2.6- Naphthalenedicarboxylate

Naphthalenedicarboxylic Acid. This dicarboxyhc acid, a potential monomer in the production of polyester fibers and plastics with superior properties (105), and of thermotropic Hquid crystal polymers (106), is manufactured by the oxidation of 2,6-dialkylnaphthalenes (107,108). 

The autoclave is cooled to room temperature, and the carbon dioxide is bled off. The solid reaction product is taken from the autoclave, pulverized, and dissolved in 1 1. of water at 50-60°. Ten grams of decolorizing carbon is added, and the mixture is stirred well and filtered to remove cadmium salts and carbon. The filtrate is heated to 80-90° and acidified with concentrated hydrochloric acid to pH 1 (Note 5). 2,6-Naphthalenedicar-boxylic acid precipitates. It is separated from the hot mixture by filtration. It is then suspended in 500 ml. of water at 90-95° (Note 5), separated by filtration, and washed successively with 300 ml. of water, 300 ml. of 50% ethanol, and 300 ml. of 90% ethanol. After being dried at 100-150°/150 mm. in a vacuum oven, the 2,6-naphthalenedicarboxylic acid weighs 42-45 g. (57-61%). It decomposes on a heated block at 310-313°. 

Naphthalenedicarboxylic acid has been prepared by fusing dipotassium 2,6-naphthalenedisulfonate with potassium cyanide to give the corresponding dinitrile, which is hydrolyzed by oxidation of 2-methyl-6-acetylnaphthalene with dilute nitric acid at 200 by the thermal disproportionation of potassium a- or /3-naphthoate to dipotassium 2,6-naphthalenedicarboxylate and naphthalene and by the present method. The present method is much more convenient than earlier methods, if a suitable autoclave is available. 

Photophysical Processes and Photodegradation of Poly(ethylene terephthalate-co-2,6-naphtha1enedi carboxyl ate) Copolymers. We have recently reported the photophysical processes and the photo-degradative behavior of Doly(ethylene terephthalate-co-2,6-naphthalenedicarboxyl ate), PET-2,6-ND, copolymer yarns containing 0.5 - 4.0 mole percent 2,6-naphthalenedicarboxyl ate, 2,6-ND (1) and the parent naphthalenedicarboxyl ate monomer, Figure 3 and 4. 

Figure 3. Electronic energy level diagram and transitions for polyfethylene tereph-thalate-co-2,6-naphthalenedicarboxylate) yarn (9)...

The separation method targets recovery of the aqueous phase from oil/water mixtures of microbial reactions by filtration through a ceramic filter module [154], The invention particularly referred to a two-phase system resulting from a process used for production of 2,6-naphthalenedicarboxylic acid using S. paucimobilis AK2M16 (PERM P-13996). The aqueous phase is said to be recovered free of microbial cells and oil. Although, it is mentioned that the reaction product can be recovered readily in high yield, the need for an additional unit operation looks obvious. 

H Jagt, Y Dirix, R Hikmet, and C Bastiaansen, Linear polarizers based on polymer blends oriented blends of poly(ethylene-2,6-naphthalenedicarboxylate) and a poly(styrene/methylmethacrylate) copolymer, Jpn. J. Appl. Phys., 37 4389-4392, 1998. 

Pelletizing, in pyrometallurgy, 16 140 Pelouze reaction, 17 227 Peltier effect, 21 555 24 428 Pelton wheel turbine, 26 85 Pemanent Red 2B, Strontium Salt, pigment for plastics, 7 366t PEM fuel cell (PEMFC), 12 202-203 PEN, 10 222. See also Poly(ethylene 2,6-naphthalenedicarboxylate) (PEN) Penaeid shrimp, aquacultural chemical needs, 3 209... 

CHDA CHDM DMCD EG IPA N NDA PCT PCTA PCTG PET PETG TMCD TPA cis/trans-1,4-cyclohexanedicarboxylic acid cis/trans-1,4-cyclohexanedimethanol dimethyl cis/trans-1,4-cyclohexanedicarboxylate ethylene glycol isophthalic acid dimethyl 2,6-naphthalenedicarboxylate 2,6-naphthalenedicarboxylic acid poly(1,4-cyclohexylenedimethylene terephthalate) dibasic-acid-modified PCT copolyester glycol-modified PCT copolyester poly(ethylene terephthalate) CHDM-modified PET copolyester c .S / ra .v-2,2,4,4-tetramethyl-l,3-cyclobutancdiol terephthalic acid... 

CHDM-BASED COPOL YESTERS WITH DIMETHYL 2,6-NAPHTHALENEDICARBOXYLATE... 

Modification of PCT with increasing levels of the 2,6-naphthalenedicarboxylate moiety (N) has been reported. The effects of increasing levels of N on the thermal properties of PCT are shown in Figures 7.11 and 7.12 [61]. 

CHDM copolyesters containing residues of 2,6-naphthalenedicarboxylate, 4,4 -biphenyldicarboxylic acid and CHDM are reported to exhibit high heat resistance [91]. 

Although PEN is a fifty-year-old polyester product it is only now just beginning to make a major appearance into the marketplace. It was first synthesized as a laboratory curiosity in 1948 by ICI scientists [4], Dimethyl-2,6-naphthalenedicarboxylate (NDC) is the primary starting monomer, along with glycol. The key to further development of PEN is to produce the diacid, 2,6-naphthalenedicarboxylic acid (NDA), on a commercial scale. This is a major... 

The monomer used for the preparation of PEN is dimethyl-2,6-naphthalenedicar-boxylate (NDC) or 2,6-naphthalenedicarboxylic acid (NDA). During the long development time, several synthetic methods were developed and the manufacturing processes were improved, which finally reduced the cost for the commercialization of PEN [5-10], The main synthesis routes are described in the following. 

Since it is also a poly condensation polymer, the preparation of PEN from dimethyl 2,6-naphthalenedicarboxylate (NDC) is similar to the preparation of PET from dimethyl 1,4-terephthalate (DMT) by combining a diacid ester (NDC) with ethylene glycol. In view of the fact that the commercial-scale production of PEN resin starts with 2,6-NDC, the production process is similar to that used for the production of PET from DMT. There are two main steps for the process (Scheme 10.1) [11]. 

A biaxially oriented polyester film made of a copolymer consisting of 80 % ethylene 2,6-naphthalenedicarboxylate has excellent adhesion, surface hardness and wear resistance, while also providing significant transparency and antireflection properties. This material, when laminated to glass, is excellent for the prevention of shattering [82],... 

Diethylnaphthalene from 2.6- diethylnaphthalene, 2.6- naphthalenedicarboxylic add KY n-Heptane, p-diethylbenzene [53]... 

NICNAS. 2,6 Naphthalenedicarboxylic acid. Full Report File No. NA/503, National Indusitrial Chemicals Notification and Assessment Scheme, Commonwealth of Australia, 1997. 

---