M-phenylene isophthalamide

Example 17. Poly(m-phenylene isophthalamide) in solution.14 To a well-dried 250-mL four-necked straight-wall flange flask with nitrogen inlet/outlet, dropping funnel, and magnetic stirrer (Fig. 3.18a). 2.163 g of 1,3-phenylenediamine, 5.62 g of triethylamine, 5.506 g of triethylamine hydrochloride, and 36 mL of dry chloroform are added. Isophthaloyl chloride (4.06 g) in 14 mL of chloroform is then added through the dropping funnel over a 15-min period at 30° C with slow... 

Poly(phenyleneethynylene)s, 482 optically active, 516-517 synthesis of, 496-500, 502 Poly(m-phenylene isophthalamide), 136 synthesis of, 185-186 Poly(l,4-phenylene terephthalate) liquid crystalline polymers, 51 Poly(para-phenylene)s, 472. See also Poly (p -pheny lene)... 

Synthesis and mechanical and morphological characterization of (AB)n, ABA and BAB type copolymers of m-phenylene-isophthalamide and polydimethylsiloxane have been reported241 242>. The effect of copolymer type, chemical composition and segment molecular weights on phase separation and the solution behavior of these systems have also been discussed. 

The photodegradation of synthetic polymers can be prohibited (or at least reduced) upon addition of UV-stabilizers. These compounds transform the absorbed light energy into thermal energy thus preventing all sorts of photochemically initiated reactions. Films of poly-(m-phenylene-isophthalamide) were used which contained appropriate amounts of UV-stabilizers of the 2-(2 -hydroxy-5 -methylphenyl)benzotriazole type or their 21-methoxy derivatives. The following results were obtained ... 

Mw of 73 000 (Scheme 55) [229]. Colquhoun and coworkers also reported a ring-chain interconversion system in poly(m-phenylene isophthalamide) (Nomex) [230]. Cyclodepolymerization was best achieved by treating a solution of the polymer in DMSO containing CaCl2 or IiCl as a solubilizing... 

Applying this method to aromatic polymers listed in Table 9, assuming that (31 = 02 and using as a standard for comparison poly(m-phenylene isophthalamide) for which A = 47 A (from hydrodynamic data in Table 3) the values of A given in the last column of Table 9 can be obtained. These values are in reasonable agreement with the values of A in the same Table. 

If one of these structural conditions is not fulfilled, the molecule loses its unique properties. This is exemplified byTV-methyl substituted poly(p-phenylene terephthalamide) Its equilibrium rigidity (Table 10) is 20 times lower than that of the unsubstituted analog (Table 9) and approaches that of poly(m-phenylene isophthalamide). Probably, in this ase, the coplanar rrans-structure of the amide group is distorted by steric interactions of the pendant methyl group as in poly(alkyl iso-cyanate)s. 

About half of the benzene produced as a chemical feedstock is for styrene production, followed by large fractions for phenol and cyclohexane-based products. As much as half of the toluene produced is converted to benzene, depending on the price and demand differential. The largest use of toluene itself is as a component of gasoline. Much smaller amounts are used as a solvent, or in the manufacture of dinitrotoluene and trinitrotoluene for military applications. Xylenes are also used in gasoline formulations and function as octane improvers like toluene. para-Xylene and o-xylene are the dominant isomers of value as chemical feedstocks, for the production of terephthalic acid (and dimethyl terephthalate) and phthalic anhydride, respectively. Polyester and the synthetic resin markets, in turn, are major consumers of these products. meto-Xylene is oxidized on a much smaller scale to produce isophthalic acid, of value in the polyurethane and Nomex aramid (poly(m-phenylene isophthalamide)) technologies. 

Nomex aramid, made from m-phenylenediamine and isophthaloyl chloride, produces poly(m-phenylene isophthalamide) with a melting point of 380-390°C, and substantially avoided the problems of high-monomer cost (Eq. 21.17) [23]. 

Many solid-state NMR studies of oriented polymer fibers or film other than silk have been described. Orientation-dependent chemical shielding tensors especially serve as probes with which the relative orientations of specific bond vectors can be determined [10]. This analytical method can be applied to obtain structural information from oriented polyamide fibers such as poly (p-phenylene terephthalamide) (PPTA) [11], poly(m-phenylene isophthalamide) (PMIA) and poly(4-methyl-m-phenylene terephthalamide) (P4M-MPTA) fibers without isotope labeling of the samples [12] (Chapter 12). Oriented carbonyl carbon labeled poly (ethylene terephthalate) (PET) films have also been analyzed with this method [13] (Chapter 14). Especially, more quantitative structural information will be obtained for a locally ordered domain which has been recognized as an amorphous domain in X-ray diffraction analysis in heterogeneous polymer samples. 

In this chapter, therefore, some examples of the structural and dynamic analyses performed for polyamides such as nylon 4, 6, 7, 11 and 66, will be described including the oriented fibers of aromatic polyamides, poly(m-phenylene isophthalamide) (PMIA) and poly(4-methyl-m-phenylene tereph-thalamide) (P4-MPTA). 

Poly(m-phenylene isophthalamide) 660 to 700 Poly(m-xylylene adipamide) 518... 

It is now well established that certain aromatic polyamides form ordered complexes with their solvents (i.e., crystal solvates). A summary of the occurrence of these crystal solvates h s been compiled in a recent review article by lovleva and Papkov. Among the crystal solvates that have been identified jre poly(m-phenylene isophthalamide) with N-methyl-pyrrolidone and with hex methylphosphortriamide poly(p-benz-amide) with sulfuric acid and poly(p-phenylene terephthalamide) (PPTA) with sulfuric acid and with hexamethylphosphortriamide. These solvates are all characterized by a discrete melting point and a crystalline diffraction pattern. 

Poly(m-phenylene isophthalamide) and other aramids have been proposed as precursor for activated carbon materials. These materials exhibit a very homogeneous nucropore size. This property makes them usable as adsorbents, molecular sieves, catalysts or electrodes. 

Poly(m-phenylene isophthalamide) derived carbon fibers can be activated by carbon vapor deposition of benzene. The activated carbon fibers are suitable as molecular sieves for air separation. Carbon fibers can be obtained from the aramid by pyrolysis at 750-850°C. The pyrolysis may take place in Ar or CO2. 

Poly [ 1,4-phenylene-1,2-di(4-benzyloxyphenyl)vinylene], 42 Poly(phenylene ether), 139 Poly(1,4-phenylene ether sulfone), 250, 256 Poly(p-phenylene ethylene), 69 Poly(l,4-phenylene ethynylene), 105 Poly(p-phenylene ethynylene), 89 Poly(m-phenylene isophthalamide), 439 Poly(p-phenylene methylene), 69... 

Nylon 6,6 copolymer Poly(p-benzamide) Poly(m-phenylene isophthalamide)... 

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