Poly l,4-cyclohexylenedimethylene

Fibres are also available from poly-(l,4-cyclohexylenedimethylene terephthalate) and are marketed as Kodar (Kodak) and Vestan (Hills). 

Poly(l,4-cyclohexylenedimethylene terephthalate) (PCT) finds some niche applications in the packaging market as amorphous, clear, extrusion, or injectionmolding material for films and bottles. 

See also PBT degradation structure and properties of, 44-46 synthesis of, 106, 191 Polycaprolactam (PCA), 530, 541 Poly(e-caprolactone) (CAPA, PCL), 28, 42, 86. See also PCL degradation OH-terminated, 98-99 Polycaprolactones, 213 Poly(carbo[dimethyl]silane)s, 450, 451 Polycarbonate glycols, 207 Polycarbonate-polysulfone block copolymer, 360 Polycarbonates, 213 chemical structure of, 5 Polycarbosilanes, 450-456 Poly(chlorocarbosilanes), 454 Polycondensations, 57, 100 Poly(l,4-cyclohexylenedimethylene terephthalate) (PCT), 25 Polydimethyl siloxanes, 4 Poly(dioxanone) (PDO), 27 Poly (4,4 -dipheny lpheny lpho sphine oxide) (PAPO), 347 Polydispersity, 57 Polydispersity index, 444 Poly(D-lactic acid) (PDLA), 41 Poly(DL-lactic acid) (PDLLA), 42 Polyester amides, 18 Polyester-based networks, 58-60 Polyester carbonates, 18 Polyester-ether block copolymers, 20 Polyester-ethers, 26... 

PCT describes a polyester composition prepared from CHDM and DMT (or TPA). The abbreviation PCT is thus derived from the technical name for the polymer, i.e. poly(l,4-cyclohexylenedimethylene terephthalate), or PCT. This material is a highly crystalline, high-melting polyester, with the following structure ... 

Minnick, L. A. and Seymour, R. W., Poly(l,4-cyclohexylenedimethylene terephthalate) with improved melt stability, US Patent 5 428 086, 1995. 

Minnick, L. A., Reinforced molding composition based on poly(l,4-cyclohexylenedimethylene terephthalate) having improved crystallization characteristics, US Patent 4 859 732, 1988. 

Hill, A.J., Winhold, S Stack, G.M., Tant, M.R. (1996) Effect of copolymer composition on free volume and gas permeability in polyethylene terephthalate) -poly(l,4 cyclohexylenedimethylene terephthalate) copolymers . Eur. Polym. J. 32(7), 843. 

The primary crystalline polymer based on CHDM is the terephthalate, poly(l,4-cyclohexylenedimethylene terephthalate) (PCT). This polyester was originally developed for fiber applications but has since found wider utility as a reinforced polymer for injection molding and (when copolymerized with a small amount of isophthalic acid) as a material for crystallized food packaging trays. The key property of PCT which sets it apart from other thermoplastic polyesters in tliese latter applications is its melting point. 

Eastman Chemical Company Product Literature [www.Easlman.com]. Minnick, L. A. and Seymour, R. W., Poly(l,4-cyclohexylenedimethylene terephdialate) with improved melt stability, US Patent 5 428 086, 1995. Minnick, L. A., Polyester molding composition, US Patent 4 778820, 1987. Auerbach, A. B. and Sell, J. W., Evaluation of poly(l,4-cyclohexylenedi-methylene terephdialate) blends for improved processability, Polym. Eng. ScL, 30, 1041 (1990). 

Y. G. Jeong, W. H. Jo, and S. C. Lee. Synthesis and isodimor-phic cocrystallization behavior of poly(l,4-cyclohexylenedimethylene tere-phthalate-co-1,4-cyclohexylenedimethylene 2,6-naphthalate) copolymers. J. Polym. ScL, Part B Polym. Phys., 42(1) 177-187, January 2004. 

OOIij lijima, T., Hamakawa, S., Tomoi, M. Preparation of poly(l,4-cyclohexylenedimethylene phthalate)s and their use as modifiers for aromatic diamine-cured epoxy resin. Polym. InL 49 (2000) 871-880. 

Poly(l, 4-cyclohexylenedimethylene terephthalate-co-l,4-cyclohexylenedimethylene 2,6-naphthalate) (P (CT-co-CN)) copolymers behave similarly with respect to crystallization behavior as poly(ethylene-co-hut-ylene 2,6-naphthalate) copolymers [32], Poly(ethyle-ne 2,6-naphthalate-co-1,4-cyclohexylenedimethylene 2,6-naphthalate) (P(EN-co-CN)) copolymers do not crystallize in the middle of copolymer composition, whereas poly(butylene 2,6-naphthalate-co-l,4-cyclo-hexylenedimethylene 2,6-naphthalate) (P(BN-co-CN)) and poly(hexamethylene 2,6-naphttialate-co-l, 4-cyclohexylenedimethylene 2,6-naphthalate) (P(HN-co-CN)) copolymers exhibit clear melting and crystallization peaks. This behavior indicates that both P (BN-co-CN) and P (HN-co-CN) copolymers exhibit a co-crystallization behavior. P(BN-co-CN) copolymers exhibit a eutectic melting and isodimorphic cocrystallization. 

Other aromatic polyesters which have been commercialised include poly(l,4-cyclohexylenedimethylene terephthalate) (PCT used in the production of circuit board components and automotive applications) and the clear, amorphous, polymer poly(l,4-cyclohexylenedimethylene terephthalate-co-isophthalate). 

Various copolymers based on this chemistry have also been commercialised, including poly(ethylene-co-l,4-cyclohexylenedimethylene terephthalate) and poly(l,4-cyclohexylenedimethylene terephthalate-co-isophthalate). Both of these types are largely amorphous, clear, polymers. 

A few studies have been made on the thermal degradation of poly(l,4-cyclohexylenedimethylene terephthalate) [84—86], although these have little to say concerning the likely breakdown mechanism. Assuming the same process is applied here as in straight-chain poly(alkylene terephthalate)s, the process might be deduced as follows [NB (CgHjo) denotes the 1,4-cyclohexyl moiety in the polymer backbone] ... 

Phosphite or phosphate and diepoxy compound in poly(l,4-cyclohexylenedimethylene terephthalate) [33]... 

Monomers containing the 1,4-cyclohexylene unit are interesting because they are potentially biobased and rigid enough to improve the glass transition temperature as well as the melting temperature (2). The preparation of poly(l,4-cyclohexylenedimethylene adipate) has been described. 

The effect of initial humidity put into evidence in this series of determinations agrees with the results obtained by Wampler [792] on poly(l,4-cyclohexylenedimethylen-terephthalate) when, with increases of humidity over 20 ppm, concentration of the -COOH groups in the extrudate suddenly increases. 

Dynamic mechanical analysis has also been used to determine the mechanical and thermal properties of low-density polyethylene and ethylene-propylene-diene terpolymer containing jute filler, which had improved flexural and impact properties compared to those of the base polymer [198]. Jeong and coworkers [196] and others [195] investigated the dynamic mechanical properties of a series of polyhexamethyl-ene lerephthalale, poly(l,4-cyclohexylenedimethylene terephthalate), and random copolymers thereof in the amorphous state as a function of temperature and frequency. The effect of copolymer composition on dynamic mechanical properties was examined and the dynamic mechanical properties interpreted in terms of the cooperativity of segmental motions. 

Poly(l,4-cyclohexylenedimethylene succinate) (PCDS) (Figure 6.2), can be produced by the distannoxane-catalyzed polycondensation of succinic acid and 1,4-CHDM (18). The crystal structure of frans-PCDS studied by X-ray and electron diffraction revealed that this polyester crystallizes with a unit cell ofa = 0.649 nm, b = 0.948 nm and c = 1.351 nm, and P = 49.5° in the space group Pljn (19,20). 

Riande et al. (21,22) synthesized the cis and tmns isomers of PCDS as well as the trans isomer of poly(l,4-cyclohexylenedimethylene adipate) (PCDA), and studied their polarity by measurements of dielectric constants and dipole moments. They observed that the trans isomer exhibited lower polarity than the cis one, and that the dipole moment decreased with the number of methylene groups of the diacid unit. The configurational properties of the two PCDS isomers were comparatively examined, both experimentally and theoretically, using the rotational isomeric state model. 

The most widely known aromatic homopolyester made of 1,4-CHDM is doubtless poly(l,4-cyclohexylenedimethylene tereph-thalate) (PCT) (Figure 6.5). This polyester, which was firstly developed in 1959 by Tennesee Eastman Co. for its utilization in the fiber industry with the trade name of Kodel, is nowdays produced by two-step melt phase polycondensation from DMT and 1,4-CHDM. When high molecular weight PCT is desired, the... 

The polycondensation in solution method was also the method applied for the synthesis of poly(l,4-cyclohexylenedimethylene succinate) PCDS referred before (18). The molecular weight of the polymer increased with the boiling point of the solvent employed so highest molecular weights were achieved in n-decane at 215 °C with l-chloro-3-hydroxy-l,l,3,3-tetrabutyldistannoxane as catalyst. 

The large variety of polyesters or copolyesters that can be obtained with 1,4-CHDM make these products usable in a broad range of applications. Thus aliphatic polyesters and copolyesters are produced to generate biodegradable or biocompatible objects, as it is the case of poly(l,4-cyclohexylenedimethylene fumarate), with application in the manufacture of bioresorbable bone cement composites (27). Polyoxaesters of 1,4-CHDM are a new class of synthetic absorbable polyesters with potential surgical applications as suture coatings, or adhesion prevention barriers (28). 

Composites from poly(l,4-cyclohexylenedimethylene fumarate) crosslinked with polyvinyl pyrrolidone in the presence of calcium sulfate dehydrated filler have been prepared. These composites showed high modulus and compressive strength compared to other fumarate-based polyesters. Possible applications of this material in the field of bone cement composites have been pointed out (27). 

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