Durene polymers

Wang GM, van Beylen M (2003) Influence of 7t-complexing agents on the anionic polymerization of styrene with lithium as counterion in cyclohexane. 1. Effect of durene. Polymer 44 6205-6210... 

The pyromellitic dianhydride is itself obtained by vapour phase oxidation of durene (1,2,4,5-tetramethylbenzene), using a supported vanadium oxide catalyst. A number of amines have been investigated and it has been found that certain aromatic amines give polymers with a high degree of oxidative and thermal stability. Such amines include m-phenylenediamine, benzidine and di-(4-amino-phenyl) ether, the last of these being employed in the manufacture of Kapton (Du Pont). The structure of this material is shown in Figure 18.36. 

Polyether S5mthesis by nucleophilic substitution is possible under conditions leading to solid polymer during the reaction. For example dimethylol durene... 

Bulle-Lieuwma CWT, van Gennip WJH, van Duren JKJ, Jonkheijm P, Janssen RAJ, Niemantsverdriet JW (2003) Charaderization of polymer solar cells by TOF-SIMS depth profiling. Appl Surf Sci 203-204 547... 

The 1,2,4,5-tetrasubstitution pattern confers a symmetrically opposed pair of dipoles on the molecule which, in turn, inposes enhanced crystallinity and accounts for its high melting point compared to the other tetramethyl benzenes prehnitene and isodurene (MP -6°C and -24°C respectively(4)). One use of durene and its derivatives, therefore, is to increase the crystallinity of polymers. For example, consider the glass transition points of polyamides if a polyamide is made from a diamine and, say, sebacic acid, durene diamine raises the glass transition temperature of the polymer more than 40°C above that produced by 1,4-diaminobenzene (5). 

There is an alternative method of making functional derivatives for polymerization. Durene can be condensed with formaldehyde in the presence of hydrochloric acid and zinc chloride to give the bis-chloromethyl durene(75). This can be converted into a number of derivatives from which polymers can be made, e.g. durene-1,4-dicarboxylic acid for polyamides(76), the diacetic acid for polyesters(77,78) or for polyamides(79), the diisocyanatomethyl derivative for polyureas and polyurethanes(80,81), the dimethanol derivative for polyurethanes(82) and for epoxies(83), while the bis chloromethyl derivative has also been proposed for making polyethers (with bisphenol A)(84). In each case, the attraction from the durene derivative has been the introduction of higher melting points and inproved softening properties. None of these polymers have been commercialized, possibly in part because of the difficulty of obtaining durene at suitable-prices. 

Milling anhydr MgCl2 with aromatic materials (e.g., naphthalene, durene) or polymers (e.g., polyethylene) forms stable free radicals that are radical cations supported on MgCl2... 

AI3-25182 Benzene, 1,2,4,5-tetramethyl- Durene Durol EINECS 202-465-7 NSC 6770 1,2,4,5-Tetramethylbenzene p-Xylene, 2,5-dlmethyl-. Used In organic synthesis, plasticizers, polymers, fibers. An agricultural chemical used as a fungicide, bactericide and wood preservative. Crystals mp = 79,3° bp = 196,8° d = 0,8380 Xm = 278 nm (cyclohexane) insoluble in H2O, soluble in EtOH, EtzO, MezCO, CeHs, CCI4, petroleum ether LDso (rat orl) = 6989 mg/kg. 

In addition to these more obvious derivatives, many specialty aromatics are available in such high proportion as to change the economics of the polymers based on them. A notable example is durene (l,2,4, -> tetramethylbenzene), a starting material for p omel-litic dianhydride, which is reacted with diamines to give the high-temperature-resistant polyimides. 

The semiconductive polymer can be deposited from a 10-30 mgml solution in an appropriate aromatic hydrocarbon such as toluene, xylene, durene, mesitylene, tetrahydronaphthalene, chlorobenzene, or other solvents such as cyclohexanone, tetrahydrofuran, chloroform, trichloroethane, by spin-casting at 1,000-8,000 rpm. Alternatively, the semiconductive polymer can be drop-cast or inkjet printed from these solutions. 

Dhanabalan A, van Duren JKJ, van Hal PA, van Dongen JLJ, Janssen RAJ (2001) Synthesis and characterization of a low bandgap conjugated polymer for bulk heteiojnnctitm photovoltaic cells. Adv Fund Mater 11 255... 

If deprotonation of a polymethylbenzene complex is carried out in the presence of an excess base and compatible electrophile such as an alkyl iodide or allyl- or benzyl bromide, the deprotonation-alkylation sequences spontaneously follow one another in situ until steric inhibition is reached. This reaction has been exploited with arene = CgMeg for the synthesis of star-shaped molecules (examples below) and living polymers and with arene = durene or mesitylene for the synthesis of dendritic cores (see for instance Chap. 21.2.2). 

Tetramer te-tro-mor n (1929) A polymer formed from four molecules of a monomer and/or made up of four mer units. See Oligomer. 1,2,4,5-Tetramethylbenzene Explicit name for Durene. 

Figure 6.18 of Xiao et al. [9] shows the FTIR spectra of 6FDA-Durene-p-intA copolymer. Three IR bands at 1780, 1720 and 1370 cm characteristic to poly-imides (Pis) are found in all polymer samples. The Pis containing p-intA revealed the IR bands in 1430-1590 cmregion due to aromatic C=C stretching vibrations. The intensity of these bands increases when aromatic rings are conjugated with C=C or C=C. 

Shao, L., Chung, T.-S., and Pramoda, K. P. (2005). The evolution of physiochemical and transport properties of 6FDA-durene toward carhon membranes from polymer, intermediate to carbon. Microporous Mesoporous Mater. 84, 59-68. 

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