Rubber, raw styrene-butadiene, emulsion-polymerized. Determination of bound styrene content. Refractive index method

2020 ◽  
Keyword(s):  
Refractive Index ◽  
Index Method ◽  
Styrene Content ◽  
Styrene Butadiene

Determination of Copolymer Composition by Combustion Analysis for Carbon and Hydrogen

1960 ◽  
Vol 33 (4) ◽  
pp. 1132-1141
Author(s):  
Lawrence A. Wood ◽  
Irving Madorsky ◽  
Rolf A. Paulson
Keyword(s):  
Refractive Index ◽  
Present Method ◽  
Copolymer Composition ◽  
Combustion Analysis ◽  
Physical Methods ◽  
Accuracy And Precision ◽  
Styrene Content ◽  
The One ◽  
Relative Measurements

Abstract The procedure described attains its accuracy and precision by the refinement and improvement of conventional simple operations over a periods of years. The trend in analysis recently is, of course, toward the use of rapid physical methods. In a great many instances these involve relative measurements requiring the initial establishment of reference materials with compositions determined by methods such as the one here described, which bases the numbers derived solely on readings of an analytical balance. In fact, as already mentioned, one of the principal applications of the present method has been in the establishment of the relation between refractive index and styrene content for SBR polymers so that refractive index measurements can be used in routine determinations of bound styrene content.

A Study of the Thermal Degradation Products of Styrene-Butadiene Type Rubber by Pyrolysis/GC/MS

1996 ◽  
Vol 69 (5) ◽  
pp. 874-884 ◽  
Author(s):  
Ghebrehiwet N. Ghebremeskel ◽  
J. K. Sekinger ◽  
J. L. Hoffpauir ◽  
C. Hendrix
Keyword(s):  
Refractive Index ◽  
Infrared Spectroscopy ◽  
Thermal Degradation ◽  
Degradation Products ◽  
Ease Of Use ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Thermal Degradation Products ◽  
Styrene Content ◽  
Styrene Butadiene

Abstract Pyrolysis coupled with GC/MS was used to study thermal degradation products of styrene—butadiene rubber (SBR). Introduction of samples, using the pyrolysis carrier gas through the split injection port, followed by sub-ambient focusing of pyrolysis products gave reproducible chromatograms. The styrene content of styrene—butadiene copolymer was determined by plotting the GC areas of styrene and butadiene dimer (4-vinlycyclohexene) vs the percent bound styrene measured by refractive index and infrared spectroscopy. The accuracy and ease of use of the technique in determining the styrene content of styrene—butadiene copolymer is also compared to that of the refractive index and infrared spectroscopy methods. Finally, the effects of carbon black and other fillers on the thermal degradation products of the styrene—butadiene copolymer are also discussed.

Determination of Ethylidenenorbornene in EPDM Terpolymers

1973 ◽  
Vol 46 (4) ◽  
pp. 1019-1034 ◽  
Author(s):  
I. J. Gardner ◽  
G. Ver Strate
Keyword(s):  
Refractive Index ◽  
Physical Property ◽  
Side Reactions ◽  
Time Averaging ◽  
Absorption Bands ◽  
Index Method ◽  
Carbon 14 ◽  
Compositional Variations ◽  
Catalyst Systems

Abstract Ethylidenenorbornene (ENB) is a diene often employed as the third monomer in the commercial production of ethylene-propylene terpolymers (EPDM). A number of spectroscopic, chemical, and physical property procedures were examined as potential methods for determining ENB content. These included the use of iodine monochloride (ICI) and borane chemistry, nuclear magnetic resonance (NMR), and infrared (IR) analyses, as well as refractive index determinations. To evaluate the accuracy and reproducibility of the various methods, we prepared 24 EPDM terpolymers containing carbon-14 labeled ENB. The labeled diene was prepared via the Wittig synthesis. The ENB content of the EPDM's varied from 1.17 to 17.40 weight per cent. Catalyst systems for terpolymer preparation were employed that were representative of those used commercially in the production of EPDM. The refractive index method was found to combine adequate precision with speed of operation and proved to be the most reliable of the methods studied for determination of ENB content. An iodine number method was equally precise but suffered from the standpoint of speed. Two IR methods employing the 1685 cm−1 and 805 cm−1 absorption bands were not acceptable because of various structural interferences arising from compositional variations within the polymers. Proton NMR requires the use of time averaging and borane. chemistry proves to be a more cumbersome wet method than ICI, although presumably it involves reactions with olefins less complicated by side reactions than with ICI. Interrelationships of the various techniques are examined with regard to information concerning branching reactions. It is concluded that the data are consistent with the idea that commercial EPDM is a highly branched, partially gelled polymer. The basic contribution here is the refractive index technique which we referred to previously.

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