Nitrile rubber hydrogenated

Table 6. World Production Facilities for Hydrogenated Nitrile Rubber ...

S. Hayashi, M. Oyama, K. Hashimoto, and T. Nakagawa, "New Improved Low Temperature Hydrogenated Nitrile Rubber (HNBR)," paper presented at theH.CA. Racbber Division Meeting, Detroit, Mich., Oct. 8—11,1991. 

Hydrogenated nitrile rubbers were introduced in the mid-1980s as Therban by Bayer. The initial grade had an acrylonitrile content of only 17% instead of approx. 34% in conventional NBR. Whilst non-sulphur-curing systems such as the use of peroxides with triallyl cyanurate or isocyanurate are necessary, the saturated rubber has a number of advantages over NBR. These include improved... 

Polynorbomene (PNR), polyoctenamer and hydrogenated nitrile rubber (HNBR)—this chapter... 

This chapter mainly aims at describing the various methods and processes developed for hydrogenation of nitrile rubber. The characterization, physical properties, and application of hydrogenated nitrile rubber are also discussed. Another small section on hydroformylation of nitrile rubber has been included. 

The value of AG° at various reaction temperatures and corresponding Kp values are reported in Table 2. It can be understood from Table 2 that the formation of hydrogenated nitrile rubber from nitrile rubber is thermodynamically feasible. 

The research in this area has a great potential from scientific and technological aspects and requires further exploration. However, the reported attempts are a welcoming endeavor to hydrogenate nitrile rubber in latex form. 

Hydrogenated nitrile rubber is much more stable than NBR at elevated temperature. Bhattacharjee et al. [134] performed a high-temperature degradation (30-800°C) of HNBR and NBR in nitrogen atmosphere... 

Elastomer types used successfully in these areas are natural rubber (NR), polychloroprene (CR), and nitrile rubber (NBR), and hydrogenated nitrile rubber (HNBR), where oil resistance is also required. 

W02005/080456 Al, Lanxess Inc. Process for the preparation of low molecular weight hydrogenated nitrile rubber EP2028194 Al, Lanxess Deutschland GmbH Metathesis of nitrile rubbers in the presence of transition metal complex catalysts Press release Lanxess - New York Conference, New York City, USA, Monday August 28, 2006, Address by Dr. Ulrich Koemm LANXESS Concepts in Rubber ... 

Chemical modification of polymers continues to be an active field of research [1-5]. It is a common means of changing and optimising the physical, mechanical and technological properties of polymers [5-7]. It is also a unique route to produce polymers with unusual chemical structure and composition that are otherwise inaccessible or very difficult to prepare by conventional polymerisation methods. For example, hydrogenated nitrile rubber (HNBR) which has a structure which resembles that of the copolymer ethylene and acrylonitrile, is very difficult to prepare by conventional copolymerisation of the monomers. Polyvinyl alcohol can only be prepared by hydrolysis of polyvinyl acetate. Most of the rubbers or rubbery materials have unsaturation in their main chain and/or in their pendent groups. So these materials are very susceptible towards chemical reactions compared to their saturated counterparts. 

Relevant systems are mbber-toughened epoxy resins, high-impact acrylic (PMMA particles in mbber matrix, obtained by radical polymerization of 80/20 MMA/EVAc mixture), polyimide/silica hybrid materials (obtained using the sol-gel method), and a very high strength ( 60 MPa) mbbers (obtained by peroxide cure of a hydrogenated nitrile rubber/ zinc dimethacrylate system) [Inoue, 1995]. 

Both polychloroprenes, M and N, and hydrogenated nitrile rubber N2 showed an upturn in strength at the highest temperature only, indicating the onset of a different mechanism. The nitrile P showed this at 90 °C and 100 °C but it was followed by a downturn in strength at 100 °C. The nitrile R had a somewhat curious scatter of results at 70 °C. 

There was indication of cyclic behaviour for the hydrogenated nitrile rubber N2, chlorinated polyethylene N4, nitrile rubber P4 and Vamac material P6. Compounds N2 and P6 appeared to have maxima, followed by a minimum in the case of compound P6. Compounds N4 and P4 possibly had minima. The tensile strength of compound N5 apparently changes direction falling slightly in strength at 150 °C then rising at 210 °C. 

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