Naphthalene-2,3-dicarboxylic

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). 

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 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... 

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. 

Stewart, M. E., Cox, A. J. and Naylor, D. M., Reactive processing of poly(ethylene-2,6-naphthalene dicarboxylate)/poly(ethyleneterephthalate) blends, Polymer, 34, 4060-4067 (1993). 

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]. 

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. 

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. 

Polymers that have bulky repeat units can have multiple secondary relaxations. If more than one secondary relaxation is found, then the slowest one has to be the JG relaxation, assuming that the latter is resolved. Excellent illustrations of this scenario are found by dielectric relaxation studies of aromatic backbone polymers such as poly(ethylene terephthalate) (PET) and poly(ethylene 2,6-naphthalene dicarboxylate) (PEN) [43]. The calculated To from the parameters, n and xa, of the a-relaxation are in good agreement with the experimental value of %jq obtained either directly from the dielectric loss spectra or from the Arrhenius temperature dependence of xjg in the glassy state extrapolated to Tg. The example of PET is shown in Fig. 46. 

Upon photosensitization with (- )-menthyl salicylate 48a (X = 2-OH), pyromel-litate 49a, 1- and 2-naphthalenecarboxates 41a and 42a, 2,3- and 2,6-naphthalene-dicarboxylates 43a and 91a, and/or 9-anthracenecarboxylate 73a in acetonitrile at 25 or -40°C, aryl vinyl ethers 87 (X = H or Cl) and 4-methoxystyrene 89 cyclodimerize to the corresponding cyclobutane derivatives 88 and 90 (only the trans isomers are chiral) in low to good yields (Scheme 15) [64]. However, the... 

Table 23 demonstrates the mesogenicity of polymers containing biphenylene-S j -tetracarboxylic imide. A comparison of series 9 and 10 in the table shows that replacement of pyromellitic dianhydride with BPTA in a copolymer with two moles of m-aminophenol and an aromatic diacid does not lead to mesogenic polymers. The assignment of an MI score of 4 compared to 2 for pyromellitic anhydride does however raise the MI as far as the borderline condition of MI=9.5 when 2,6-naphthalene dicarboxylic acid is the co-monomer. 

The search for basic principles to guide the development of more effective barrier materials based on condensation polymerization is ongoing. Advanced polyesters such as poly(ethylene 2,6-naphthalene dicarboxylate) or PEN have been reported to have as much as 5 times lower permeability than conventional PET however, proprietary considerations have prevented the publication of complete details concerning such materials. 

Poly(ethylene-2,6-naphthalene dicarboxylate) (PEN) with MDPE and/or PP... 

---