Polyethylene terephthalate degradation products

High speed stirring has be claimed by Nozaki for giving block copolymers from polymer-monomer mixtures (775). Among the polymers which have been subjected to such a degradation are addition polymers (polyvinyl chloride, polystyrene, polyacrylamide) as well as cellulose derivatives, phenol-formaldehyde linear condensation products and polyethylene terephthalate. 

The thermal degradation of PE mixed with polyethylene terephthalate (PET) and PE only degradation were compared. The presence of small amounts of PET is quite possible with the mixture of PE, PP, and PS, which is generally considered as municipal waste plastics. The yields of product gases, liquids and residues from the degradation of PET and the mixtures of PET and PE in ratios of 1 9 and 2 8 are shown in Table 18.4. Unlike PE or PVC, no liquid products could be obtained from the degradation of PET. The decomposition of PET proceeds with the production of a large amount of pale yellow... 

Dimethylfuran and acrolein are products of degradation of biomass such as cellulose. They were used as starting materials in the synthesis of p-xylene, demonstrating the utilization of materials obtainable from biomass toward the synthesis of polyethylene terephthalate (Scheme 16.31) [33]. The key steps involve Lewis acid-catalyzed eyeloaddition followed by oxidation and further aromatization through acid-mediated dehydration. 

Polybutylene terephthalate and polyethylene terephthalate, even without the addition of stabilizers, exhibit good weathering resistance, which can be improved by carbon black. Figure 5.89. During photo-oxidative degradation, mostly chain cleavage, but no crosslinking occur. The main photo-oxidation products are CO, COj, and carbonic acids. 

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