Polyethylene Terephthalate PETP

The formation of new end-carboxyl groups leads to the additional production of CO as a result of decarboxylation. Vinyl ester groups decompose to produce radicals  

After abstracting in a secondary hydrogen atom, radicals initiate the reaction via a chain mechanism. In this case a benzaldehyde end-group and acetaldehyde are 

On decomposition of the alkyl radical, terminal benzyl and acetaldehyde radicals are formed  

The formation of formaldehyde is evidently associated with cleavage of the C-C bond in the glycol link and subsequent decomposition of the radicals  

The compositions of the products of the thermal and thermo-oxidative degradation of PETP are the same, so the mechanism of initiation of these processes is identical. In this case, addition of oxygen to the products of the radicals promotes the development of degenerate branching. 

---

Figure 6 (A) Non-isothermal chemiluminescence runs for oxidation of polystyrene (PS), polyethylene terephthalate) (PETP) and polyfmethyl methacrylate) (PMMA), in oxygen, heating rate 2.5°C/min. (B) Non-isothermal chemiluminescence runs for oxidation of polypropylene (PP), polyamide 6 (PA 6), poly(vinyl pyrrolidone) (PVP), polyethylene (PE) and polyamide 66 (PA 66), in oxygen, heating rate 2.5°C/min.

The remarkable increase in the Melting point of polyesters formed by the incorporation of the aromatic ring is because of the stiffening of the polymer backbone. Thus, a polyester like polyethylene terephthalate (PETP) has a high Melting point due to the presence of the aromatic ring and is commercially the most popular polymers marketed under the trade name of Terylene or Terene. 

A thermoplastic is a material which can be deformed permanently and repeatedly by heat and pressure. Complete recycle is often difficult because of contamination or degradation, but polyethylene terephthalate (PETP) is easily recycled, i.e. the action of heat and pressure is reversible. 

The aliphatic polyester has a melting point of about 65°C, whereas the aromatic substituted dicarboxylic acid has a melting point of 265°C. Thus, the polyester polyethylene terephthalate (PETP) is commercially one of the most popular polymers marketed as Terylene or terene. 

Wegener M, Wirges W, Gerhard-Multhaupt R (2005a) Piezoelectric polyethylene terephthalate (PETP) foams speeifieaUy designed and prepared ferroelectret films. Adv Eng Mater 7 1128 1131... 

The glass transition, denoted p (or a ), is almost worth its own chapter. The amorphous component is constrained by the crystals and the glass transition is much broader in a semicrystalline polymer than in a fully amorphous polymer. Polyethylene terephthalate (PETP) can be quenched to a fully amorphous state and it can be crystallized to 60% at elevated pressures. Figure 7.49 shows the dielectric loss process (Wg) and the great difference between two PETP samples of different crystallinity. The amorphous polymer displays a sharper ot transition than the crystalline. The amorphous polymer shows a clearly asymmetric curve, whereas the semicrystalline polymer shows a symmetric curve. 

Sviridyonok et al. studied the transfer between polymer and polymer. Several polymers with known critical surface tension Yc were used for the study PTFE, (18.5 dyne/cm), polyethylene (31 dyne/cm) PMMA - (39 dyne/cm) polyethylene terephthalate (PETP) -(43 dyne/cm) polycaprolamide (PCA) - (46 dyne/cm). The results indicate that a polymer generally transfers from less to more polar polymer surfaces. For highly polar polymers, the transfer mechanism appears to be accompanied by formation and interaction of free radicals. This interesting work shows that finally surface energetics appear to be involved directly in polymer transfer. 

LDPE Low-density polyethylene PET, PETP Poly(ethylene terephthalate)... 

Notes Cellulose (Whatman) PTMSP, poly(trimethyl silyl propine) PS, polystyrene PP, polypropylene PE, polyethylene PA 66, polyamide 66 PA 6, polyamide 6 PVP, poly(vinyl pyrrolidone) PPO, poly(2,6-dimetyl-l,4-phenylene oxide) PMMA, poly(methyl methacrylate) PETP, polyethylene terephthalate) Irganox 1010 is a Ciba anti-oxidant. 

Polyethylene terephthalate melts at round 265°C and is resistant to heat and moisture. It remains virtually unattached by most of the chemicals. It is extensively used to make textile fibres. It has good mechanical strength up to 175°C. Garments prepared from its fibres resist the formation of wrinkless. PETP can also be... 

EXPLOSIVES AND PROPELLANTS - EXPLOSIVES] (Vol 10) PETP. See Polyethylene terephthalate). 

Research of influence of introduction of hexsaazocyclanes on a microstructure of polyethylene terephthalate is carried out. The increase in ability modified PETP to crystallization, in comparison with not modified PETP, as hexsaazocyclanes play a role of the original centers of crystallization is revealed. Research plasticization effect of hexsaazocyclanes on polyethylene terephthalate is carried out. It is revealed, hexsaazocyclanes introduction influences a maximum of a tangent of dielectric losses polyethylene terephthalate, displacing it aside smaller temperatures. 

Polyesters (PET or PETP) (earlier use as Terylene (trade mark), polyethylene terephthalate)... 

As a result of thermooxidative destruction, polyethylene terephthalate liberates the diethyl ether of terephthalic acid, acetaldehyde, methanol and carbon oxide. As investigations have shown, manufacture of PETP films or fibers has brought no change to the state of health of maintenance workers. Moreover, PETP films are used to preserve sterilized foodstuffs and warm up prepared dishes. 

PP = polypropylene PAS, 10 = Nylon 6,10 PETP = polyethylene terephthalate Reprinted from K. Bergmann, Polymer Bulletin, 1981, 5, 355, with permission from ... 

---