The Natural Higher Fatty Acid Soaps in Natural Rubber Latex and Their Effect on the Mechanical Stability of the Latex

1984 ◽  
Vol 57 (2) ◽  
pp. 243-253 ◽  
Author(s):  
Seong-Fong Chen ◽  
Chiew-Sum Ng
Keyword(s):  
Fatty Acid ◽  
Extraction Method ◽  
Surface Charge Density ◽  
Mechanical Stability ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Latex Particles ◽  
Rate Of Increase ◽  
Hydrolysis Of ◽  
Better Than

Abstract The natural HFA soaps present in ammoniated NR latex concentrates are derived from the hydrolysis of the saponifiable lipids on the surfaces of the latex particles. A method based on cold extraction of the soaps has been developed for determining the natural HFA soaps in freshly concentrated latices. This method is better than the hot extraction method, which has been shown to cause some hydrolysis of the lipids. The natural HFA soaps in NR latex increase with time and reach a constant value in 3 to 6 weeks. The rate of increase of the soaps is divided into two linear regions and is more rapid in the first 1 to 2 weeks. More than 92% of the natural HFA soaps are adsorbed on the surfaces of the latex particles. This results in an increase in the negative electrical surface charge density of the particles and causes an increase in the mechanical stability of the latex. In fact, the increase in log MST is linearly proportional to the increase in natural HFA soaps in the latex. After the natural HFA soaps become constant, further increase in MST value is likely to be caused partly by the oxygen from the air.

Surface nanostructure of Hevea brasiliensis natural rubber latex particles

2011 ◽  
Vol 390 (1-3) ◽  
pp. 157-166 ◽  
Author(s):  
Kanjanee Nawamawat ◽  
Jitladda T. Sakdapipanich ◽  
Chee C. Ho ◽  
Yujie Ma ◽  
Jing Song ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Hevea Brasiliensis ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Latex Particles ◽  
Surface Nanostructure

Pre‐Vulcanization of Large and Small Natural Rubber Latex Particles: Film‐Forming Behavior and Mechanical Properties

2019 ◽  
Vol 304 (9) ◽  
pp. 1900283
Author(s):  
Manus Sriring ◽  
Adun Nimpaiboon ◽  
Nattanee Dechnarong ◽  
Sirirat Kumarn ◽  
Yuji Higaki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Latex Particles ◽  
Film Forming

Grafting characterization of natural rubber latex particles: wet-STEM imaging contributions

2008 ◽  
Vol 286 (8-9) ◽  
pp. 1049-1059 ◽  
Author(s):  
A. Bogner ◽  
A. Guimarães ◽  
R. C. O. Guimarães ◽  
A. M. Santos ◽  
G. Thollet ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Latex Particles

Natural Higher Fatty Acid Soaps in Natural Rubber Latex Concentrate and Correlations to Other Latex Variables

1986 ◽  
Vol 59 (1) ◽  
pp. 84-102 ◽  
Author(s):  
C. W. Jurado ◽  
K. G. Mayhan
Keyword(s):  
Fatty Acid ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Free Form ◽  
Rubber Latex ◽  
Rubber Phase

Abstract The amounts and types of HFA soaps found in latex did not vary greatly from sample to sample. Greater than 95% of the free HFA soaps were associated with the rubber phase of the latex. The distribution of fatty acid soaps were markedly different in the serum and latex samples. About 80–90% of the HFA soaps are in their free form, but only about 50% of the furanoic acid was in its free form. Titration results agree fairly well with the GC results and indicate that titration can be a useful measure of HFA.

Cytotoxicity and anticancer activity of natural rubber latex particles for cancer cells

2017 ◽  
Vol 5 ◽  
pp. 63-71 ◽  
Author(s):  
Mitsuru Furuya ◽  
Naoki Shimono ◽  
Kazuyuki Yamazaki ◽  
Ryota Domura ◽  
Masami Okamoto
Keyword(s):  
Natural Rubber ◽  
Anticancer Activity ◽  
Cancer Cells ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Latex Particles

Evidence for a Hydrochlorination Retarder within Natural-Rubber Latex Particles

1955 ◽  
Vol 28 (3) ◽  
pp. 918-921
Author(s):  
Manfred Gordon ◽  
James S. Taylor
Keyword(s):  
Natural Rubber ◽  
Chemical Nature ◽  
Natural Rubber Latex ◽  
Ion Pair ◽  
Retardation Effect ◽  
Rubber Latex ◽  
Constant Amount ◽  
Latex Particles ◽  
Basic Substance ◽  
Trace Substance

Abstract Kinetic evidence is presented for the occurrence in Hevea latex particles of a trace substance that retards the hydrochlorination reaction. No retardation effect is observed with synthetic polyisoprene latex. The chemical nature of the retarder in Hevea latex particles is not known, but it is likely to be a basic substance. Its retardation action reflects its power to deactivate the reactive precursor of the hydrochlorination reaction, which is interpreted as a form of ion pair (H+, Cl−). A constant amount of the precursor is deactivated by the retarder, irrespective of the temperature or the pressure of the hydrochlorination reaction.

A Concise Review on Design and Control of Structured Natural Rubber Latex Particles as Engineering Nanocomposites

2021 ◽  
pp. 110740
Author(s):  
Waraporn Wichaita ◽  
Duangkamol Promlok ◽  
Narissara Sudjaipraparat ◽  
Supang Sripraphot ◽  
Teeraporn Suteewong ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Latex Particles ◽  
Concise Review ◽  
And Control

A Method for Preparing Rubber Latex Specimens for the Electron Microscope

1947 ◽  
Vol 20 (2) ◽  
pp. 602-606 ◽  
Author(s):  
R. H. Kelsey ◽  
E. E. Hanson
Keyword(s):  
Electron Microscope ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Specimen Preparation ◽  
Electron Micrograph ◽  
Glass Capillary ◽  
Rubber Latex ◽  
Latex Particles ◽  
The Individual ◽  
Collodion Film

Abstract The preparation of natural and synthetic rubber latex specimens for examination with an electron microscope is difficult because the individual particles are easily deformed and, under the usual conditions of specimen preparation, the particles tend to agglomerate. Von Ardenne and Beischer and others used a method which consisted of depositing a drop of highly diluted latex on a collodion film and allowing the drop to dry completely. In some instances the drop was withdrawn again into a glass capillary. It was found that in either case the latex particles were flattened at their areas of contact with the collodion film. The collodion film method was tried in this laboratory with the same poor results observed by Hendricks, Wildman, and McMurdee. Figure 1 is an electron micrograph of a natural rubber latex particle deposited by evaporating latex diluted 200 to 1 on a collodion film. The film has broken and curled to give a profile view of the particle which is observed to be badly flattened at its area of contact with the film. Figure 2 is a typical electron micrograph of natural rubber latex particles deposited on a collodion film. The blurred outlines of the particles are explained by the effect shown in Figure 1. It was obviously impossible to make good particle-size measurements from micrographs of this type. It was found further that severe aggregation of particles usually took place when a drop of the diluted latex was dried down. The latex particles which were left behind when the drop was removed with a glass capillary usually were not badly agglomerated, but it was felt that there was some possibility that the latex particles might adhere selectively according to size to the collodion film. An attempt was made to reduce the amount of agglomeration by incorporating in the diluting water various amounts of such wetting or dispersing agents as sodium oleate, orvis paste, Aerosol-OT, and ammonium caseinate. None of these materials helped very much in reducing the agglomeration of particles. It was found also in this study that very often the latex particles appeared granular around their edges due to foreign material being swept in during the evaporation of the water and crystallizing out upon the surface of the particle. This effect may also be observed in Figure 1.

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