Soft drink bottles, polyester

Labels for soft drink bottles, shampoo bottles, plastic food containers and the like, require high adhesion to materials like polyester and polyolefins. Once applied, the adhesive may have to withstand repeated flexing, freezing, water and other fluid spillage, while maintaining aesthetic appearance. 

Problem 31.8 I Polyfethylene terephthalate), or PET, is a polyester used to make soft-drink bottles. 

A description is given of a comparative study of the glycolysis of PETP waste soft drinks bottles by various mixtures of EG and DEG with subsequent polyesterification of the glycolysed products by maleic anhydride in order to obtain unsaturated polyesters suitable for the production of varnishes. The processing characteristics such as viscosity, exotherm temperatures of curing, compatibility of resins with monomers was investigated with respect to the type and amount of reactive monomers. The mechanical properties of varnishes produced were analysed. 13 refs. 

Both terephthalic acid (TPA) and dimethyl terephthalate (DMT) are used exclusively for the manufacture of polyesters for textile fibers (e.g,. Dacron ), films, soft-drink bottles, and engineering resins for automotive applications. The glycol used for most TPA-based polyesters is ethylene glycol. The polyester is then known as polyethylene terephthalate, or PET. 

Because the monomers above are all joined by ester linkages, the polymer chain is a polyester. This one is called PET, which stands for poly(ethylene terephthalate). (PET is used to make soft-drink bottles, magnetic tape, and many other plastic products.)... 

Esters are widely used in industry as solvents. Ethyl acetate is a good solvent for a wide variety of compounds, and its toxicity is low compared with other solvents. Ethyl acetate is also found in household products such as cleaners, polishes, glues, and spray finishes. Ethyl butyrate and butyl butyrate were once widely used as solvents for paints and finishes, including the butyrate dope that was sprayed on the fabric covering of aircraft wings to make them tight and stiff. Polyesters (covered later in this section and in Chapter 26) are among the most common polymers, used in fabrics (Dacron ), films (VCR tapes), and solid plastics (soft-drink bottles). 

Terephthalic acid (TPA), a raw material in the manufacture of polyester fiber, film, and soft drink bottles, is synthesized from p-xylene (PX) in the process shown below. 

All rubbers, glasses, and plastics are polymers. You are probably familiar with natural polymers like cellulose (the building block of plant fibers) and synthetic polymers like polyethylene (plastic milk cartons), polyisoprene (automobile tires), polyethylene terephthalate (soft drink bottles), polymethyl methacrylate (Plexiglas ), polyvinylidene chloride (transparent plastic wrap), polytetrafluoroethylene (Teflon ), and various polyesters (fabrics). Polyvinyl chloride, the polymer shown earlier, is used to make rigid pipes, house siding, and protective coverings for automobile seals and dashboards, among many other applications. 

Blow moulded soft drinks bottles are made without seams from polyester. 

This is a thermoplastic polymer resin of the polyester family and is usually referred to as polyester. PET can be semi-rigid to rigid depending on its thickness and is very lightweight, clear, strong and impact resistant, has good gas- and moisture-resistant barrier properties and is widely used for soft drink bottles. 

The process is used extensively for the production of yarns and fibres monofilaments and strapping for recycling of scrap polyesters in production of PET containers and soft-drink bottles engineering grades of PET and PBT for electrical, engineering and automotive applications. 

This is the polyester you find in clothing (boy, did I ever love that baby-blue leisure suit I had in the 70sf), artificial automotive tire cord, substitute blood vessels, film, and soft drink bottles. 

Polyethylene terephthalate (PET, polyethylene glycol terephthalate) n. A saturated, thermoplastic polyester resin made by condensing ethylene glycol, and terephthalic acid, used for textile fibers, water-clear, biaxially oriented film (e.g., Mylar ) and, more recently, for extruded, thermoform-able sheet (TV-dinner trays), injection-molded parts, and large, blow-molded, soft-drink bottles. It is extremely hard, wear- and chemical-resistant, dimensionally stable, and has good dielectric properties. See also polyester, saturated and crystallized polyethylene terephthalate (See image). 

Not aU polymers can crystallize. Polyethylene does, but atactic polystyrene (the common form) does not. Though the speciahzed syndiotactic and the more common isotactic forms do, albeit into completely different crystal forms (de Rosa and Auriemma 2013). Isotactic polypropylene and many nylons commonly crystallize into more than one crystal type, and polyethylene terephthalate (PET), a polyester, is commonly found in a glassy form in soft drinks bottles but crystallizes readily on appropriate thermal treatment. 

The linear polyester formed above is a polyethylene terephthalate, or PET. It has a molar mass of about 15,000 g/mol. Because the ester group is polar, attractions between polymer chains are of a dipole type and are fairly strong. As a result, PET polymers are used in fibers such as Fortrel and Dacron (Fig. 21.35). Longer PET polymers are used for tire cords. Made into a Mylar film and coated with magnetic particles, PET becomes the base for audio and video recording tape. Two-liter soft drink bottles are a PET polymer. 

Dacron is the most common of the group of step-growth polymers known as polyesters— polymers containing many ester groups. Polyesters are used for clothing and are responsible for the wrinkle-resistant behavior of many fabrics. Dacron is made by the transesterification of dimethyl terephthalate with ethylene glycol (Section 16.10). The durability and moisture resistance of this polymer contribute to its wash-and-wear characteristics. Because PET is lightweight, it is also used for transparent soft drink bottles. 

CI.43 The plastic known as PETE (polyethyleneterephthalate) is a polymer of terephthalic acid and ethylene glycol. PETE is used to make plastic soft drink bottles and containers for salad dressings, shampoos, and dishwashing liquids. Today, PETE is the most widely recycled of all the plastics in a single year, 2.4 X 10 lb of PETE are recycled. After PETE is separated fiom other plastics, it can be used in polyester fabric, fill for sleeping bags, door mats, and tennis ball containers. The density of PETE is 1.38 g/mL. (2.6, 2.7, 8.4,17.6)... 

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