Degradation of hydrogenated nitrile rubber

Bhattacharjee, Sukanta; Bhowmick, Anil K.; Avasthi, B. N.

doi:10.1016/0141-3910(91)90097-b

Cited by 75 publications

(44 citation statements)

References 10 publications

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“…The small increase in MW at 260°C might have been caused by crosslinking at the (-C'N) group, which was suggested to be converted to (-CANH). 8 Crosslinking can also occur as a result of oxidative addition reaction at the double bond of the diene part. However, the increase in molecular weight is very small and this sample can generally be considered highly stable.…”

Section: Extent Of Degradationmentioning

confidence: 99%

“…Very few studies raised the question of influence of molecular structure and processing conditions on degradation of raw, uncured NBR. 3,8 For example, Bhattacharjee et al used TGA to investigate low-(75-150°C) and high-temperature (800°C) degradation of HNBRs and reported generation of ester (-COOR) and carbonyl groups (-CAO). 8 For highly saturated nitrile rubber, an increase in molecular weight (MW) was observed, whereas a decrease in MW was reported for NBR.…”

Section: Introductionmentioning

confidence: 98%

“…3,8 For example, Bhattacharjee et al used TGA to investigate low-(75-150°C) and high-temperature (800°C) degradation of HNBRs and reported generation of ester (-COOR) and carbonyl groups (-CAO). 8 For highly saturated nitrile rubber, an increase in molecular weight (MW) was observed, whereas a decrease in MW was reported for NBR. The increase in MW of saturated nitrile rubbers was suggested to be caused by the conversion of the (-C'N) group to (-CANH).…”

Section: Introductionmentioning

confidence: 98%

“…8 Sarkar et al 3 investigated the degradation of hydrogenated styrene-butadiene rubber (HSBR) using TGA analysis, DSC, IR, and NMR spectroscopy. HSBR was found to be more stable than SBR in nitrogen atmosphere.…”

Section: Introductionmentioning

confidence: 99%

“…7 Extensive studies regarding nitrile buta-diene rubber (NBR) are available in the literature where stability of NBR and hydrogenated NBR (HNBR) has been investigated under different operating conditions and numerous techniques such as thermogravimetry, IR, DSC, FTIR, SEM, and rheology were used for this purpose. 8,3 However, most of the studies on degradation have focused on rubber/rubber and rubber/plastic blends. 9 -14 Studies on degradation of pure raw rubber have been limited to natural rubber.…”

Section: Introductionmentioning

confidence: 99%

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Influence of molecular parameters and processing conditions on degradation of hydrogenated nitrile butadiene rubbers

Chaudhry

Hussein

Amin

et al. 2005

J of Applied Polymer Sci

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ABSTRACT:The thermomechanical modification of hydrogenated nitrile butadiene rubbers (HNBR) of different molecular parameters was investigated by rheological and light scattering techniques. The influences of acrylonitrile content, degrees of hydrogenation, and Mooney viscosity were examined. A melt blender with Banbury-type mixing blades was used to condition the rubber samples in the temperature range from 190 to 260°C. Light scattering was used to determine the effect of conditioning on MW and hydrodynamic radius of the rubber molecules. Dynamic viscosity (Ј) and storage modulus (GЈ) were measured for the as-received and conditioned samples. Experimental results showed that degradation in these rubbers occurred through chain scission and crosslinking. Depending on the molecular parameter, it was found that one of these two mechanisms dominated the degradation process in most brands. Addition of adequate amounts of antioxidants (Irganox 1010 and Irgafos 168) was successful only in preventing degradation by crosslinking. Compared to thermal degradation, thermomechanical degradation was found to be much more severe and progressed at much higher rates. Rheology was found to be a very sensitive technique to structural parameters of the polymers and could be used to detect and identify the mechanism of degradation.

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Section: Extent Of Degradationmentioning

confidence: 99%