Styrene —Acrylonitrile SAN

SAN is a copolymer of styrene and acrylonitrile having the following chemical stmcture  

SAN is resistant to aliphatic hydrocarbons, not to aromatic and chlorinated hydrocarbons. It will be attacked by oxidizing agents and strong acids, and it will stress crack in the presence of certain organic compounds. 

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

SAN finds application as food and beverage containers, dinnerware, housewares, appliances, interior refrigerator components, and toys. Industrial applications include fan blades and filter housings. Medical applications include tubing connectors and valves, labware, and urine bottles. The packaging industry makes use of SAN for cosmetic containers and displays. 

The copolymer SAN (Ty ril —Dow Chemical Co.) is usually solvent cemented with solvents similar to those used for PS, although effective solvents are more limited. In applications where solvent cements cannot be used, as in bonding to metals, the procedures suggested for PS may be used. TCE and gasoline have also been used, with no further treatment.  

The techniques used for solvent cementing polystyrene are applicable to SAN, but the list of solvents is more restricted. Solvent cements recommended are given in Table 9.8. 

Solutions of approximately 5% SAN in methyl ethyl ketone may be used effectively as bodied cements.  

Solvent cementing of polysulfone can be carried out with chlorinated hydrocarbons. A solution of 5% polysulfone resin in methylene chloride can be used to bond polysulfone to itself. High pressures (3.45 MPa) for 5 minutes are required. A minimum amount of solvent should be applied to the mating surfaces. The strength of a properly prepared joint will exceed the strength of the polysulfone parts. Polysulfone can be solvent-cemented to other plastics using a solvent compatible with both plastics.  

This material is similar in its flow behavior to PMMA and is therefore relatively stiff flowing. 

Saturated hydrocarbons, low aromatic engine fuels and oils, vegetable fats and oils, animal fats and oils, aqueous solutions of salts and, dilute acids and alkalis. 

Aromatic and chlorinated hydrocarbons esters, ethers, ketones and various chlorinated hydrocarbons,for example, methylene chloride, ethylene chloride and trichloroethylene also attacked by concentrated inorganic acids. Environmental stress cracking may be assessed by immersion in a mixture of olive oil and oleic acid. 

A common feature of all styrene plastics is their resistance to an aqueous media such as salt solutions, acids of medium concentration and alkalis. Aliphatic hydrocarbons, for example, heptane and cyclohexane, readily attack PS and TPS but do not affect SAN and ABS. Carbon tetrachloride (CCI4) attacks SAN and ABS only slowly but quickly attacks PS and TPS. Resistance to CCI4 may be used to distinguish between PS and SAN. In the case of the polystyrene, when it is immersed in the CCI4 it immediately becomes sticky whilst SAN is relatively unaffected. Alternatively if a few drops of CCI4 are put into a test tube containing PS or SAN. In the case of the PS, the liquid becomes milky in a short period of time whereas with SAN it remains colorless. 

Work handling devices are being increasingly used for the 

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Styrene-acrylonitrile (SAN) copolymer Poly(vinyl butyrate) (PVB)... 

Styrene-Acrylonitrile (SAN) Copolymers. SAN resins are random, amorphous copolymers whose properties vary with molecular weight and copolymer composition. An increase in molecular weight or in acrylonitrile content generally enhances the physical properties of the copolymer but at some loss in ease of processing and with a slight increase in polymer color. 

Styrene—acrylonitrile (SAN) copolymers [9003-54-7] have superior properties to polystyrene in the areas of toughness, rigidity, and chemical and thermal resistance (2), and, consequendy, many commercial appHcations for them have developed. These optically clear materials containing between 15 and 35% AN can be readily processed by extmsion and injection mol ding, but they lack real impact resistance. 

Coran and Patel [33] selected a series of TPEs based on different rubbers and thermoplastics. Three types of rubbers EPDM, ethylene vinyl acetate (EVA), and nitrile (NBR) were selected and the plastics include PP, PS, styrene acrylonitrile (SAN), and PA. It was shown that the ultimate mechanical properties such as stress at break, elongation, and the elastic recovery of these dynamically cured blends increased with the similarity of the rubber and plastic in respect to the critical surface tension for wetting and with the crystallinity of the plastic phase. Critical chain length of the rubber molecule, crystallinity of the hard phase (plastic), and the surface energy are a few of the parameters used in the analysis. Better results are obtained with a crystalline plastic material when the entanglement molecular length of the... 

Copolymers of styrene-acrylonitrile (SAN) have higher tensile strength than styrene homopolymers. A copolymer of acrylonitrile, buta-... 

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. 

The primary use of acrylonitrile is as the raw material for the manufacture of acrylic and modacrylic fibers. Other Major uses include the production of plastics (acrylonitrile-butadiene- styrene (ABS) and styrene-acrylonitrile (SAN), nitrile rubbers, nitrile barrier resins, adiponitrile and acrylamide (EPA 1984). 

Styrene-acrylonitrile (SAN) copolymers have a high natural affinity for PBT, giving blends with good mechanical properties. If the SAN copolymer is grafted... 

ABS is often an alloy of styrene acrylonitrile (SAN) and polybutadiene rubber but sometimes it is a copolymer. 

Styrene acrylonitrile (SAN), acrylate rubber modified styrene acrylonitrile (ASA), acrylonitrile EPDM styrene (AES or AEPDS), acrylonitrile chlorinated polyethylene styrene (ACS)... 

ISO 4894-1 1997 Plastics - Styrene/acrylonitrile (SAN) moulding and extrusion materials -Part 1 Designation system and basis for specifications ISO 4894-2 1995 Plastics - Styrene/acrylonitrile (SAN) moulding and extrusion materials -Part 2 Preparation of test specimens and determination of properties ISO 19220 2004 Plastics piping systems for soil and waste discharge (low and high temperature) inside buildings - Styrene copolymer blends (SAN PVC)... 

Uses. Plastics and synthetic rubber are the major uses for styrene. They account for the exponential growth from a few million pounds per year in 1938 to more than 8 billion pounds today. The numerous plastics include polystyrene, styrenated polyesters, acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile (SAN), and styrene-butadiene (SB). Styrene-butadiene rubber (SBR) was a landmark chemical achievement when it was comrner-cialized during World War II. The styrene derivatives are found everywhere—in food-grade film, coys, construction pipe, foam, boats, latex paints, tires, luggage, and furniture. 

Nitrile rubber has declined in importance, but has been replaced by styrene-acrylonitrile (SAN) copolymers and acrylonitrile-butadiene-styrene... 

Sytrene-butadiene (Buna-S) and styrene-acrylonitrile (SAN) (Buna-N) copolymer elastomers Melamine-formaldehyde (ME) resins Nylon-6 (Schlack)... 

The most important commercial processes for polyacrylonitrile (XLIII) are solution and suspension polymerizations. Almost all the products containing acrylonitrile are copolymers. Styrene-acrylonitrile (SAN) copolymers are useful as plastics (Sec. 6-8a). 

Radical copolymerization of styrene with lCM-0% acrylonitrile yields styrene-acrylonitrile (SAN) polymers. Acrylonitrile, by increasing the intermolecular forces, imparts solvent resistance, improved tensile strength, and raises the upper use temperature of polystyrene although impact resistance is only slightly improved. SAN finds applications in houseware... 

Figure 3.5 shows aTEM picture of the core/double shell latex particles incorporated into an styrene/acrylonitrile (SAN) copolymer matrix (thin cut through the particle-filled matrix).The particles are very homogeneous in size and can also be used to prepare ar-tifical opals. 

In this paper a generalized approach is presented to the derivation of H-H-S equations for multispecies polymers created by addition polymerization across single double bonds in the monomers. The special cases of copolymers and terpolymers are derived. This development is combined with experimental results to evaluate the numerical parameters in the equations for poly(styrene-acrylonitrile ) (SAN) in three separate solvents and for poly(styrene-maleic anhydride-methyl methacrylate) (S/HA/MM) in a single solvent. The three solvents in the case of SAN are dimethyl formamide (DMF), tetrahydrofuran (THF), and methyl ethyl ketone (MEK) and the solvent for S/HA/HH is HER. 

Figure 5.99 Relationship of glass fiber content with (a) tensile strength and (b) flexural modulus for styrene acrylonitrile (SAN) and polypropylene (PP). Reprinted, by permission, from G. Lubin, Handbook of Fiberglass and Advanced Plastics Composites, p. 130. Copyright 1969 by Van Nostrand Reinhold.

Worldwide consumption of acrylonitrile increased 52% between 1976 and 1988, from 2500 to 3800 thousand tonnes per year. The trend in consumption over this time period is shown in Table 2 for the principal uses of acrylonitrile acrylic fibre, acrylonitrile-butadiene-styrene (ABS) resins, adiponitrile, nitrile rubbers, elastomers and styrene-acrylonitrile (SAN) resins. Since the 1960s, acrylic fibres have remained the major outlet for acrylonitrile production in the United States and especially in Japan and the Far East. Acrylic fibres always contain a comonomer. Fibres containing 85 wt% or more acrylonitrile are usually referred to as acrylics and fibres containing 35-85 wt% acrylonitrile are called modacrylics . Acrylic fibres are used primarily for the manufacture of apparel, including sweaters, fleece wear and sportswear, and home furnishings, including carpets, upholstery and draperies (Langvardt, 1985 Brazdil, 1991). 

IDES Integrated Design Engineering Systems, Styrene acrylonitrile (SAN) resins, IDES Inc. 209 Grand Avenue Laramie, WY 82070 USA [electronic ] http //www.ides.com/generics/SAN/SAN products.htm, 2008. 

Styrene-acrylonitrile (SAN) resins possess many physical properties desired for thermoplastic applications. They are characteristically hard, rigid, and dimensionally stable with load bearing capabilities. They are also transparent, have high heat distortion temperatures, possess excellent gloss and chemical resistance, and adapt easily to conventional thermoplastic fabrication techniques. 

Step 3—In a separate step, styrene-acrylonitrile (SAN) resin is prepared by emulsion, suspension, or mass polymerization by free-radical techniques. The operation is carried out in stainless-steel reactors operated at about 75°C (167°F) and moderate pressure for about 7 hours. Tlie final chemical operation is the blending of the ABS graft phase with the SAN resin, plus adding various antioxidants, lubricants, stabilizers, and pigments. Final operations involve preparation of a slurry of fine resin particles (via chemical flocculation), filtering, and drying in a standard fluid-bed dryer at 121-132°C (250-270°F) inlet air temperature. 

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