2.6- Dimethyl naphthalate

The copolymers are prepared using a mixture of dimethyl terephthalate and dimethyl naphthalate. Published data indicates a reasonably linear relationship between and copolymer composition on the lines discussed in Section 4.2, e.g. Tg for a 50 50 copolymer is about 100°C which is about mid-way between Tg figures for the two homopolymers. In line with most other copolymers there is no such linearity in the crystalline melting point (T, ). As comonomer levels are introduced drops from the values for both homopolymers and indeed crystallisation only readily occurs where one of the components is dominant, i.e. 80%. Thus commercial copolymers are usually classified into two types ... 

Chuah et al. [107] prepared a series of PTT/poly(trimethylene napthalate) (PTN) copolyesters by copolymerizing PDO with dimethyl terephthalate and dimethyl naphthalate. The PTN homopolymer has a 7 g of 75 °C and a Tm of 245 °C. Despite the more rigid napthalate moiety, the PTN Tg and Tm were much lower than the Tg of poly(ethylene naphthalate) (PEN), indicating the strong influence of the flexible trimethylene units. 

Depolymerization processes have been proposed for poly(butylene terephtha-late) by the glycolysis of PBT with 1,4-butanediol and a titanium catalyst [65]. Methanolysis of poly(ethylene naphthalate) to dimethyl naphthalate and ethylene glycol has also been proposed [66, 67], but not implemented. The lack of commercial depolymerization of PEN is probably due not to technical limitations, but to insufficient supplies of PEN polymer feedstock to meet the minimum quantities needed for economical operations. 

Supersolubilisation of NAPL can be achieved by adding lipophilic linkers to the system. Best results for chlorinated hydrocarbons were obtained with both hydrophilic and lipophilic linkers [71]. Lipophilic linkers increase the interaction between surfactant and oil [72], and hydrophilic linkers the interaction between surfactant and water. Systems with Aerosol MA as surfactant, sodium mono- and dimethyl naphthalate as hydrophilic linker, and dodecanol as lipophilic linker display the best performance regarding efficiency, economy and environmental aspects [65]. 

The PEN copolymer is prepared from 2,6-dimethyl naphthalate, dimethyl isophthalate, ethylene glycol, and poly(tetramethylene glycol), with an average molecular weight of 1,000 Dalton. 

Y. M. Sun and H. H. Liu. Novel copolyesters containing naphthalene structure III. Copolyesters prepared from 2,6-dimethyl naphthalate, ethylene glycol, and 2,2-dialkyl-l,3-propanediols. J. Appl Polym. ScL, 81(11) 2754-2763, September 2001. 

The first is the formation of 2,6-bis-(hydroxyethyl) arylate (BHEA) and bis-(hydroxymethylcyclohex-ane)-arylate (BHCA), respectively, from the transesterification of 2,6-dimethyl naphthalate or dimethyl terephthalate (DMT) with ethylene glycol or CHDM. The second step is the formation of PECA from polycondensation of the BHEA and BHCA mixture at elevated temperatures and reduced pressure [35]. 

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... 

Although the superior properties of PEN have been known for many years, the unavailability of the naphthalate monomer has delayed the development of commercial markets, until relatively recently (1995) when the Amoco Chemical Company offered high purity naphthalene-2,6-dimethyl dicarboxylate (NDC) in amounts of up to 60 million pounds per year. This diester is produced by a five-step synthetic route, starting from the readily available compounds, o-xylene and 1,4-butadiene [3], Prior to this, the NDC diester was obtained by extraction of 2,6-dimethylnaphthalene (DMN) from petroleum streams, where it was present in relatively low abundance. Oxidation of DMN to crude 2,6-naphthalene dixcarboxylic (NDA) is conducted by a similar process to that used for conversion of p-xylcnc to purified terephthalic acid (TA), crude NDA is esterified with methanol, and is then distilled to yield high purity NDC. Other companies (e.g. the Mitsubishi Gas Chemical Company) followed Amoco s introduction with lesser amounts of NDC. Teijin [4] has manufactured PEN for many years for its own captive uses in films. 

HEXAHYDRO - 4a,5 - DIMETHYL - 2(3H) - NAPHTHALE-NONE and 2-TRIMETHYLSILYLOXY-1,3-BUTADIENE AS A REACTIVE DIENE DIETHYL trans -4-TRIMETHYL-SILYLOXY-4-CYCLOHEXENE-1,2-DICARBOXYLATE. Sulfur substitution also continues to be of high interest, and three preparations on sulfide synthesis are included BENZYL SULFIDE DIALKYL AND ALKYL ARYL SULFIDES NEOPENTYL PHENYL SULFIDE and UNSYMMETRICAL DIALKYL DISULFIDES sec-BUTYL ISOPROPYL DISULFIDE. 

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. 

Trypan Blue. 3,3 /(3,3 -DimetliyI/T,i -Mpfte i-yl] 4,4 -diyl)bisDirect Blue 14 C.l. 23850 3,3 -[(3,3 -dimethyl-4,4 -bipheny]ene)bis(azo)]bis-(5-amino-4-hydroxy-2,7-naphthalenedisulfonic acid) tetra-sodium salt tetrasodium 3,3 -[(3,3 -dimethyI-4,4 -biphen-ylene)bis(azo)]bi s(5 -amino. 4-hydroxy-2,7 -naphthal enedi-sulfonate) sodium ditolyl -diazobis - 8-amino-1 -naphthol-... 

Either NDC or the acid itself can be used. Using the dimethyl ester, zinc acetate or manganese acetate as a catalyst at a reaction temperature of 180-260°C is needed to produce (jS-hydroxyethyl)naphthalate, or its low-molecular-weight prepol5mier. When the acid is used, no catalyst is needed for the first step of esterification. 

Poly( 1,3-propylene 2,6-naphthalate) (3GN) is synthesized from dimethyl-2,6-naphthalene dicarboxylate and 1,3-propanediol. The ingredients are reacted under atmospheric pressure under nitrogen in the presence of Ty-zorTM titanium tetraisopropoxide catalyst. The vessel is heated to 240°C over a period of about 330 min. At 188°C, methanol started to evolve. 

Copolymers were prepared by the melt condensation method using dimethyl 2,6-naphthalate. The crystallinity and the density of annealed films decrease with increasing content of comonomer and length of alkyl side chain in the comonomer. The alkaline resistance is considerably increased by the incorporation of a comonomer having an alkyl side chain. 

Naphthalates Physical properties and handling information for dimethyl 2,6-naphthalene dicarboxylate. Company Data Sheet N-2, BP Sales Administration and Customer Service, 150 West Warrenville Road, 605-CS 3, Naperville, Illinois 60563-8460, November 2004. 

Poly(ethylene-l,4-cyclohexanedimethylene arylate), 359 Poly(3,4-ethylenedioxythiophene), 109 Poly(ethylene glycol), 9 Poly(ethylene glycol diacrylate), 540 Poly(ethylene naphthalate), 29, 347, 349 Poly(ethylene oxide), 430, 499 Poly(elhylene terephthalate), 185, 256, 347, 351, 398 Poly(iV-elhyl-3-vinylcarbazole), 14 Poly(furfirryl alcohol), 162 Poly(l-hexyl-3,4-dimethyl-3,5-pyrrolylene), 22... 

Poly(butylene terephthalate) Poly(epsilon-caprolactone) Poly(2,6-dimethyl-1,4-phenylene oxide) Poly (ether imide) Poly(ethylene-2,6-naphthalate)... 

Oleth-9 PEG/PPG-8/3 laurate PEG-20 sorbitan triisostearate Sucrose ricinoleate solubilizer, hair coloring agents N,N-Dimethyl-N-lauric acid-amidopropyl-N-(3-sulfopropyl)-ammonium betaine N,N-Dimethyl-N-myristyl-N-(3-sulfopropyl)-ammonium betaine N,N-Dimethyl-N-palmityl-N-(3-sulfopropyl)-ammonium betaine N,N-Dimethyl-N-stearyl-N-(3-sulfopropyl)-ammonium betaine N,N-Dimethyl-N-tallow-N-(3-sulfopropyl)-ammonium betaine N,N-Distearyl-N-methyl-N-(3-sulfopropyl)-ammonium betaine solubilizer, hair colors Diethylhexyl 2,6-naphthalate solubilizer, hand cleaners Cetoleth-30... 

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