Plastics, commercial

The most chemical-resistant plastic commercially available today is tetrafluoroethylene or TFE (Teflon). This thermoplastic is practically unaffected by all alkahes and acids except fluorine and chlorine gas at elevated temperatures and molten metals. It retains its properties up to 260°C (500°F). Chlorotrifluoroethylene or CTFE (Kel-F, Plaskon) also possesses excellent corrosion resistance to almost all acids and alkalies up to 180°C (350°F). A Teflon derivative has been developed from the copolymerization of tetrafluoroethylene and hexafluoropropylene. This resin, FEP, has similar properties to TFE except that it is not recommended for continuous exposures at temperatures above 200°C (400°F). Also, FEP can be extruded on conventional extrusion equipment, while TFE parts must be made by comphcated powder-metallurgy techniques. Another version is poly-vinylidene fluoride, or PVF2 (Kynar), which has excellent resistance to alkahes and acids to 150°C (300°F). It can be extruded. A more recent development is a copolymer of CTFE and ethylene (Halar). This material has excellent resistance to strong inorganic acids, bases, and salts up to 150°C. It also can be extruded. 

Polyethylene is the lowest-cost plastic commercially available. Mechanical properties are generally poor, particularly above 50°C (120°F), ana pipe must be hilly supported. Carbon-filled grades are resistant to sunlight and weathering. 

Methacrylic acid and its esters are useful vinyl monomers for producing polymethacrylate resins, which are thermosetting polymers. The extruded polymers are characterized by the transparency required for producing glass-like plastics commercially known as Plexiglas ... 

One of the most chemical-resistant plastics commercially available today is tetrafluoroethylene or TFE (Teflon). This thermoplastic is practically unaffected by all alkalies and acids except fluorine and chlorine gas at elevated temperatures and molten metals. It retains its properties up to 260°C. Chlorotrifluo-roethylene or CFE (Kel-F) also possesses excellent corrosion resistance to almost all acids and alkalies up to 175°C. FEP, a copolymer of tetrafluoroethylene and hexafluoropropylene, has similar properties to TFE except that it is... 

Highest molecular weight and most permanent monomeric phthalate plasticizer commercially available. Used for high temperature rated PVC insulation. Other end uses include traffic cones, automotive sealants, fabric coatings, fishing lures and shoe compounds. 

Polychlorinated biphenyls (PCBs) have a variety of industrial applications related to their high chemical and thermal stabilities, electrical resistance and low volatilities. Some of their uses are as dielectric fluids in capacitors and transformers, as lubricants and hydraulic fluids, as heat exchangers and fire retardants and as plasticizers. Commercial production began in the USA in 1929, but restrictions were imposed in the 1970s because of growing concerns about adverse biological effects, and the use of PCBs was banned in the USA in 1986. Some 37 kt were produced in 1970 (Goldberg 1976), and total production to 1980 has been estimated at 1.2 Mt, of which c.65% is still in use or has been deposited in landfills, c.4% has been destroyed and c.31% has been released to the environment (Tanabe 1988). 

In the formulation of PVC compounds it is not uncommon to replace some of the plasticizer with an extender, a material that is not in itself a plasticizer because of its very low compatibility but that can be used in conjunction with a true plasticizer. Commercial extenders are cheaper than plasticizers and can often be used to replace up to one-third of the plasticizer without seriously affecting the properties of the compound. Three commonly employed types of extenders are chlorinated paraffin waxes, chlorinated liquid paraffinic fractions, and oil extracts [14]. 

The general physical properties of 1, 2-PBD film are shown in Table 1 compared with film properties of other soft plastics commercially available. The datas show that 1, 2-PBD film is comparable to LDPE, EVA and plastisized PVC in some physical strength. The characteristic points of 1, 2-PBD film may be summarized as follows ... 

Markets for plastics Commercial production of plastics Physical properties of plastics Fabrication of plastics Applications... 

Styrene-hydrogenated butadiene-styrene styrene-ethylene-buta-diene-styrene) terpolymers offer a further level of sophistication in terms of bulk compounds added to engineering plastics. Commercially available functionalized versions of these can be used either pure or in combination with their precursors for effective toughening of several engineering resins. 

Polyepoxide plasticizers are specially used for PVC, for chlorinated rubber, and in nitrocellulose varnishes. Ethylene-vinyl acetate copolymers (EVA) (vinyl acetate content of 65-70% by weight) are also of industrial interest as high-molecular-weight plasticizers for PVC, mainly because of their low cost [46]. A polymeric plasticizer commercially available from du Pont (PB-3041) allows the... 

Terephthalate esters are not as compatible as phthalates with PVC and are more difficult to process. Today there is essentially only one important terephthalate plasticizer commercially available, DEHTP, as terephthalate esters of C9 and CIO alcohols have compatibility issues. The diisoheptyl terephthalate ester was shown [27] to have advantages in processabihty and plasticizing efficiency over DEHTP, but with hmited availability of isoheptanol, this product was never commercialized. The terephthalate ester based on C4 alcohols, dibutyl terephthalate (DBTP) is now commercially available for use in plasticizer blends to help improve processability [28] of DEHTP. Although DEHTP is very similar to the structure of DEHP, the structural difference yields important effects in the plasticizer toxicity profile. Extensive testing of DEHTP confirms that it is a safer product than DEHP [24]. 

Solvents or detergent solutions can be used to remove mold-release agents or waxes from plastics. Commercial detergents such as Sprex (DuBois Chemical Co., 1120 West Front, Cincinnati, Ohio) are suitable. Acetone and methyl alcohol are effective solvents, depending on the type of plastic to be cleaned. The adverse effect of solvents on some polymeric materials should be checked before their use. 

Plasticizers commercially available 15-25 9 Resistant little or no change in weight small effect on mechanical properties generally suitable for practical use ... 

Bio-based plastics "Commercial or industrial goods, (other than feed or food), composed in whole or in significant part of biological products, forestry material, or renewable domestic agricultural materials, including plant, animal or marine materials" as defined by the US Department of Agriculture (USDA, 2005). 

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