Acrylonitrile—Butadiene —Styrene ABS

ABS structural foam has excellent buoyancy, a very low (desirable) stiffness-to-weight ratio, good screw and staple pull-out strengths, and creep resistance superior to that of high-impact polystyrene (HIPS) and polyethylene foams. This is particularly important in load-bearing applications, such as pellets, tote boxes, fumitine, and parts buried under earth loads (6). 

ABS polymers are derived from acrylonitrile, butadiene, and styrene and have the following general chemical structure  

The properties of ABS pol)rmers can be altered by the relative amounts of acrylonitrile, butadiene, and st3rrene present. Higher strength,better toughness, greater dimensional stability and other properties can be obtained at 

Pure ABS polymers will be attacked by oxidizing agents and strong acids, and they will stress crack in the presence of certain organic compounds. It is resistant to aliphatic hydrocarbons, but not to aromatic or chlorinated 

ABS will be degraded by UV light unless protective additives are incorporated into the formulation. 

When an ABS alloy or a reinforced ABS is used, all of the alloying ingredients and/or reinforcing materials must be checked for chemical compatibility. The manufacturer should also be checked. Table 2.10 provides the compatibility of ABS with selected corrodents. A more detailed listing may be found in Reference [1]. 

ABS is claimed to be the engineering resin most used when measured in terms of sales volume. Mainly used in the automotive industry, its second largest user sector is the electronics sector where it is a popular choice, especially for the production of intricate parts. ABS has good dimensional stability at both high and low temperatures and ABS may be coated with metallic surfaces, for example nickel. Its UL 94 [3] flammability classification is from HB to VO. Many manufacturers, who offer different grades according to the end use, include BASF (Terluran), Dow (Magnum) and Polimeri Europa (Sinkral). 

The impact properties of ABS are exceptionally good at room temperature and, with special grades, at temperatures to as low as -40°C (-40°F). Because of its plastic yield at high strain rates, impact failures in ABS are ductile rather than brittle. Also, the skin effect that in most other thermoplastics accounts for a lower impact resistance in thick sections than in thin ones is not pronounced in ABS. A long-term tensile-design stress of 6,900 to 10,340 kPa (1,000 to 1,500 psi) at 23°C (73°F) is recommended for most grades. 

Resin Trade Name Manufacturer HOT op2 Major Property Advantages Applications 

Polyphenylene Ryton Phillips 66 500 (260T) 425 (218°C) Heat resistance, good Automotive, electrical. 

Polyamideimide AT-no Amoco 525 (274) 450 (232) Superior mechanical Aerospace motor parts. 

Polyetherether- Victrex 430 (221) Outstanding thermals. Wire and cable 

Bodied solvent cements are usually used to bond ABS. Adhesives recommended include epoxies, urethanes, second-generation acrylics, vinyls, nitrile-phenolics, and cyanoacrylates.  

These plastics (cellulose acetate, cellulose acetate butyrate (CAB), cellulose nitrate, cellulose propionate, and ethyl cellulose) are ordinarily solvent cemented, but for bonding to non-solvent-cementable materials, conventional adhesives must be used. Adhesives commonly used are polyurethanes, epoxies, and cyanoacrylates. Cellulosic plastics may contain plasticizers that are not compatible with the adhesive selected. The extent of plasticizer migration should be determined before an adhesive is selected. Recommendations for conventional adhesives for specific cellulosic types are as follows  

Acrylonitrile-butadiene-styrene (ABS), an amorphous pol5nner, has been in mass production since the 1960s. It is a st5Tenic copolymer blend made out of elastomeric components and an amorphous thermoplastic component. The elastomeric component is usually polybutadiene or a butadiene copolymer. The thermoplastic component is SAN, a copolymer of styrene and acrylonitrile. SAN 

The main disadvantages of ABS are its poor solvent and fatigue resistance, poor UV resistance, unless protected, and maximum continuous use temperature is only around 70 °C. 

ABS compounds are available in many forms including medium and high impact grades, high gloss, UV stabilized, flame retardant, heat resistant, low gloss, glass-fibre reinforced and transparent. 

Elastic modulus (MPa) (tensile with 0.2% water content) 1380-3105 966-2070 690-8280 

Impact ABS is used for helmets, pipes and fittings, and housings for items such as vacuum cleaners, telephone sets and cameras. High gloss grades are used for domestic appliances such as 

In contrast to SAN, it is not transparent and needs stabilization for external exposure. The price of ABS is about 1.5 times that of PS, and it suffers strong competition from PP, which is also much cheaper. However, ABS is considered more engineering-like. Its range of utility is wide—pipelines for 

This is a terpolymer the first monomer is butadiene the second, acrylonitrile, consists of an ethylene molecule in which a hydrogen atom is replaced by a nitrile group (i.e., CN) and the third is styrene (i.e., an ethylene molecule with a phenyl group replacing a hydrogen atom). 

The first mechanical blends of NBR with SAN, known as type-A ABS, date from 1936. In the mid-1940s, Dow started emulsion polymerization of ABS-type G. By the late 1950s, the high heat ABS were invented, viz., interpolymers of a-methylstyrene and acrylonitrile (Irving 1961), a mixture of methylmethaciylate-a-methylstyrene either with styrene-grafted polybutadiene (SBR) or with an ABS (Kanegafuchi 1%7,1984), a mixture of SMA and ABS (Stafford and Adams 1972), a mixture of SMA with ABS and MBS (Tatuhiko and Akira 1982), a mixture of SMA-MMA with ABS, etc. 

Acrylonitrile-styrene-acrylate terpolymers, known as either ASA or AAS, constitute another class of ABS resins, viz., Centrex , Luran S, Richform , etc. These materials may also contain reactive groups, viz., maleic anhydride or glycidyl methacrylate. 

There are several reasons for blending PVC with ABS-type copolymers, viz., to 

There are many similarities between ABS/PVC and ABS/PC blends. Both are immiscible, having three distinct phases of PVC or PC, SAN, and an elastomer 

weatherability, thermal, and mechanical performance EVAc Hasegawa et al. 1974 

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Acrylonitrile-butadiene-styrene (ABS) copolymer Poly(vinylidene chloride)... 

In the case of poly(vinyl chloride) plastics, the FWA is mixed dry with the PVC powder before processing or dissolved in the plasticising agent (see Vinyl polymers). Polystyrene, acrylonitrile—butadiene—styrene (ABS), and polyolefin granulates are powdered with FWA prior to extmsion (2,78) (see... 

Over 70% of the total volume of thermoplastics is accounted for by the commodity resins polyethylene, polypropylene, polystyrene, and poly(vinyl chloride) (PVC) (1) (see Olefin polymers Styrene plastics Vinyl polymers). They are made in a variety of grades and because of their low cost are the first choice for a variety of appHcations. Next in performance and in cost are acryhcs, ceUulosics, and acrylonitrile—butadiene—styrene (ABS) terpolymers (see... 

Automotive appHcations account for about 116,000 t of woddwide consumption aimuaHy, with appHcations for various components including headlamp assembHes, interior instmment panels, bumpers, etc. Many automotive appHcations use blends of polycarbonate with acrylonitrile—butadiene—styrene (ABS) or with poly(butylene terephthalate) (PBT) (see Acrylonitrile polymers). Both large and smaH appHances also account for large markets for polycarbonate. Consumption is about 54,000 t aimuaHy. Polycarbonate is attractive to use in light appHances, including houseware items and power tools, because of its heat resistance and good electrical properties, combined with superior impact resistance. 

Acrylonitrile—Butadiene—Styrene. ABS is an important commercial polymer, with numerous apphcations. In the late 1950s, ABS was produced by emulsion grafting of styrene-acrylonitrile copolymers onto polybutadiene latex particles. This method continues to be the basis for a considerable volume of ABS manufacture. More recently, ABS has also been produced by continuous mass and mass-suspension processes (237). The various products may be mechanically blended for optimizing properties and cost. Brittle SAN, toughened by SAN-grafted ethylene—propylene and acrylate mbbets, is used in outdoor apphcations. Flame retardancy of ABS is improved by chlorinated PE and other flame-retarding additives (237). 

Two commercially significant graft copolymers are acrylonitrile—butadiene—styrene (ABS) resins and impact polystyrene (IPS) plastics. Both of these families of materials were once simple mechanical polymer blends, but today such compositions are generally graft copolymers or blends of graft copolymers and homopolymers. 

As of 1992, the first specialty platable plastic, acrylonitrile—butadiene—styrene (ABS) terpolymer (see Acrylonitrile polymers, ABS resins), is used ia over 90% of POP appHcatioas. Other platable plastics iaclude poly(pheayleae ether) (see PoLYETPiERs), ayloa (see Polyamides), polysulfoae (see Polymers CONTAINING sulfur), polypropyleae, polycarboaate, pheaoHcs (see Pphenolic resins), polycarboaate—ABS alloys, polyesters (qv), foamed polystyreae (see Styrene plastics), and other foamed plastics (qv). 

Worldwide sales of poly(phenylene ether)—styrene resin alloys are 100,000—160,000 t/yr (47,96) aimual growth rates are ca 9%. Other resin, particularly acrylonitrile—butadiene—styrene (ABS) polymers and blends of these resins with PC resins, compete for similar appHcations. 

The important thermoplastics used commercially are polyethylene, acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), cellulose acetate butyrate (CAB), vinylidene chloride (Saran), fluorocarbons (Teflon, Halar, Kel-F, Kynar), polycarbonates, polypropylene, nylons, and acetals (Delrin). Important thermosetting plasttcs are... 

Acrylonitrile butadiene styrene (ABS) polymers have good resistance to nonoxidizing and weak acids but are not satisfac tory with oxidizing acids. The upper temperature limit is about 65°C (150°F). 

At one time butadiene-acrylonitrile copolymers (nitrile rubbers) were the most important impact modifiers. Today they have been largely replaced by acrylonitrile-butadiene-styrene (ABS) graft terpolymers, methacrylate-buta-diene-styrene (MBS) terpolymers, chlorinated polyethylene, EVA-PVC graft polymers and some poly acrylates. 

The homopolymers, which are formed from alkyl cyanoacrylate monomers, are inherently brittle. For applications which require a toughened adhesive, rubbers or elastomers can be added to improve toughness, without a substantial loss of adhesion. The rubbers and elastomers which have been used for toughening, include ethylene/acrylate copolymers, acrylonitrile/butadiene/styrene (ABS) copolymers, and methacrylate/butadiene/styrene (MBS) copolymers. In general, the toughening agents are incorporated into the adhesive at 5-20 wt.% of the monomer. 

Acrylonitrile-butadiene-styrene (ABS). ABS materials have superior strength, stiffness and toughness properties to many plastics and so they are often considered in the category of engineering plastics. They compare favourably with nylon and acetal in many applications and are generally less expensive. However, they are susceptible to chemical attack by chlorinated solvents, esters, ketones, acids and alkalis. 

Figure 12.10 Microcolumn SEC-LC analysis of an acrylonitrile-butadiene-styrene (ABS) teipolymer sample (a) SEC ti ace (b) EC ti ace. SEC conditions fused-silica column (30 cm X 250 mm i.d.) packed with PL-GEL (50 A pore size, 5 mm particle diameter) eluent, THE at a flow rate of 2.0 mL/min injection size, 200 nL UV detection at 254 nm x represents the polymer additive fraction (6 p-L) tr ansferred to EC system. EC conditions NovaPak CIS Column (15 cm X 4.6 mm i.d.) eluent, acetonitrile-water (60 40) to (95 5) in 15 min gradient flow rate of 1.5 mL/min detection at 214 nm. Peaks identification is follows 1, styrene-acrylonitrile 2, styrene 3, benzylbutyl phthalate 4, nonylphenol isomers 5, Vanox 2246 6, Topanol 7, unknown 8, Tinuvin 328 9, Irganox 1076 10, unknown. Reprinted with permission from Ref. (14).

Polymers are suspended as microparticles in the latex and interactions between these microparticles are prevented by the presence of adsorbed suspending agent and soap molecules. Blending results in a random suspension of dissimilar particles in the mixture of latexes, each unaffected by the other. Rate of flocculation depends entirely on the stabilizer and not on the polymer characteristics as such. Coagulated mass contains an intimate mixture of the polymers. Acrylonitrile butadiene styrene (ABS) polymers [23-25] may be prepared by this method. 

Boronic acids (69 and 70) (Fig. 45) with more than one boronic acid functionality are known to form a polymer system on thermolysis through the elimination of water.93 Specifically, they form a boroxine (a boron ring system) glass that could lead to high char formation on burning. Tour and co-workers have reported the synthesis of several aromatic boronic acids and the preparation of their blends with acrylonitrile-butadiene-styrene (ABS) and polycarbonate (PC) resins. When the materials were tested for bum resistance using the UL-94 flame test, the bum times for the ABS samples were found to exceed 5 minutes, thereby showing unusual resistance to consumption by fire.94... 

Engineering polymers are often used as a replacement for wood and metals. Examples include polyamides (PA), often called nylons, polyesters (saturated and unsaturated), aromatic polycarbonates (PCs), polyoxymethylenes (POMs), polyacrylates, polyphenylene oxide (PPO), styrene copolymers, e.g., styrene/ acrylonitrile (SAN) and acrylonitrile/butadiene/styrene (ABS). Many of these polymers are produced as copolymers or used as blends and are each manufactured worldwide on the 1 million tonne scale. 

There are various requirements for impact-modified PVC. The most demanding is for outdoor sidings and window frames, where lifetimes of 20 years are expected. Because butadiene polymers or copolymers (e.g., acrylonitrile/butadiene/styrene (ABS), methyl methacrylate/butadiene/styrene (MBS)) are susceptible to UV degradation these polymers are usually not employed instead acrylate polymers are used for these applications. 

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