EPDM rubber derivative

CLASS Chemical copolymers EPDM rubber derivatives... 

CLASS Chemical copolymers EPDM rubber derivatives STRUCTURE -(CH2-CH2) -(CH2-CH(CH3)) -... 

EPDM rubber - [ACRYLONITRILEPOLYMERS - SURVEY AND SAN (STYRENE-ACRYLONITRILECO-POLYMERS)] (Vol 1) -antioxidants for [ANTIOXIDANTS] (Vol 3) -for hydrazine storage [HYDRAZINE AND ITS DERIVATIVES] (Vol 13)... 

Homogeneous vanadium-based catalysts formed by the reaction of vanadium compounds and reducing agents such as organoaluminum compounds [10-12] are used industrially for the production of elastomers by ethylene/propene copolymerization (EP rubber) and ethylene/propene/diene terpolymerization (EPDM rubber). The dienes are usually derivatives of cyclopentadiene such as ethylidene norbomene or dicyclopentadiene. Examples of catalysts are Structures 1-4. Third components such as anisole or halocarbons are used to prevent a decrease in catalyst activity with time which is observed in the simple systems. 

Intermediate, enhanced oil recovery surfactants Benzene, mono-C10-13-alkyl derivs., distillation residues C12-14 alkylbenzene intermediate, EP additives 2-Ethyl hexyl erucate Octyl dodecyl erucate Tridecyl erucate intermediate, EP lubricants Benzene phosphorus oxydichloride intermediate, EPDM elastomers Dicyclopentadlene intermediate, EPDM rubbers N-(3-Aminopropyl) diethanolamine intermediate, epichlorohydrin Allyl chloride intermediate, epoxides C14-16 alpha olefin intermediate, epoxies... 

Competition between NR and bio-based SR (SR made from biosourced feedstock) should not be underestimated. For example in 2012, LANXESS is planning to produce the world s first SR, i.e. ethylene propylene diene monomer (EPDM) rubber (under the brand name of Keltan Eco) from ethylene derived from sugar cane at its Triunfo plant in Brazil. The ethanol is dehydrated into ethylene and polymerized to produce EPDM rubber." Besides, bio-based SR is suggested to be the bio-based feedstock of poly(butadiene) rubber for tyre industries. 

Butyl rubber (a copolymer of isobutylene and 1-3 mole per cent isoprene) and its halogenated derivatives have unsaturation in the carbon-carbon backbone and consequently do not have as good aging properties as EPDM. There are also reports (9-12) that ozone-resistant butyl rubber with a high degree of unsaturation can be prepared by copolymerization of isobutylene with either cyclopentadiene or 9-pinene. 

Rubbers are used mainly in the seals of packaging (i.e., for this, EPDM is used commonly, while nitrile polybutadiene rubber, and its derivates such as hydrogenated nitrile rubber and acrylates, fluoro-rubbers and silicones are all used for sealing oils and fuel containers, specifically). 

TTie chemistry of the accelerated vulcanization of BR, SBR, and EPDM appears to have much in common with the vulcanization of natural rubber Before the formation of crosshnks, the rubber is first sulfurated by accelerator-derived polysulfides (Ac-S -Ac) to give macromolecular, polysul-fidic intermediates (rubber-Sx-Ac). However, whereas in the case of MBTS-or benzothiazolesulfenamide-accelerated sulfur vulcanization of natural rubber, MBT is given off during the formation of rubber-Sx-BT from the attack of rubber by BT-S -BT, in the case of BR and SBR, MBT is not eliminated and remains unextractable presumably because it becomes bound as the macromolecular thioether rubber-S-BT. (BT is a 2-benzothiazolyl group.) As in the case of natural rubber, the average length of a crosslink (its sulfidic rank, the value of x in the crosslink, rubber-Sx-rubber) increases with the ratio of sulfur concentration to accelerator concentration (S/Ac) used in the... 

At ambient temperatures (0 to 40°C), TPOs have quite rubber-Uke properties. As the temperature is raised, however, these properties deteriorate quite sharply. On the other hand, the absence of unsaturation in the polymer backbones of both PP and EPDM makes these polymers and the TPOs derived from them very resistant to degradation by oxidation or ozone attack. The nonpolar nature of EPDM/PP TPOs makes them highly resistant to water, aqueous solutions, and other polar fluids such as alcohols and glycols, but they swell extensively with loss of properties when exposed to halocarbons and oils and fuels. 

Because of the low level of C=C imsatiu-ation in the polsrmer compared to, eg, natural rubber (NR) and SBR, EPDM needs significant amoimts of highly active accelerators for sulfur vulcanization. Usually, combinations of benzothiazole derivatives or sulfenamides with so-called ultra-accelerators like thiuram compoimds or dithiocarbamates are used. Because of the limited soluhihty of these various accelerators in EPDM versus the large quantities needed to obtain a sufficient level of vulcanization, an EPDM compoimd often contains four or more... 

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