coated with palladium. This study indicates that anaerobic conditions obtained in this chamber are sufficient for recovery of obligate anaerobes.

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Experimental Study on the Mechanical Properties of the Crumb Rubber Concrete Modified by Latex

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.941-944.739 ◽

2014 ◽

Vol 941-944 ◽

pp. 739-742

Author(s):

Wei Li ◽

Zhen Huang ◽

Xiao Chu Wang ◽

Jian Peng Zhang

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Crumb Rubber ◽

Test Results ◽

Rubber Latex ◽

Rubber Surface ◽

Adhesive Ability ◽

Styrene Butadiene ◽

Rubber Concrete ◽

Latex Rubber

Through modification of the rubber surface, the adhesive ability of rubber particles and cement based materials has increased, thus improving the mechanical properties of rubber concrete. Dosage of styrene butadiene latex was studied under the condition of 5% cement quality, the change regularity of different amount of rubber latex rubber modified concrete compressive, splitting, flexural strength and other mechanical properties. The test results prove that the latex rubber mixing can improve compressive, splitting and flexural strength of concrete.

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Properties of Ebonite. XXX. Influence on Properties of Ebonite of the Type of Raw Rubber Used, with Special Reference to Purified Rubbers

Rubber Chemistry and Technology ◽

10.5254/1.3542941 ◽

1949 ◽

Vol 22 (1) ◽

pp. 232-244

Author(s):

D. G. Fisher ◽

J. R. Scott ◽

W. H. Willott

Keyword(s):

Dielectric Properties ◽

Electrical Properties ◽

Dielectric Loss ◽

Natural Rubber ◽

Power Factor ◽

Breakdown Strength ◽

Practical Importance ◽

Water Soluble ◽

Plastic Yield ◽

Latex Rubber

Abstract Tests have been made on unloaded ebonites prepared from ordinary commercial types of natural rubber, special (deproteinized) rubbers having reduced contents of protein and(or) other water-absorbent substances, and a whole-latex rubber containing relatively large percentages of these substances, to determine to what extent these substances influence the electrical properties of the ebonite and, hence, whether any technically useful improvement can be effected by using specially prepared rubbers. Permittivity and power factor at 106 cycles per second, but particularly power factor, are somewhat improved by using the special rubbers, so that the dielectric loss can be reduced by about 30 per cent. In addition, the increase in dielectric loss caused by exposure to high humidity or by a rise of temperature is in general lessened by the use of these rubbers. Similar, though smaller, improvements in the properties of the ebonite are obtained by washing ordinary commercial rubber (smoked sheet). Although a definite improvement in dielectric loss is obtained, it does not seem probable that purification of natural rubber would lead to ebonites with dielectric properties approaching those of polystyrene, for instance. It seems unlikely that even complete elimination of the water-absorbent impurities would reduce the dielectric loss by more than 50 per cent; the rubber-sulfur compound itself thus appears to be responsible for a fair proportion of the loss normally observed. The large percentages of water-soluble substances present in whole-latex rubber increase the permittivity and especially the power factor of the ebonite made from it. The dielectric properties of ebonite are related, though not closely, to its water-absorbing capacity and that of the raw rubber used, low absorption being in general accompanied by low dielectric loss and reduced sensitiveness to humidity variations. There is only a rough parallelism between the water absorptions of raw rubbers and the corresponding ebonites. Probable reasons for this are indicated. It is concluded that water absorption tests on raw rubber form a useful, though only approximate, guide to its value for making electrical ebonite; electrical tests on the ebonite must be the final criterion. Apart from very impure whole-latex rubber, no correlation can be traced between the inorganic content (ash) of ebonite and its electrical properties. The probable reason for this is indicated. There is evidence that the dielectric loss of ebonite may increase with the passage of time. In view of its obvious theoretical and practical importance, this phenomenon requires further study. No technically useful advantage as regards breakdown strength, volume resistivity, surface resistivity, or stability to light, by the use of the special rubbers, is evident in the present work. The plastic yield characteristics of ebonite are not appreciably altered by using special rubbers. Estimations of uncombined sulfur and also plastic yield tests show that one of the deproteinized rubbers vulcanizes more rapidly than the rest, which differ little among themselves.

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