The Preparation of Cyclized Rubber from Natural-Rubber Latex

1951 ◽  
Vol 24 (1) ◽  
pp. 195-196
Author(s):  
G. J. van Veersen
Keyword(s):  
Experimental Study ◽  
Sulfuric Acid ◽  
Natural Rubber ◽  
Hydrogen Chloride ◽  
Hydrogen Fluoride ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Boron Fluoride ◽  
Surface Active Agents ◽  
Surface Active

Abstract The hydrochlorination of rubber in the form of latex which has been stabilized by surface-active agents, such as Emulphor-O, or by cationic agents such as Fixanol, shows that hydrogen chloride molecules diffuse very easily into the latex globules. Accordingly it was to be expected that, by replacing hydrogen chloride gas by hydrogen fluoride gas, which is a cyclizing agent of rubber, a cyclized rubber would be obtained. This line of reasoning was confirmed experimentally. As a result of an experimental study, it was proved that boron fluoride, BF8 also, brings about cyclization of rubber in latex, and van Amerongen has already shown that sulfuric acid likewise can be used as a catalyst. Since sulfuric acid is much easier to handle than either hydrogen fluoride or boron fluoride, it was used in most of the experiments in the present work.

Rheological behavior of natural rubber latex in the presence of surface-active agents

1990 ◽  
Vol 41 (56) ◽  
pp. 975-983 ◽  
Author(s):  
N. R. Peethambaran ◽  
Baby Kuriakose ◽  
Manjari Rajan ◽  
A. P. Kuriakose
Keyword(s):  
Natural Rubber ◽  
Rheological Behavior ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Surface Active Agents ◽  
Surface Active

scholarly journals Pengaruh Konsentrasi Asam Sulfat (H2SO4) pada Hidrolisa Tongkol Jagung (Zea mays) Menjadi Nanokristal Selulosa sebagai Filler Penguat pada Produk Lateks Karet Alam

2019 ◽  
Vol 8 (2) ◽  
pp. 48-53
Author(s):  
Hamidah Harahap ◽  
Azwin Harfansah Nst ◽  
Ilhamdi Fujian Junaidi
Keyword(s):  
Sulfuric Acid ◽  
Natural Rubber ◽  
Physical Properties ◽  
Mechanical Test ◽  
Natural Rubber Latex ◽  
Spherical Shape ◽  
Rubber Latex ◽  
Hydrolysis Process ◽  
Cross Connect ◽  
Vulcanization Process

This research studied about the effect of concentrations sulfuric acid (H2SO4) on the hydrolysis process of corn cobs waste to manufacture of cellulose nanocrystal (NCC) which will be applied as fillers in natural rubber latex. This study began with a pre-vulcanization process of natural rubber latex at a temperature of 70 oC and followed by a vulcanization process at 110 oC for 10 minutes. The results of the testing of physical properties indicate that the higher amount of NCC loading will result in higher crosslinked denotes, while the results of testing the mechanical properties indicate that the maximum value is achieved at the loading of NCCs as much as 6 phr. The mechanical test results supported by the analysis of Scanning Electron Microscopy (SEM) showing the NCC have spread well. Characterization of the Transform Electron Microscope (TEM) shown  the resulting of NCC was spherical shape with the size of NCC produced for each concentration of sulfuric acid (H2SO4) 45%, 55%, and 65% respectively 57.65 nm; 28.43 nm; and 82.61 nm with an amount of each 0.849 g; 1,824 g; and 0.681 g. The mechanical and physical properties of the optimum natural rubber latex products occurred in the loading of nanocrystal cellulose with a number of 6 bsk, where the values ​​of cross-connect density, tensile strength, elongation at break, M200 and M300 were respectively 10.6234 2Mc-1x10- 5; 18.2 MPa; 780%; 2.23 MPa and 2.7 MPa.

The Polymerization of Vinyl Monomers in Natural-Rubber Latex

1956 ◽  
Vol 29 (4) ◽  
pp. 1119-1126 ◽  
Author(s):  
George F. Bloomfield ◽  
P. McL. Swift
Keyword(s):  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Vinyl Monomers ◽  
Rubber Latex ◽  
Dispersing Agent ◽  
Rubber Particles ◽  
Surface Active ◽  
Active Substances

Abstract Practical methods are described for polymerizing methacrylic esters, styrene, and other vinyl monomers in natural-rubber latex. The larger rubber particles require an appreciable time to attain equilibrium with the monomer diffusing into them from a liquid monomer phase dispersed in the serum. Provided that substantial proportions of added surface-active substances are avoided, rubber-soluble monomers can be polymerized almost entirely within the rubber particles, and the modified latex then contains no separately emulsified free polymer. Such conditions favor combination of polymer with rubber. The addition of a sufficiently large amount of dispersing agent favors polymerization of emulsified monomer, with less involvement of the rubber. In this way there can be obtained mixtures of rubber and polymer from monomers whose polymerization is otherwise inhibited by the presence of polyisoprene hydrocarbons.

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