Acrylonitrile-butadiene copolymers with styrene

ANs are those that contain a majority of nitrile polymers. They provide good gas barrier, chemical resistance, and low taste and odor transfer with good impact properties when modified with rubber. Extruded sheet is used extensively in food packaging and rigid packaging applications. This crystalline TP is most useful in copolymers. Its copolymer with butadiene is nitrile rubber. Acrylonitrile-butadiene copolymers with styrene (SAN) exist that are tougher than PS. It is also used as a synthetic fiber and as a chemical intermediate. 

Styrene Copolymers. Acrylonitrile, butadiene, a-methylstyrene, acryUc acid, and maleic anhydride have been copolymerized with styrene to yield commercially significant copolymers. Acrylonitrile copolymer with styrene (SAN), the largest-volume styrenic copolymer, is used in appHcations requiring increased strength and chemical resistance over PS. Most of these polymers have been prepared at the cross-over or azeotropic composition, which is ca 24 wt % acrylonitrile (see Acrylonithile polya rs Copolyp rs). 

The term ABS was originally used as a general term to describe various blends and copolymers containing acrylonitrile, butadiene and styrene. Prominent among the earliest materials were physical blends of acrylonitrile-styrene copolymers (SAN) (which are glassy) and acrylonitrile-butadiene copolymers (which are rubbery). Such materials are now obsolete but are referred to briefly below, as Type 1 materials, since they do illustrate some basic principles. Today the term ABS usually refers to a product consisting of discrete cross-linked polybutadiene rubber particles that are grafted with SAN and embedded in a SAN matrix. 

Copolymers of itaconic esters with butadiene have not yet been used technically. On the other hand, acrylonitrile containing copolymers with other components have been studied from several points of view. Standard Oil Co. has claimed a terpolymer of isobutylene, butadiene, and acrylonitrile, and BASF a similar product of butadiene, acrylonitrile, and styrene. The films from these combinations are said to have high flexibility and cold resistance. However, all butadiene containing copolymers are not light fast. Copolymers of butadiene, acrylonitrile, and unsaturated dicarboxylic esters are suggested for plasticizing PVC, but they must be thermally degraded before they are combined with the polymer. 

Sonic Modulus. If crack or craze branching is the operative mech-nism in toughening, toughness should be directly related to the difference in sonic speeds in matrix and dispersed phases. Experiments to confirm this effect were undertaken using three commercial ABS resins. These were selected to represent the three main rubber types encountered commercially an acrylonitrile/butadiene copolymer rubber, a butadiene rubber with grafted styrene/acrylonitrile copolymer, and a block polymer of... 

ABS and Related Materials. The so-called ABS (acrylonitrile-buta-diene-styrene—monomers 1, 2, and 3) materials comprise a class of compounds that consists of either blends or grafts (41). All have three monomers divided between two different polymers in a 1,2 and 1,3 combination mode. Blends of styrene-butadiene (1,2) random copolymers with styrene-acrylonitrile (1,3) random copolymers result in toughened plastics the common-mer, styrene, improves compatibility. The material may be described ... 

Butadiene (bpI o13= — 4-413°C, d4°=0.621 l)(l> has become a major petrochemical product thanks to the development of its copolymers with styrene and acrylonitrile. The earliest processes for manufacturing butadiene started with acetylene and formaldehyde (Germany, the Reppe process), or produced it by the aldolization of acetaldehyde (Germany), or by the dehydration and dehydrogenation of ethanol (USSR, United States Union Carbide),... 

In 1983, Monsanto developed blends with co-continuous morphology, Triax 2000. These alloys comprised PC, ABS, and styrene-methylmethac-rylate-maleic anhydride (SMMA-MA) [Jones and Mendelson, 1985]. One year later, PC was reactively blended with either ABS, SAN-GMA, and NBR, or with graft copolymers of acrylonitrile-butadiene-a-methyl styrene-methyl-methacrylate (MeABS) and acryloiutrile-a-methyl styrene-methyl methacrylate copolymer (MeSAN) [Kress et al., 1986]. The blends were commercialized by Bayer as Bayblend . 

Methyl methacrylate has been copolymerized with a wide variety of other monomers, such as acrylates, acrylonitrile, styrene, and butadiene. Copolymerization with styrene gives a material with improved melt-flow characteristics. Copolymerization with either butadiene or acrylonitrile, or blending PMMA with SBR, improves impact resistance. Butadiene-methyl methacrylate copolymer has been used in paper and board finishes. 

Poly BD marketed by Atochem North America, Inc. is a family of hydroxyl-terminated butadiene homopolymers and copolymers with styrene or acrylonitrile. These materials are usually reacted with isocyanates to produce pol)mrethanes that have excellent resistance to boiling water. 

High molecular weight homopolymers of 1,3-butadiene formed by a free-radical mechanism lack the type of elastomeric properties that are needed from commercial rubbers. Copolymers of butadiene, however, with styrene or acrylonitrile are more useful and are prepared on a large scale. This is discussed in another section. 

Acrylonitrile-butadiene rubber, NBR, styrene-aciylonitrile rubber, SAN, ethylene-vinyl acetate copolymer, EVA, and acrylic copolymers are helpful modifications of polyvinylchloride that change its processing characteristics and elastomeric properties. Blending with these copolymers helps to reduce the requirement for low molecular weight plasticizers. Ethylene-vinyl acetate copolymer plays a role of high molecular weight plasticizer in production of vinyl hose. This reduces the amount of DOP used in flexible hose applications. Ethylene copolymer is used plasticize PVC that reduces gel. "" Phthalate plasticizers can be eliminated from water based adhesives because of utilization of vinyl acetate ethylene copolymer as a high molecular plasticizer/modifier. " ... 

Butadiene byu-to- dI- en, - dI-K [ISV butane - - dir -h -ene] (1900) N. Buta-1,3-diene, 1,3-butadiene, erythrene, vinylethylene, bivinyl, divinyl. CH2=CHCH=CH2. A gas, insoluble in water but soluble in alcohol and ether, obtained from cracking of petroleum, from coal-tar benzene, or from acetylene. It is widely used in the formation of copolymers with styrene, acrylonitrile, vinyl chloride and other monomers, imparting flexibility to the products made from them. Its homopolymer is a synthetic rubber. As noted it is a synthetic chemical compound, used principally in the... 

The vinylidene fluoride(VDF)-hexafluoropropylene(HFP) copolymers are well-known fluorocarbon elastomers which have excellent thermal, oil and chemical stability. Due to their inert structure, curing is more difficult compared with the hydrocarbon elastomers such as styrene-butadiene copolymer, acrylonitrile-butadiene copolymer etc. It is known that two curing recipes described below are practically usable for these fluorocarbon elastomers. 

The principal uses of acrylonitrile are in Acrylic fibers, copolymers with styrene (SAN), and in combination with butadiene and styrene (ABS). (see Acrylonitrile-Butadiene-Styrene). SAN copolymers are discussed in detail in later sections of this article. Following are a few other copolymers and their properties. 

Thus, performing the activation in the presence of radically polymerizable alkenes leads to the first examples of well-defined AB or ABA-type PVDF-block copolymers with styrene (e, e ), butadiene (f, f, vinyl chloride (g, g ), vinyl acetate (h, h ), methyl acrylate (i, i, i"). and acrylonitrile (j, j ), initiated from both the PVDF halide chain ends. While here Mn2(CO)io simply performs irreversible halide activation, and there is no IDT, control of the block copolymerization can be envisioned by other CRP methods. 

For the purposes of this chapter, acrylic polymers are defined as polymers based on acrylic acid and its homologues and their derivatives. The principal commercial polymers in this class are based on acrylic acid itself (I) and methacrylic acid (II) esters of acrylic acid (III) and of methacrylic acid (IV) acrylonitrile (V) acrylamide (VI) and copolymers of these compounds. Copolymers of methacrylic acid and ethylene are described in Chapter 2. The important styrene-acrylonitrile and acrylonitrile-butadiene-styrene copolymers are discussed in Chapter 3 whilst acrylonitrile-butadiene copolymers are dealt with in Chapter 18. 

Polyacrylonitrile (PAN) is formed by the peroxide-initiated free-radical polymerization of acrylonitrile (CH2=CH—CN). The major application of PAN is as the fiber Orion. When copolymerized with butadiene, it forms Buna N or nitrile rubber, which is resistant to hydrocarbons and oils. As a copolymer with styrene (SAN), it is a transparent plastic with very good impact strength used for machine components and for molding crockery. As a terpolymer of acrylonitrile-butadiene-styrene (ABS), the plastic is known for its toughness and good strength and finds applications in water lines and drains. 

Curatives are introduced into compounds to crosslink polymer chains. The most important curative is sulfur which produces (polymer)-S -(polymer) crosslinks. This primarily involves unsaturated elastomers based on isoprene and butadiene such as natural rubber, polybutadiene, and its copolymers with styrene and acrylonitrile (see Section 1.3). After crosslinking, the polymer networks show increased retractive force and reduced creep. The cured rubber becomes insoluble and it cannot be processed in the molten state. The concentration of curatives and their reactivity affect the degree of crosshnking. 

A new and efficient mode of operation is presented that involves a continuous rapid-scan FTIR spectrometer, the measurement technique relying completely on the utilisation of the digital signal processor for data acquisition and manipulation. Experimental and mathematical details were discussed. Application of the rapid-scan technique was illustrated with some results for a styrene-acrylonitrile/butadiene copolymer. 17 refs. 

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