Acrylonitrile Butadiene Rubbers

Nanocomposites have been prepared with this polymer and mechanical and barrier properties and ffacmre behavior have been studied [74—76]. The latex of this mbber has also been used for the same [77]. Sadhu and Bhowmick [78-81] have studied the preparation, stmcmre, and various 

Mechanical Properties with Varying Degrees of Polarity of Rubber 

Sample Strength Elongation Break Elongation Modulus X 10 Volume 

Source Sadhu, S. and Bhowmick, A.K., J. Polym. Set, Part B Polym. Phys., 42, 1573, 2004. Courtesy of Wiley 

19NBROC4 = nitrile rubber with 19% acrylonitrile + 4 phr octadecyl amine modified MMT, 19NBRN4 = nitrile rubber 

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Acrylonitrile-butadiene rubber (also called nitrile or nitrile butadiene rubber) was commercially available in 1936 under the name Buna-N. It was obtained by emulsion polymerization of acrylonitrile and butadiene. During World War II, NBR was used to replace natural rubber. After World War II, NBR was still used due to its excellent properties, such as high oil and plasticizer resistance, excellent heat resistance, good adhesion to metallic substrates, and good compatibility with several compounding ingredients. 

In the past chemical cure linings have been employed on a wide scale. These linings, usually based on natural rubber or acrylonitrile-butadiene rubber consist of a standard lining compound with a chemical activator such as dibenzylamine incorporated in the formulation. Prior to the application of the lining to the substrate, the individual sheets of rubber are dipped or brush coated with carbon disulphide or a solution of a xanthogen disulphide in a solvent. The carbon disulphide or xanthogen disulphide permeates the rubber and combines with the dibenzylamine to form an ultra-fast dithiocar-bamate accelerator in situ, and thus the rubber rapidly vulcanises at ambient temperature. 

In more recent years, lining compounds have been developed that vulcanise at ambient temperatures. Most polymers can be used for such compounds, although most materials are based on natural rubber, acrylonitrile-butadiene rubber and polychloroprene. These compounds contain accelerators which usually give rise to a material which has a delay in the onset of vulcanisation with a subsequent rapid rise in cross-link formation to give full vulcanisation in 6 to 8 weeks. Such materials, unless to be used within a few days of manufacture, are refrigerated to arrest the sel f-vulcanisation. 

Polychloroprene and acrylonitrile-butadiene rubber compounds have satisfactory chemical resistance but, except for phosphoric acid, are not suitable for mineral acids at higher concentrations. However, they have good resistance to oils, acrylonitrile-butadiene rubber being the better, and so are often used in oil-contaminated aqueous environments. Generally, abrasion resistance is only fair. Normal maximum working temperature is about 100°C. Acrylonitrile-butadiene rubber ebonites are sometimes used especially where solvent contamination occurs, but are normally very brittle and so should be used with care. 

FIGURE 2.8 Transmission electron microscopy (TEM) photographs of clay nanocomposites with acrylonitrile-butadiene rubber (NBR) having (a) 50% and (b) 19% acrylonitrile content, respectively... 

Frenkel R., Duchacek V., Kirillova T., and Kuz min E. Thermodynamic and structural properties of acrylonitrile butadiene rubber/polyethylene blends, J. Appl. Polym. Sci., 34, 1301, 1987. 

Pandey et al. have used ultrasonic velocity measurement to study compatibility of EPDM and acrylonitrile-butadiene rubber (NBR) blends at various blend ratios and in the presence of compa-tibilizers, namely chloro-sulfonated polyethylene (CSM) and chlorinated polyethylene (CM) [22]. They used an ultrasonic interferometer to measure sound velocity in solutions of the mbbers and then-blends. A plot of ultrasonic velocity versus composition of the blends is given in Eigure 11.1. Whereas the solution of the neat blends exhibits a wavy curve (with rise and fall), the curves for blends with compatibihzers (CSM and CM) are hnear. They resemble the curves for free energy change versus composition, where sinusoidal curves in the middle represent immiscibility and upper and lower curves stand for miscibihty. Similar curves are obtained for solutions containing 2 and 5 wt% of the blends. These results were confirmed by measurements with atomic force microscopy (AEM) and dynamic mechanical analysis as shown in Eigures 11.2 and 11.3. Substantial earher work on binary and ternary blends, particularly using EPDM and nitrile mbber, has been reported. 

Naskar, M., Debnath, S.C., and Basu, D.K. Effect of Bis (Diisopropyl) Thiophosphoryl Disulfide on the Co-Vulcanization of Carboxyhc Acrylonitrile Butadiene Rubber and Ethylene Propylene Diene Rubber Blends. Rubber Chem. Technol. 75(3), 309-322, July/August 2002. 

FIGURE 38.8 Ambient ground acrylonitrile butadiene rubber (NBR) waste powder. (Reprinted from Anandhan, S., De, P.P., Bhowmick, A.K., Bandyopadhyay, S., and De, S.K., J. Appl. Polym. Sci., 90, 2348, 2003. With permission from Wiley InterScience.)... 

Zinc peroxide is used as the curative for carboxylated acrylonitrile-butadiene rubber (XNBR) compounds. It confers better scorch safety than does zinc oxide. It is usually added in a masterbatch form. 

This method involves the mechanical blending of styrene-acrylonitrile copolymers and acrylonitrile-butadiene rubbers. Many products are possible depending on the composition of each copolymer and the relative amounts employed. 

In an example 70 parts (70 30 styrene acrylonitrile-copolymer) gets blended with 40 parts (35 65 acrylonitrile butadiene rubber). After it gets blended, the coagulation of the polymer is brought about by adding an acid or salt. 

Support the ongoing business of elastomer of the associated market segments and regions, Knowledge of different type of rubber NBR (Acrylonitrile Butadiene rubber), SBR, PBR, EPDM, HSBR, HBR and application in different filed like tire industries, plastic industries, Adhesive, An effective researcher/ manager with excellent designing and presentation skills... 

PS (polystyrene), PVC [poly(vinyl chloride)], PC (bisphenol A polycarbonate) PMMA [poly (methyl methacrylate)], PB (polybutadiene), SAN (styrene-acrylonitrile copolymer),NBR (acrylonitrile-butadiene rubber), PPE (polyphenylene ether), SBR (styrene-butadiene rubber)... 

Other compatible commercial systems are as follows polystyrene (PS) and polyphenylene oxide (PPO) polyvinyl chloride (PVC) and nylon 66 PVC and acrylonitrile-butadiene rubber (NBR) and PS and polycarbonate (PC) (up to 60% PC). 

For example, the volume change of an acrylonitrile-butadiene rubber (NBR)40 sample at X = 2 relative to the volume of its undeformed state was about 5 x 10 4, and the values for the other vulcanizates were less than this. We therefore assumed that the use of Eqs. (34) and (35) is warranted for the computation of dW/dlt for our rubber samples, except at very small deformations for which// < 3.02. In most cases, stress relaxation was allowed to proceed at given stretch ratios and 1- and 10-min isochronal stress values were taken for the calculations. 

The polymers described above have been chemically pure, although physically helerodisperse. It is oflen possible lo combine two or more of these monomers in the same molecule to form a copolymer. This process produces still further modification of molecular properties and, in turn, modification of the physical properties of file product. Many commercial polymers are copolymers because of the blending of properties achieved in this way. For example, one of the important new polymers of the past ten years has been the family of copolymers of acrylonitrile, butadiene and styrene, commonly called ABS resins. The production of these materials has grown rapidly in a short period of time because of their combination of dimensional stability and high impact resistance. These properties are related to the impact resistance of acrylonitrile-butadiene rubber and the dimensional stability of polystyrene, which are joined in the same molecule. 

A few studies have reported the embedding of an MIP film between two membranes as a strategy for the construction of composite membranes. For example, a metal ion-selective membrane composed of a Zn(II)-imprinted film between two layers of a porous support material was reported [253]. The imprinted membrane was prepared by surface water-in-oil emulsion polymerisation of divinylbenzene as polymer matrix with 1,12-dodecanediol-0,0 -diphenylphosphonic acid as functional host molecule for Zn(II) binding in the presence of acrylonitrile-butadiene rubber as reinforcing material and L-glutamic acid dioleylester ribitol as emulsion stabiliser. By using the acrylonitrile-butadiene rubber in the polymer matrix and the porous support PTFE, an improvement of the flexibility and the mechanical strength has been obtained for this membrane. 

ABA ABS ABS-PC ABS-PVC ACM ACS AES AMMA AN APET APP ASA BR BS CA CAB CAP CN CP CPE CPET CPP CPVC CR CTA DAM DAP DMT ECTFE EEA EMA EMAA EMAC EMPP EnBA EP EPM ESI EVA(C) EVOH FEP HDI HDPE HIPS HMDI IPI LDPE LLDPE MBS Acrylonitrile-butadiene-acrylate Acrylonitrile-butadiene-styrene copolymer Acrylonitrile-butadiene-styrene-polycarbonate alloy Acrylonitrile-butadiene-styrene-poly(vinyl chloride) alloy Acrylic acid ester rubber Acrylonitrile-chlorinated pe-styrene Acrylonitrile-ethylene-propylene-styrene Acrylonitrile-methyl methacrylate Acrylonitrile Amorphous polyethylene terephthalate Atactic polypropylene Acrylic-styrene-acrylonitrile Butadiene rubber Butadiene styrene rubber Cellulose acetate Cellulose acetate-butyrate Cellulose acetate-propionate Cellulose nitrate Cellulose propionate Chlorinated polyethylene Crystalline polyethylene terephthalate Cast polypropylene Chlorinated polyvinyl chloride Chloroprene rubber Cellulose triacetate Diallyl maleate Diallyl phthalate Terephthalic acid, dimethyl ester Ethylene-chlorotrifluoroethylene copolymer Ethylene-ethyl acrylate Ethylene-methyl acrylate Ethylene methacrylic acid Ethylene-methyl acrylate copolymer Elastomer modified polypropylene Ethylene normal butyl acrylate Epoxy resin, also ethylene-propylene Ethylene-propylene rubber Ethylene-styrene copolymers Polyethylene-vinyl acetate Polyethylene-vinyl alcohol copolymers Fluorinated ethylene-propylene copolymers Hexamethylene diisocyanate High-density polyethylene High-impact polystyrene Diisocyanato dicyclohexylmethane Isophorone diisocyanate Low-density polyethylene Linear low-density polyethylene Methacrylate-butadiene-styrene... 

Acrylonitrile-Butadiene Rubbers (NBR). Acrylonitrile-butadiene rubbers (NBR), or simply nitrile rubbers, are copolymers of butadiene and acrylonitrile. They are available in five grades based on the acrylonitrile (ACN) content. 

The glass transition temperatures of polyacrylonitrile at +90°C and of polybutadiene at -90°C differ considerably therefore, with an increasing amount of acrylonitrile in the polymer, the Tg temperature of NBR rises together with its brittleness temperature. The comonomer ratio is the single most important recipe variable for the production of acrylonitrile-butadiene rubbers. 

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