scholarly journals Structural Characterization of Vulcanized Rubber by Pyrolysis-Gas Chromatography.

1998 ◽  
Vol 71 (2) ◽  
pp. 78-84
Author(s):  
TADAOKI OKUMOTO
Keyword(s):  
Gas Chromatography ◽  
Structural Characterization ◽  
Pyrolysis Gas ◽  
Pyrolysis Gas Chromatography ◽  
Vulcanized Rubber

Structural Characterization of Ethylene-Propylene-Diene Rubbers by High-Resolution Pyrolysis Gas Chromatography

1990 ◽  
Vol 63 (2) ◽  
pp. 191-201 ◽  
Author(s):  
T. Yamada ◽  
T. Okumoto ◽  
H. Ohtani ◽  
S. Tsuge
Keyword(s):  
Gas Chromatography ◽  
Structural Characterization ◽  
Fused Silica ◽  
Sequence Length ◽  
Spectroscopic Methods ◽  
Pyrolysis Gas ◽  
Ethylene Propylene ◽  
Pyrolysis Gas Chromatography ◽  
Diene Rubbers

Abstract Ethylene-propylene-diene rubbers (EPDMs) are now used for various purposes because of their excellent resistance to ozone, weather, and heat. Therefore, many kinds of EPDMs are provided as commercial polymers. Consequently, reliable methods for the structural characterization of EPDM have been needed in the fields of material development, process control, and quality assurance of the cured products. The iodine value method is generally used to determine the diene content in EPDMs. However, it is too time consuming to be a routine method. Until now, spectroscopic methods such as IR and NMR are generally used for the study of the composition and the sequence length distributions in EPDMs. Levine and Haines determined the content of ethylidenenorbornene (ENB) in ethylene-propylene-ethylidenenorbornene rubbers (ENB-EPDMs) by IR. Florence and Loustalot investigated ethylene-propylene-1.4-hexadiene rubbers by NMR. However, these spectroscopic methods often encountered the difficulties in the analysis of vulcanized rubbers since they were insoluble and usually contained many kinds of additives such as curing agents, plasticizers, stabilizers, and fillers. On the other hand, owing to the recent development of excellent pyrolyzers and highly efficient fused-silica capillary columns, pyrolysis-gas chromatography (PyGC) has become a powerful tool to give unique information about structures of high polymers. Furthermore, PyGC is advantageous to the practical analysis of insoluble polymeric materials such as vulcanized rubbers.

Characterization of Vulcanized EPDM Rubbers by High-Resolution Pyrolysis Gas Chromatography

1991 ◽  
Vol 64 (5) ◽  
pp. 708-713 ◽  
Author(s):  
T. Yamada ◽  
T. Okumoto ◽  
H. Ohtani ◽  
S. Tsuge
Keyword(s):  
Gas Chromatography ◽  
High Resolution ◽  
Degradation Products ◽  
Polymeric Materials ◽  
Pyrolysis Gas ◽  
Ethylene Propylene ◽  
Pyrolysis Gas Chromatography ◽  
Vulcanized Rubber ◽  
Thermal Degradation Behavior

Abstract Pyrolysis gas chromatography (PyGC) is a powerful tool to give unique information of high polymers. Especially, PyGC is favorable for the practical analysis of insoluble polymeric materials such as vulcanized rubbers. In the previous paper, the structures of commercially available unvulcanized ethylene-propylene-ethylidenenorbornene rubbers (ENB-EPDMs) were investigated by high-resolution PyGC. The observed high-resolution pyrograms of the unvulcanized EPDMs were correlated to the ENB content. In addition, several peaks of the characteristic degradation products were interpreted in terms of the sequence distribution and the ethylene-propylene composition. In this work, vulcanized ENB-EPDMs (V-EPDMs) cured with two types of vulcanizing agents were studied using high-resolution PyGC. Characteristic pyrolysis products formed at 650°C were separated by the high-resolution capillary column, and the resulting pyrograms were interpreted in terms of ENB content in the vulcanized rubber samples. In addition, thermal degradation behavior of the ENB units in V-EPDMs was investigated.

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