2,6-naphthalene dicarboxylate

Copolymers of diallyl itaconate [2767-99-9] with AJ-vinylpyrrolidinone and styrene have been proposed as oxygen-permeable contact lenses (qv) (77). Reactivity ratios have been studied ia the copolymerization of diallyl tartrate (78). A lens of a high refractive iadex n- = 1.63) and a heat distortion above 280°C has been reported for diallyl 2,6-naphthalene dicarboxylate [51223-57-5] (79). Diallyl chlorendate [3232-62-0] polymerized ia the presence of di-/-butyl peroxide gives a lens with a refractive iadex of n = 1.57 (80). Hardness as high as Rockwell 150 is obtained by polymerization of triaHyl trimeUitate [2694-54-4] initiated by benzoyl peroxide (81). 

It must finally be kept in mind that it is extremely easy to adjust the properties of polyesters to desired values by adding small quantities (usually less than 10%) of comonomers in starting monomer feed. Isophthalic, adipic, dodecanedioic, p-hydroxybenzoic acids or esters and diethylene glycol, cyclohexanedimethanol, or bisphenol-A are often used for this purpose. Examples of property adjustment are the modification of solvent diffusivity of PET membranes by the addition of low levels of isophthalate or naphthalene dicarboxylate units in polymer chains139... 

At constant PBT/PTMO composition, when the molar mass of PTMO block is >2000, partial crystallization of the polyether phase leads to copolymer stiffening. The properties of polyesterether TPEs are not dramatically different when PTMO is replaced by polyethers such as poly(oxyethylene) (PEO) or poly(oxypropylene). PEO-based TPEs present higher hydrophilicity, which may be of interest for some applications such as waterproof breathable membranes but which also results in much lower hydrolysis resistance. Changing PBT into a more rigid polymer by using 2,6-naphthalene dicarboxylic acid instead of terephthalic acid results in compounds that exhibit excellent general properties but poorer low-temperature stiffening characteristics. 

DECOMPOSITION OF POLYETHYLENE 2,6-NAPHTHALENE DICARBOXYLATE TO CONSTITUENT MONOMERS USING SUPERCRITICAL METHANOL... 

Figure 4. Effect of radiation on the poly(ethylene terephthalate-co-2,6-naphthalene-dicarboxylate) yarns mole % of 2,6-DMN (%) 0.0 (X) 0.5 fA) 1-0 (O) 2.0 ...

The decarboxylation of mercuric 3- and 4-nitro-l,8-naphthalene-dicarboxylates has been studied to determine substituent electronic effects [Eq. (83)] (95,96), since significant steric effects are unlikely. There is disagreement over the products. In an early study, 3- and 4-nitro-l,8-naphthalenedicarboxylates were found to undergo decarboxylation predominantly in the ring without the nitro group (95), consistent... 

The properties of PET can be modified by the incorporation of co-monomers. Typical examples of these are isophthalic acid (IPA) (influences stress cracking resistance and melting temperature), 2,6-naphthalene dicarboxylic acid (NDC) (improves mechanical properties and reduces gas permeability), cyclohexane... 

Stewart, M. E., Cox, A. J., and Naylor, D. M Reactive processing of poly(ethylene 2,5-naphthalene dicarboxylate)/poly(ethylene terephthalate) blends, Polymer, 34, 4060-4067 (1993). 

The manufacture of polyethylene naphthalate) (PEN) is carried out using dimethyl 2,6-naphthalene dicarboxylate (NDC) and EG and is similar to the manufacture of PET from DMT. The IV after the melt is typically in the range of 0.5... 

The SSP of PEN and co-polyesters based on 2,6-naphthalene dicarboxylic acid requires prolonged reaction times, which is obviously related to the rigidity of the monomers and therefore to both the reduced mobilities of the end groups and diffusion. Only a few detailed reports exist in the literature on this subject [31, 32], It should be noted that the analysis of PEN can become complicated due to its reduced solubility. 

The isomeric bibenzoic acids (BBs), would appear to share similar structural features with naphthalene dicarboxylic acid. Like the PET-naphthalate copolymers, PET-bibenzoates have been demonstrated to possess moduli and glass transitions temperatures which increase with increasing levels of rigid comonomer [37-39], Unlike the PET/PEN copolymers, when the symmetrical 4,4 - I f I f monomer is substituted into a PET backbone, virtually every composition of PET-BB is semicrystalline the 2,4- and 3,4- isomers of BB, when... 

One might expect that completely replacing the terephthalate unit in PCT with naphthalene dicarboxylate would make an interesting high-temperature polymer. However, such a polymer cannot be successfully prepared, because its melting point is above its degradation temperature. Reduction of the melting... 

Chuah, H. H Vinsan, R. W. and Maxwell, I. E., Polypropylene Naphthalene Dicarboxylate and its Copolymers in Research Awareness Bulletin, Shell Chemical Company, Houston, TX, November 1991, pp. 5-8. 

The modification of PET with naphthalene-2,6-dicarboxylic acid and other additional comonomers is a common measure in bottle manufacturing. Copolyesters based on this compound show excellent barrier properties. Such materials can be produced by addition of the desired amount of comonomer during polymer processing or by blending PET with poly(ethylene naphthalate) (PEN). Additionally, PEN can also be modified by other comonomers such as isophthalic acid (IPA) to improve the flow properties and reduce the melting point. The high price of naphthalene dicarboxylic acid is the reason for its limited application. The overall cost may be reduced by using TPA or IPA as comonomers. 

Tindall et al. has used cyclodextrin to fine-tune ion mobility. The addition of /i-cyclodextrin up to 8 mM in a 1 mM 2,6-naphthalene dicarboxylate pH 9 buffer increases the dynamic range of the analyte from 0.025 to lOOpg/mL. The analytes described were butyric, propionic, and acetic acids. 

PEN is produced from 26DMN analogously to how PET is produced fromp-xylene. The 26DMN is oxidized to dimethyl 2,6 naphthalene dicarboxylate and then polymerized with ethylene glycol to produce PEN. The 26DMN can be synthesized by a number of methods mentioned by Lillwitz [44]. 

Copolynaphthalene ester films were prepared by transesterification/esterifi-cation of dimethyl naphthalene dicarboxylate and dimethyl isophthalate with aliphatic diols by Hebrink et al. (1) and used in optical polarizing films with color shifts. 

The fluorescence is measured in dilute solution and in glassy PMMA for polyesters in which 2,6-naphthalene dicarboxylate is the rigid unit, and (CF iy+t is the flexible spacer. The anisotropy in the rigid medium demonstrates the existence of intramolecular energy migration, which becomes more important as y decreases from 5 to 1. The Forster radius is about 12 A in the bichromophoric compounds and 14 A in the polyesters. 

Fluorescence is measured in dilute solution of model compounds for polymers of 2,6-naphthalene dicarboxylic acid and eight different glycols. The ratio of excimer to monomer emission depends on the glycol used. Studies as functions of temperature and solvent show that, in contrast with the analogous polyesters in which the naphthalene moiety is replaced with a benzene ring, there can be a substantial dynamic component to the excimer emission. Extrapolation to media of infinite viscosity shows that in the absence of rotational isomerism during the lifetime of the singlet excited state, there is an odd-even effect In the series in which the flexible spacers differ in the number of methylene units, but not in the series in which the flexible spacers differ in the number of oxyethylene units. 

The kinetics of transition from the liquid crystal to the fully ordered crystal of flexible, linear macromolecules was studied by Warner and Jaffe 38) on copolyesters of hydroxybenzoic acid, naphthalene dicarboxylic acid, isophthalic acid, and hydro-quinone. The analytical techniques were optical microscopy, calorimetry and wide angle X-ray diffraction. Despite the fact that massive structural rearrangements did not occur on crystallization, nucleation and growth followed the Avrami expression with an exponent of 2. The authors suggested a rod-like crystal growth. 

A number of aromatic dicarboxylate esters were also found to undergo allylation with loss of the silyl group when photolyzed in the presence of allyltrimethylsilane in acetonitrile-methanol175. As illustrated in equation 35 the naphthalene dicarboxylate 339 evidently underwent allylation, but then subsequently underwent photochemical [2 + 2] cycloaddition to give the polycyclic product 340 in other cases the reaction stopped after allylation. 

DSC and DTA. They can be used to confirm suspicious glass transitions revealed by DSC and most important, they can further quantify molecular mobility associated with sub-glass transitions. For example, DSC analysis of poly (ethylene 2,6-naphthalene dicarboxylate) (PEN) only revealed the presence of a glass transition around 112 °C (Hardy et al., 2001). DMA analysis of the same sample, however, revealed two secondary relaxations below this glass transition (Hardy et al., 2001). In the case of humic materials, it is not uncommon for DSC to fail to detect clear thermal transitions due to their heterogeneous nature, which contributes to overlap/ broadening or washout of thermal transitions. As such,TMA and DMA represent powerful, complementary tools to DSC. 

Hardy, L., Stevenson, I., Boiteux, G., Seytre, G., and Schonhals, A. (2001). Dielectric and dynamic mechanical relaxation behaviour of poly(ethylene 2,6 naphthalene dicarboxyl-ate). I. Amorphous films. Polymer 42(13), 5679-5687. 

Hashimoto et al. [132] studied the fluorescence of the MCLC polyesters, poly[(ethylene terephthalate)-co-(p-oxybenzoate)], 66, and poly[(ethylene 2,6-naphthalene dicarboxylate)-co-(/ -oxybenzoate)], 67. The fluorescence of 66, both at relatively high concentration (5 x 10 3 mol dm-3) in hexafluoro-2-propanol,... 

Alkylene 2,6-Naphthalenedicarboxylate/PTME 2,6-Naphthalene-dicarboxylate Copolymers. Fifty percent alkylene 2,6-naphthalenedicar-boxylate/PTME 2,6-naphthalenedicarboxylate copolymers were prepared using each of the straight-chain, hydroxy-terminated diols from ethylene glycol (2G) to 1,10-decanediol (10G) (Table VIII). In contrast to many of the 50% alkylene terephthalate/PTME terephthalate copolymers of Table II, all of the 2,6-naphthalenedicarboxylate-based copolymers tested exhibit excellent tensile strength and tear strength regardless of the diol used or the melting point of the copolymer. As a consequence of their excellent properties, the 2,6-naphthalenedicarboxylate copolymers have been the subject of several patents (32,33,34). 

Figure 4. The melting points of 50% alkylene 2,6-naphthalene dicarboxylate/FT ME 2,6-naphthalenedicarboxylate copolymers as a function of the melting points of the corresponding poly(alkylene 2,6-naphthalenedicarboxylate) homopolymers...

PB PBI PBMA PBO PBT(H) PBTP PC PCHMA PCTFE PDAP PDMS PE PEHD PELD PEMD PEC PEEK PEG PEI PEK PEN PEO PES PET PF PI PIB PMA PMMA PMI PMP POB POM PP PPE PPP PPPE PPQ PPS PPSU PS PSU PTFE PTMT PU PUR Poly(n.butylene) Poly(benzimidazole) Poly(n.butyl methacrylate) Poly(benzoxazole) Poly(benzthiazole) Poly(butylene glycol terephthalate) Polycarbonate Poly(cyclohexyl methacrylate) Poly(chloro-trifluoro ethylene) Poly(diallyl phthalate) Poly(dimethyl siloxane) Polyethylene High density polyethylene Low density polyethylene Medium density polyethylene Chlorinated polyethylene Poly-ether-ether ketone poly(ethylene glycol) Poly-ether-imide Poly-ether ketone Poly(ethylene-2,6-naphthalene dicarboxylate) Poly(ethylene oxide) Poly-ether sulfone Poly(ethylene terephthalate) Phenol formaldehyde resin Polyimide Polyisobutylene Poly(methyl acrylate) Poly(methyl methacrylate) Poly(methacryl imide) Poly(methylpentene) Poly(hydroxy-benzoate) Polyoxymethylene = polyacetal = polyformaldehyde Polypropylene Poly (2,6-dimethyl-l,4-phenylene ether) = Poly(phenylene oxide) Polyp araphenylene Poly(2,6-diphenyl-l,4-phenylene ether) Poly(phenyl quinoxaline) Polyphenylene sulfide, polysulfide Polyphenylene sulfone Polystyrene Polysulfone Poly(tetrafluoroethylene) Poly(tetramethylene terephthalate) Polyurethane Polyurethane rubber... 

Polyethylene naphthalate (PEN) polyesters are made from 2,6-naphthalene dicarboxylic acid or 2,6-naphthalene dicarboxylic acid, dimethyl ester. They have higher temperature resistance than amorphous PET and are increasingly used in applications requiring heat sterilisation of the food/drink, although PEN at the moment is significantly more expensive. Table 10.5 lists commonly used substances in polyesters. 

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