Polynaphthalenes

The formation ofC—C bonds between aromatic rings is an important step in many organic syntheses and can be accomplished by chemical, photochemical, or electrochemical means. As was noted earlier, fundamental considerations of the parameters for a dielectric which must be dealt with in designing a thermally stable, low-dielectric-constant polymer naturally lead one to consider rigid-rod, nonconjugated aromatic polymers containing no lossy functional groups. A structure such as poly(naphthalene) is a likely candidate. 

Poly(naphthalene) is chemically similar to poly(p-phenylene), which is an insoluble, infusible, low-molecular-weight polymer, all attributes that preclude application in thin-film form in microelectronics. Although these materials possess several very desirable properties, such as high glass transition tempera- 

In the nearly 1970s, Bergman and co-workers48,49 postulated that cis-hex-2-ene, 1,5-diyne (A) upon thermolysis would undergo a thermal rearrangement to the benzene 1,4-diradical intermediate (or, 1,4-dehydrobenzene, B), which could revert to starting material or collapse to the rearrangement product (C) [Eq. (8)]. 

Numerous synthetic and mechanistic studies were done to investigate this reaction further, and a variety of enediynes have been thermalized in the presence of radical traps such as 1,4-cyclohexadiene. Even though large excesses of radical traps were employed, the yields of the substituted benzenes were often moderate at best. Most important of all, Tour et al.50 demonstrated that 1,4-naphthalene diradicals generated in solution couple to eventually form a polymer [Eq. (9)]. 

Tour s work showed that polymerization is still a preferred process even though large excesses ofradical traps (1,4-cyclohexadiene) were employed. They obtained poly( 1,4-naphthalene) only as an insoluble brown powder by polymerization of 1,2-diethynylbenzene in benzene solution. This route appears to be an attractive approach to a new dielectric medium  

There are a few reports of poly(naphthalene) thin films. Yoshino and co-workers. used electrochemical polymerization to obtain poly(2,6-naphthalene) film from a solution of naphthalene and nitrobenzene with a composite electrolyte of copper(II) chloride and lithium hexafluoroarsenate. Zotti and co-workers prepared poly( 1,4-naphthalene) film by anionic coupling of naphthalene on. platinum or glassy carbon electrodes with tetrabutylammonium tetrafluoroborate as an electrolyte in anhydrous acetonitrile and 1,2-dichloroethane. Recently, Hara and Toshima prepared a purple-colored poly( 1,4-naphthalene) film by electrochemical polymerization of naphthalene using a mixed electrolyte of aluminum chloride and cuprous chloride. Although the film was contaminated with the electrolyte, the polymer had very high thermal stability (decomposition temperature of 546°C). The only catalyst-free poly(naphthalene) which utilized a unique chemistry, Bergman s cycloaromatization, was obtained by Tour and co-workers recently (vide infra). 

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The thermal stability of PNT from different polymerization methods is presented in Table 18.7. ft appears that the colored (dark brown) but transparent PNT -N film synthesized by VDP is the cleanest film among the polynaphthalenes from other polymerization processes that have been reported. These PNT-N films from VDP also have very low dielectric constants in comparison to poly(tetra-fluoro-p-xylylene) films. PNT-N and PNT-F films have higher dissociation temperatures (>570°C) and better thermal stability (>530°C), and no film cracking was observed until PNT-F was annealed at 600°C in nitrogen. Table 18.8 presents a summary of the different properties ofPNT-N and PNT-F prepared by the VDP process. 

Fig. 1 Building units of conducting polymers, (1) polyacetylene (PA) (2) polypyrrole (PPy), polythiophene (PTh), polyfurane (PFu) (3) polyphenylene (PP) (4) polyaniline (PANI) 5 polyindole (PIND) (6) polycarbazole (PCaz) (7) polyazulene (Paz) (8) polynaphthalene (PNa) (9) polyanthracene (PAnth) (10) polypyrene (PPyr) (11) polyfluorene (PFiu) (12) poly(isothionaphthalene) (PITN) (13) poly(dithienothiophene) (14) poly(thienopyrrole) (15) poly(dithienylbenzene) (1G) poly(3-alkylthiophene) (17) poly(phenylene vinylene) (18) poly(bipyrrole) (PBPy), poly(bithiophene) (PBT) (19) poly(phenylenesulfide) (20) 4-poly(thienothiophene) (21) poly(thienyl vinylene), poly(furane vinylene) (22) poly(ethylenedioxythiophene) (PEDOT).

Observations Polynaphthalenes were initially prepared by the thermolysis of... 

Physical and optical properties of selected poly naphthalenes are provided in Table 1. TABLE 1. Physical and Optical Properties of Selected Polynaphthalenes"... 

Syndiotactic polynaphthalene was used by Ruff et al. (3) as a birefringent component in multilayer p-polarizing optical films. 

Fig. 10a,b. TEM photographs a polylaurylmethyacrylate latex particles b polynaphthalene latex particles... 

Sodium polynaphthalene sulfonate Naphthalene-1,2,3,4-tetrahydride. See Tetrahydronaphthalene 1-Naphthalenol. Seel-Naphthol... 

Sodium naphthaiene-formaidehyde suifonate Sodium naphthalene-form-aidehyde suifonate poiymers. See Sodium polynaphthalene sulfonate... 

Aerosol OT-100% Methyl hydroxyethyl-cellulose Monawet MT-70E Nonoxynol-9 Tylose MH Grades Tylose MHB dispersant, suspension polymerizations Luviskol K17 Luviskol K30 Luviskol K60 Luviskol K90 dispersant, synthetic latex Sodium polynaphthalene sulfonate dispersant, synthetic polymers Daxad 11G... 

Three methods for the construction of chiral polynaphthalenes have been described. In the first case, 2,2 -dihydroxy-6,6 -binaphthalenes were subjected to the optimized asymmetric oxidative coupling conditions, yielding the corresponding chiral polymers (a). It was found that each biaryl coupling step during the polymerization process is independent of existing axial chirality... 

Ablusol LME Ablusol LMES. See Disodium lauramido MEA-sulfosuccinate Ablusol ML, Ablusol NL. See Sodium polynaphthalene sulfonate Ablusol NLA. See Ammonium naphthalene-formaldehyde sulfonate Ablusol NP4SF. See Ammonium nonoxynol-4 sulfate... 

Chromanol, 2,5,7,8-tetramethyl-2-(4,8,12-trimethyl tridecyl)-. See DL-a-Tocopherol 6-Chromanol, 2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-, acetate. See dl-a-Tocopheryl acetate 2-Chromanone. See Dihydrocoumarin ChromaOne . See Urethane-acrylate resin Chromasisi 87H, Chromasist 1487A. See Sodium polynaphthalene sulfonate Chromate(5-), bis (2-((4,5-dihydro-3-methyl-1-(2-methyl-4-sulfophenyl)-5-oxo-1H-pyrazol-4-yl) azo)-4-sulfobenzoato(4-))-, tetrasodium hydrogen. See Acid yellow 54 Chromate(3-), bis (3-hydroxy-4-((2-hydroxy-1-naphthalenyl) azo)-7-nitro-1-naphthalenesulfonato (3-))-, disodium hydrogen. See Acid black 52 Chromate (2-), (5-chloro-3-((4,5-dihydro-3-methyl-5-oxo-1-(3-sulfophenyl)-1H-pyrazol-4-yl) azo)-2-hydroxybenzenesulfonato (4-)) hydroxy-, disodium. See Acid red 183 Chromate copper arsenate CAS 11125-95-4... 

Crisotan R-5M] Crisotan R-20. See Sodium polynaphthalene sulfonate Crisp Film . See Food starch, modified Crispmint oil. See Spearmint (Mentha viridis) oil Cristobal ite... 

Daxad It, Daxad 11G, Daxad 13, Daxad 14B, Daxad 14LLS, Daxad 15, Daxad 16, Daxad 17] Daxad 19] Daxad 19L-33] Daxad 19L-42] Daxad 19LS. See Sodium polynaphthalene sulfonate Daxad 21. See Calcium lignosulfonate Daxad 23. See Sodium lignosulfonate Daxad 30] Daxad 30-3(7, Daxad 30S. See Sodium poiymethacryiate Daxad 31. See isobutyiene/MA copoiymer Daxad 32. See Ammonium poiymethacryiate Daxad 34. See Poiymethacryiic acid Daxad 34A9. See Ammonium poiymethacryiate... 

Dehscofix 912] Dehscofix 914] Dehscofix 914/AS] Dehscofix 914/ASL] Dehscofix 915] Dehscofix 915/AS] Dehscofix 915/ASL. See Sodium polynaphthalene sulfonate Dehscofix 916] Dehscofix 916S. See Sodium diisopropyl naphthalene sulfonate Dehscofix 917. See Sodium dibutyl naphthalene sulfonate... 

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