Styrene-butadiene-acrylonitrile

Acrylonitrile-butadiene-styrene (ABS) is one of the most frequently used polymers in the production of electrical and electronic equipment, it also has widespread applications in automobiles, communication instruments and other commodities. Within the electrical and electronic sector, the quantity of recycled plastics could be increased via the recycling of ABS to reduce environmental, economic and energy issues. Table 2.5 illustrates some of the physical parameters of ABS. 

ABS is sensitive to oxidation due to the presence of polybutadiene components, which act as oxidation sensitisers and lead to the formation of carbonyl groups, which absorb at 1,680-1,750 cm [29]. 

ABS consists of a styrene/acrylonitrile continuous phase partially grafted to a dispersed butadiene phase. Butadiene acts as an impact modifier, and imparts excellent mechanical properties to the material. Improvement of the impact-modifying properties of ABS during melt processing and product use focuses on protecting the poly butadiene phase from degradation. Polybutadiene is particularly susceptible to oxidation due to the presence of residual double bonds [37]. The properties of ABS are tabulated in Table 2.7. 

After periods of exposure to heat and oxygen, the mechanical properties of ABS, including impact strength and elongation to break, deteriorate as a consequence of this polymer degradation, inducing premature failure [38]. 

Tg rubber phase °C (from styrene butadiene rubber) -55 [39] 

Several types of plasticizers are used in ABS. These include hydrocarbon processing oil, phosphate esters (e.g., triphenyl phosphate, resorcinol bis(diphenyl phosphate), or oligomeric phosphate), long chain fatly acid esters, and aromatic sttlforramide.  

Aromatic sulforramide plasticizer is designed to produce non-fogging parts for automotive industry from ABS, its blends, and other polymers. 

No studies are thus far available that propose the mechanisin of action of plasticizers in any of the functions listed in Section 11.1.3. 

Melt flow rate depends on the type and the concentration of plasticizer selected. Resorcinol bis(diphenyl phosphate) at a concentration of 4 wt% almost doubled the melt flow rate being substantially more effective than triphenyl phosphate. Mineral oil did not affect the melt flow when added at 2 wt% but reduced it when the concentration was doubled. This, and the effects on mechanical properties, indicate that phosphate compounds interact with polymer chains (as typical of plasticizers) whereas mineral oil acts as an external lubricating oil that is incompatible with the polymer. 

Even small amounts of phosphate plasticizers improve flame retarding properties bnt at least 8 phr are needed to meet typical flame resistance requirements. The concentration may be varied depending on the formulation, which may include other flame retarding components. 

respectively, according to the Arrhenius relationship. From the slope of these plots, the activation energies corresponding to the glass transition were roughly estimated as AH = 105 and 298 kJ/mol for PBD and SAN, respectively. 

With these limited experimental data, it can be nevertheless seen that the activation energy of the brittle-ductile transition is significantly lower than that of the glass transition of PBD and SAN. It is important to point out that the fundamental difference between DMTA and fracture tests is that DMTA only 

Turner, C.E. (1980) in Fracture Mechanics Twelfth Conference (ASTM STP 700), American Society for Testing and Materials, Philadelphia, PA, pp. 314-337. 

Vu-Khanh, T. and Fisa, B. (1990) Theor. Appl. Fract. Mech. 13, 11. 

(1973) Handbook of Stress Intensity Factors, Lehigh University, Bethlehem, PA. 

ABS with core-shell particles in different thick specimens in the TEM  

very small, partly agglomerated rubber particles (dark)  

---

Acrylonitrile-butadiene-styrene-poly(vinyl chlo- Nitrile resins... 

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

Polycarbonate acrylonitrile-butadiene-styrene alloy Allyl-diglycol- carbonate polymer Diallyl phthalate molding Cellulose acetate Cellulose-acetate-butyrate resin... 

Analytical investigations may be undertaken to identify the presence of an ABS polymer, characterize the polymer, or identify nonpolymeric ingredients. Fourier transform infrared (ftir) spectroscopy is the method of choice to identify the presence of an ABS polymer and determine the acrylonitrile—butadiene—styrene ratio of the composite polymer (89,90). Confirmation of the presence of mbber domains is achieved by electron microscopy. Comparison with available physical property data serves to increase confidence in the identification or indicate the presence of unexpected stmctural features. Identification of ABS via pyrolysis gas chromatography (91) and dsc ((92) has also been reported. 

Acrylonitrile—Butadiene—Styrene. Available only as sheet, ABS has good toughness and high impact resistance. It is readily therm oform able over a wide range of temperatures and can be deeply drawn. ABS has poor solvent resistance and low continuous-use temperature. It is often used in housings for office equipment (see Acrylonitrile polymers). 

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). 

Fig. 10. Preparation and morphology of toughened PVC (a) secondary PVC grain (50—250 flm) (b) modified PVC with coherent primary grain (ca 1 -lm) (220). CPE = chlorinated polyethylene EVA = ethylene—vinyl acetate copolymers ABS = acrylonitrile—butadiene—styrene MBS = methyl...

Styrene [100-42-5] (phenylethene, viaylben2ene, phenylethylene, styrol, cinnamene), CgH5CH=CH2, is the simplest and by far the most important member of a series of aromatic monomers. Also known commercially as styrene monomer (SM), styrene is produced in large quantities for polymerization. It is a versatile monomer extensively used for the manufacture of plastics, including crystalline polystyrene, mbber-modifted impact polystyrene, expandable polystyrene, acrylonitrile—butadiene—styrene copolymer (ABS), styrene—acrylonitrile resins (SAN), styrene—butadiene latex, styrene—butadiene mbber (qv) (SBR), and unsaturated polyester resins (see Acrylonithile polya rs Styrene plastics). 

Acrylonitrile—Butadiene—Styrene Copolymer (ABS). Uses for ABS are in sewer pipes, vehicle parts, appHance parts, business machine casings, sports goods, luggage, and toys. 

Property Polystyrene (PS) Poly(styrene-i) (j-acrjio-nitrile ) (SAN) Glass-fil led PS High impact PS HIPS Acrylonitrile— butadiene—styrene terpolymer (ABS) Type 1 Type 2 Standard ABS Super ABS... 

Rubber-Modified Copolymers. Acrylonitrile—butadiene—styrene polymers have become important commercial products since the mid-1950s. The development and properties of ABS polymers have been discussed in detail (76) (see Acrylonitrile polymers). ABS polymers, like HIPS, are two-phase systems in which the elastomer component is dispersed in the rigid SAN copolymer matrix. The electron photomicrographs in Figure 6 show the difference in morphology of mass vs emulsion ABS polymers. The differences in stmcture of the dispersed phases are primarily a result of differences in production processes, types of mbber used, and variation in mbber concentrations. 

MBS = methyl methacrylate—butadiene—styrene and MABS = methacrylate-acrylonitrile—butadiene—styrene. 

ABS (acrylonitrile—butadiene-styrene) resins are two-phase blends. These are prepared by emulsion polymerization or suspension grafting polymerization. Products from the former process contain 20—22% butadiene those from the latter, 12—16%. 

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). 

---