Polyethylene terephthlate

INVENTA-FISCHER Polyethylene terephthlate (PET) Terephthalic acid, ethylene glycol 4-reactors continuous process produces amorphous PET chips or fibers and filaments capacities up to 600 tpd available 300 2000... 

Epcos offers epoxy resin sealed metallised polyester (polyethylene terephthlate) film types with the addition of a UL 94 VO plastic case. MetalUsed polypropylene types offered by Epcos are claimed to have very good self-healing properties and a very high pulse strength. 

Figure 12-7. Goodyear had this two-piece suit and matching tie made from recycled two-liter polyethylene terephthlate (PET) beverage bottles in 1978 and in 1990 donated it to the new Ripley s Believe It or Not Museum in Wisconsin Dells, Wise. The recycling process that Goodyear developed shreds bottles into small flakes that can then be processed into a reuseable TP polyester resin. Goodyear had the suit made to demonstrate the versatility of its recycled PET.

The best approach to determining the answer to the problem is to examine reference spectra of para-substituted aromatic-ester-type polymers such as alkyds or polyesters. When this is done, the answer is found to be polyethylene terephthlate. 

Ester groups occur in a wide range of polymers, e.g., polyethylene terephthlate. The classic chemical method for the determination of ester groups, namely saponification, can be applied to some types of polymer. For example, copolymers of vinyl esters and esters of vinyl esters and esters of acrylic acid can be saponified in a sealed tube with 2 M sodium hydroxide. The free acids from the vinyl esters can then be determined by GC. The alcohols formed by the hydrolysis of the acrylate esters are determined by GC. Polymethyl acrylate can be hydrolysed rapidly and completely under alkaline conditions however, the monomer units in polymethylmethacrylate (PMMA) prepared and treated similarly are resistant to hydrolysis although their benzoate end-groups react readily. Thus, saponification techniques should be applied with caution to polymeric materials. 

It is quite amazing that so few different plastics are used in packaging. The most common ones are polyethylene (low and high density), polypropylene, polystyrene, and poly(ethylene terephthlate). All of these materials can easily be recycled because they are thermoplastics. Incidentally, vinyls (polyvinyl chloride) are becoming less common in packaging. 

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