Ethylene terephthalate - hydroxybenzoate copolymer

Other recent applications of ToF-SIMS without XPS include the examination of PS [6, 17-19], polyethylene (PE) [20], carbon fibre reinforced epoxy resins [21], polyalkyl methacrylates [22], alkylketene dimers [23], perfluorinated polymers [24], perflnorinated ethers [25], polyethylene glycol (PEG) oligomers [15, 25-29], rubber [30], ethylene-tetrafluoroethylene copolymer [30], Nylon-6 [31], PC [32,33], PDMS [34], polypyrrole coated PS [35], poly-p-phenylene vinylene [36], butyl rubber [37], poly(4-vinyl phenol)/poly(4-vinyl pyridine blends) [38], polypyrrole-silica gel composites [39], y-glycidoxypropyl trimethoxy silane [40], triblock copolymer poly(ethylene glycol)- 3 poly(phenylene ethylene)- 3 poly(ethylene glycol) [41], ethylene-terephthalate-hydroxybenzoate copolymer [42], PS-polyvinyl methyl ether, polycarbonate - PS blends [43] and PDMS-urethane [44],... 

This paper will describe our analyses of the structures of copolyesters, concentrating on the system studied in most detail the terpolymer prepared from 4-hydroxybenzoic acid, 2,6-dihydroxy-naphthalene (DHN), and terephthalic acid (TPA). We will also discuss analyses of the structure of HBA modified poly(ethylene terephthalate), in which the presence of -CH2-CH2 groups in the backbone leads to a more flexible chain. Other work on the copolymers of HBA and HNA is described in the following paper by Chivers et al. [3]... 

For most of the results discussed below, the following is valid concerning COP, PC and mixtures if not otherwise stated. The thermotropic copolyester derived from p-hydroxybenzoate and poly(ethylene terephthalate) [10] containing 60 mol% PHB was used exclusively as the PLC component because this composition has the best mechanical properties [10,118] of these copolymers. It was obtained from Eastman Kodak, Kingsport, TN, and had an average molar mass estimated from solvent viscosity of about 19000 g mol . The sequence distribution was calculated from C-NMR as described by Lenz et al. [119] and was nearly random the statistical parameter which describes the randomness of the copolymer is = 1 for a block copolymer and P = 0 for a completely random copolymer. The copolymer used for the experiments had P = 0.15. 

In this and the following two sections we consider the data for a PLC and for different blends of that PLC with isotactic polypropylene (PP). The PLC used in this study was liquid crystalline copolyester PET/0.6PHB, where PET = poly (ethylene terephthalate), PHB = p-hydroxybenzoic acid and 0.6 is the mole fraction of PHB in the copolymer, manufactured by Unitika Ltd, Kyoto, Japan. The content of the PLC in the blends with PP was varied from 0 to 20 wt%. The samples were prepared by injection molding. PP, resin VB65 llB, was supplied by Neste OY, Finland. 

A few studies have been made on polyarylates (i.e., copolymers of hydroxybenzoic acid with other ester-forming co-condensates), some of which provided information on oxidative degradation [30-32]. As might be expected, in the case of a hydroxybenzoate-co-ethylene terephthalate, the two parts of the copolymer degrade separately the PET first via the usual pathways, and the hydroxybenzoate unit later by a depolymerisation route with the formation of phenol and carbon dioxide. 

Unlike poly(ethylene terephthalate), the polyester from dimethyl terephthalate and cyclohexane-1,4-dimethylol can be manufactured with initially equivalent monomer quantities. It has improved dyeability, just as in the case of the copolymer of dimethyl terephthalate, ethylene glycol, and 5-10% p-hydroxybenzoic or isophthalic acid. 

In Section 24.1 we have defined ways of prediction of long-term behavior from short-term tests. Let us now provide more examples of application of these concepts. Creep and stress relaxation have been determined for PET/ 0.6PHB, where PET is the poly(ethylene terephthalate), PHB, the p-hydroxybenzoic acid, and 0.6 is the mole fraction of the latter in the copolymer [58]. PET/0.6PHB is a polymer liquid crystal, see chapter 41 on PECs in this Handbook. In temperature ranges of interest it forms 4 coexisting phases [60]. Conventional wisdom said that prediction methods work only for so-called rheologically simple materials, practically for one-phase polymers. Therefore, we have decided to apply as severe a test as possible to our prediction methods and a multiphase PLC is a good choice. 

A mention must be made of the copolymers of poly(ethylene terephthalate) and p-hydroxybenzoic acid which forms a thermotropic system (liquid-crystalline... 

Brostow W, Hess M, Lopez BL. Phase structures and phase diagrams in polymer liquid-crystal systems copolymers of poly(ethylene terephthalate) andp-hydroxybenzoic acid. Macromolecules 1994 27 2262-9. 

Pig. 16. The temperature shift factor ot (T) for PET/0.6PHB polymer liquid crystal (PET = poly(ethylene terephthalate, PHB = p-hydroxybenzoic add, 0.6 = mole fraction of PHB in the PLC copolymer). Explanations in text (64). 

Copolymers from ethylene terephthalate and p-hydroxybenzoic acid... 

Ethylene terephthalate/p-hydroxybenzoic acid copolymer polycarbonate-bisphenol-A and trichloromethane 88SCH... 

Other thermoplastic polyesters have been reported, including copolyesters based on 1,4-cyclohexylenedimethylene glycol and terephthalic acid and polymers and copolymers of p-hydroxybenzoic acid. Little is known about established applications. Hot melt adhesives, based on polyesters made from adipic or phthalic acids with mono- or di-ethylene glycols or 1,4-butane diol, find use in shoe manufacture. 

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