Structure of the Butadiene-Styrene Copolymer

1942 ◽  
Vol 15 (4) ◽  
pp. 693-697 ◽  
Author(s):  
E. N. Alekseeva ◽  
R. M. Belitzkaya
Keyword(s):  
Experimental Data ◽  
Formic Acid ◽  
Styrene Copolymer ◽  
Varied Structure ◽  
Butadiene Styrene

Abstract The experimental data indicate that joint polymerization of styrene and butadiene results in copolymers of varied structure. Of the styrene, 31.2 per cent forms, with the butadiene, macromolecules in which the two components alternate regularly, whereby the butadiene combines in its 1,4-position. Forty per cent of the styrene forms macromolecules, in which two units of styrene interlink adjacently. Such “styrene pairs” are separated by one or more molecules of butadiene polymerizing in their 1,4-position. The remaining 29 per cent of styrene evidently enters into the composition of branched macromolecules, formed as the result of butadiene linking both in the 1,2- and in the 1,4-positions. Taking into consideration the fact that formic acid must have been formed from macromolecules, with butadiene linked in the 1,2-position, we can conclude that 23.3 per cent of the butadiene polymerized in its 1,2-position, and the rest in the 1,4-configuration.

The Coagulation Mechanism of Butadiene—Styrene Latex

1959 ◽  
Vol 32 (2) ◽  
pp. 531-535 ◽  
Author(s):  
S. A. Glikman ◽  
E. P. Korchagina
Keyword(s):  
Experimental Data ◽  
Sodium Chloride ◽  
Nephelometric Method ◽  
Coagulation Mechanism ◽  
Aggregation Processes ◽  
Primary Particles ◽  
Two Stages ◽  
Latex Coagulation ◽  
Lyophobic Sols ◽  
Butadiene Styrene

Abstract 1. It is shown that the absolute values of the coagulation thresholds of SKS-30A latexes diluted down to 0.01% correspond to the usual values for lyophobic sols. The values for NaCl are 200 times those for CaCl2, and increase with the latex concentration. The complete coagulation concentration for NaCl is 30 times that for CaCl2, and does not depend on the dilution of the latex. 2. It was shown by a nephelometric method that the volume of the primary particles formed in coagulation of the latex by sodium chloride is about 10 times the volume of the uncoagulated latex globules, irrespective of the latex concentration. 3. Consideration of the experimental data, in conjunction with facts reported in the literature, leads to the concept of two stages in the coagulation of latex by electrolytes: the first is the consequence of a decrease of the zeta potential, leading to the formation of primary particles, and the second leads to coalescence of these particles. The secondary aggregation processes can be prevented or modified by introduction of certain additives (nonelectrolytes) into the latex. 4. In additon to an explanation of the mechanism of latex coagulation by electrolytes, and a demonstration that this process can be controlled, indications are given of means of an approach to development of conditions for the production of a good blanket by coagulation of latex by sodium chloride, with a much decreased consumption of the latter.

The Preservation of Latex by Acids

1937 ◽  
Vol 10 (4) ◽  
pp. 688-689
Author(s):  
Edgar Rhodes ◽  
K. C. Sekar
Keyword(s):  
Experimental Data ◽  
Formic Acid ◽  
Additional Experimental Data

Abstract It is shown that by the application to field latex of amounts of formic acid of the order of 9 per cent by weight of the latex or 10 per cent by volume of the 90 per cent commercial acid, a product results which will retain its fluidity for long periods. It is, however, apparently micro-flocculated, and unstable. Because of their instability, it seems unlikely that acid latices of this kind will find technical applications. The findings are in no way contradictory to those of Fullerton, whose experiments on coagulation did not include trials with such large amounts of acid. It is regretted that fuller experimental data cannot be given because most of the relevant records were destroyed recently by fire at the Institute. It is probable that a further study will be made, from which additional experimental data together with a possible explanation of the empirical observations given here may emerge.

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