Acrylonitrile butadiene styrene structure

An example of this type of a safer chemical is methacrylonitrile (1) compared with acrylonitrile (2) (Figure 1.1). Both compounds are a, 3-unsaturated aliphatic nitriles, and structurally very similar, but 2 causes cancer whereas 1 does not appear to do so. Among other applications, 2 is used in the production of acrylic and modacrylic fibers, elastomers, acrylonitrile-butadiene-styrene and styrene-acrylonitrile resins, nitrile rubbers, and gas barrier resins. In a study conducted by the US National Toxicology Program (NTP) in which 2 was administered orally to mice for 2 years, there was clear evidence that it caused cancer in the treated mice (in addition to causing other toxic effects), and is classified by the NTP as a probable human carcinogen [26]. 

Analysts. Analytical investigations may be undertaken ro identify the presence of an ABS polymer, characterize the polymer, or identify nonpolymenc ingredients. Fourier transfrom infrared (fhr) 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. Confirmation of the presence of rubber domains is achieved by electron microscopy. Comparison with available physical properly data serves to increase confidence in the identification or indicate the presence of unexpected structural features. Phase-seperalion techniques can be used to provide detailed compositional analyses. 

Characteristic functions and the representative structures of plastics additives providing marketable and durable materials are included in this chapter. Types of additives for plastics used in contact with food are listed in Table 3-1. Similar additives as for PS are used for elastomer-modified plastics forming multilayer systems (blends) and used rather exceptionally in contact with food, such as high-impact polystyrene (HIPS) or acrylonitrile-butadiene-styrene polymer (ABS). Some of the additives, stabilizers in particular, are very reactive and are present in the plastic matrix in a chemically transformed form. 

In works [46-48] by method of EPR-tomography thermo- and photo-oxidation of poly(acrylonitrile-butadiene)styrene (ABS) copolymer were studied. This polymer is structurally and dynamically micro-heterogeneous, i.e. there are regions with high content of polybutadiene and regions with high content of polystyrene or polyacrylonitrile. In polymer... 

Acrylonitrile-butadiene-styrene (ABS) and acrylonitrile-styrene-acry- late (ASA) are rubber-toughened plastics based upon the styrene-acrylonitrile (SAN) copolymer matrix. The combination of the stiffness and toughness exhibited by these materials has made them increasingly attractive in engineering applications, and the activity of the patent literature testifies to a continuing interest in improving properties through modifications of structure. The aim of this paper is to discuss a quantitative approach to structure-property relationships in ABS and ASA polymers. 

The uses of mercaptans in polymers fall into three major categories chain transfer agents, additives such as stabilizers against heat or UV light, and monomers that incorporate an alkylmercapto group into their structure. Mercaptans r-dodecyl, n-dododecyl, etc. are excellent chain transfer agents used to control molecular weight of several different kinds of polymers, styrene butadiene rubber, acrylonitrile-butadiene-styrene, polyacrylates, to name a few. " " ... 

The microphase structure and mechanical properties of the blends containing neat acrylonitrile-butadiene-styrene copolymer (ABS), styrene-acrylonitrile copolymer (SAN) and sodium sulfonated SAN ionomer have been investigated as a function of ion content of the ionomer in the blend by Park et a/.51 The interfacial adhesion was quantified by H NMR solid echo experiments. The amount of interphase for the blend containing the SAN ionomer with low ion content (3.1 mol%) was nearly the same as that of ABS, but it decreases with the ion content of the ionomer for the blend with an ion content greater than 3.1 mol%. Changing the ionomer content in the blends shows a positive deviation from the rule of mixtures in tensile properties of the blends containing the SAN ionomer with low ion content. This seems to result from the enhanced tensile properties of the SAN ionomer, interfacial adhesion between the rubber and matrix, and the stress concentration effect of the secondary particles. 

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 structure of the dispersed phases are primarily a result of differences in production processes, types of mbber used, and variation in mbber concentrations. 

Brominated flame retardants (BFRs) are a structurally diverse group of compounds including aromatics, cyclic aliphatics, phenolic derivatives, ahphatics, and phthahc anhydride derivatives (Figure 31.3). The most common BFRs are tetrabromobisphenol A (TBBPA), polybrominated diphenyl ethers (PBDE), hexabromocyclododecane (HBCD), and polybrominated biphenyls (PBB). The primary use of TBBPA is as reactive additive in epoxy resin circuit boards, while decabromodiphenyloxide (DBDO) is primarily used in high impact polystyrene for electronic enclosures. PBDEs are typically used as the additive type of flame retardant in high impact polystyrene, acrylonitrile butadiene styrene, flexible polyurethane foam, textile coatings, wire and cable insulation and electrical connectors. 

This polymer can be prepared by the interfacial polycondensation of bisphenol A alkali salt dissolved in the water phase and phosgene (COQj) dissolved in methylene chloride. It can be used either as the pure polymer or in blends, particularly with acrylonitrile-butadiene-styrene (ABS) copolymers. The bisphenol A structure appears in other combinations, e.g., in a polysulfone copolymer (see Table 15.10) and in aromatic polyesters with phthalic acid moieties... 

In experiments on immiscible blends, as noted by Dlubek et al. [2002], it is to be anticipated that the PALS parameters h and T3 will depend on the volume fractions and compositions of the three phases, as well as the effect of any interaction between the blend components. Such interactions have been identified in the studies of Wastlund et al. [1998] and Dlubek et al. [1999]. Thus, as pointed out above, the decrease in T3 observed by Wastlund et al. [1998] in 50 50 SMA24/SANx blends when the acrylonitrile content of the SANx increases from x=22% to x=33%, is interpreted as being due to increased interaction between the maleic anhydride and acrylonitrile groups. On the other hand, Dlubek et al. [1999] studied blends of an acrylonitrile-butadiene-styrene (ABS) copolymer and polyamide-6 (PA-6). This blend may be assumed to be quite heterogeneous, consisting of a two-phase structure having PA-6 crystals embedded in an amorphous ABS matrix and elastomeric... 

Figure 10.8 General chemical structure of poly(acrylonitrile-butadiene-styrene) (polyABS).

Styrene-acrylonitrile copolymers are produced commercially for use as structural plastics. The typical acrylonitrile content in such resins is between 20-30%. These materials have better solvent and oil resistance than polystyrene and a higher softening point. In addition, they exhibit better resistance to cracking and crazing and an enhanced impact strength. Although the acrylonitrile copolymers have enhanced properties over polystyrene, they are still inadequate for many applications. Acrylonitrile-butadiene-styrene polymers, known as ABS resins, were therefore developed. 

Multi-block copolymers can form a greater variety of ordered phase structures than diblock copolymers, via self-assembly. Some of them have been widely applied as the matrix materials, such as styrene-butadiene-styrene (SBS) thermal elastomers, acrylonitrile-butadiene-styrene (ABS) copolymers and polyurethanes. 

The behavior of the two-phase systems is complex and responses on aging can be affected by the thermal history and aging temperature. This is well illustrated by a series of investigations, the two-phase blend of acrylonitrile-butadiene-styrene copolymer (ABS, Tg = 110 °C) and polycarbonate of bisphenol-A (BPAPC, Tg = 151 °C). Due to the phase-separated structure of the blend, two enthalpy recovery peaks are detected by enthalpy relaxation and attributed to the two components (Tang and Lee-SuUivan 2008). However, aging appears to have little effect on the ABS component even at temperatures close to the ABS glass transition. 

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