M-phenylene

In the case of NBR-nylon blends it was reported that the addition of the curative m-phenylene-bis-male-imide, improved the strength and stiffness of the blend. An attempt to compare the effect of different curative... 

B. m-Phenylene-diisocyanate, toluenediisocyanate. xylenediisocya-nate, butylated hydroxytoluene, 5-chlorotoluenediisocyanate, and methylene-bis-(4-cyclohexylisocyanate)... 

Salts and Additive Compounds. Monoperchlorate. Cg HgN2 +HCIO4 color crysts can be prepd by treating m-phenylene-diamine with perchloric acid. Explds when heated to about 250°, or on impact. It is less sensitive to mechanical action than the diper-chlorate... 

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. 

Maleimides Alkyl and aryl maleimides in small concentrations, e.g., 5-10 wt% significantly enhance yield of cross-link for y-irradiated (in vacuo) NR, cw-l,4-polyisoprene, poly(styrene-co-butadiene) rubber, and polychloroprene rubber. A-phenyhnaleimide and m-phenylene dimaleimide have been found to be most effective. The solubihty of the maleimides in the polymer matrix, reactivity of the double bond and the influence of substituent groups also affect the cross-fink promoting ability of these promoters [82]. The mechanism for the cross-link promotion of maleimides is considered to be the copolymerization of the rubber via its unsaturations with the maleimide molecules initiated by radicals and, in particular, by allyfic radicals produced during the radiolysis of the elastomer. Maleimides have also been found to increase the rate of cross-linking in saturated polymers like PE and poly vinylacetate [33]. 

Peroxyacetic acid, >43% and with >6% hydrogen peroxide m-Phenylene diaminediperchlorate (dry)... 

Figure 19. Left) l,3-Dichloro-5-(l-adamantyl)benzene monomer and (Right) adamantyl-substituted poly(m-phenylene), which is shown to have a high degree of polymerization and stability, decomposing at high temperatures of around 350 °C. Taken from Ref [89] with permission.

On the other hand, numerous examples are already known in which monomeric metaphosphoric esters are generated by thermolysis reactions. Most worthy of mention in this context is the gas phase pyrolysis of the cyclic phosphonate 150 which leads via a retro-Diels-Alder reaction to butadiene and monomeric methyl metaphosphate (151) 108,109, no). While most of the phosphorus appears as pyrophosphate and trimeric and polymeric metaphosphate, a low percentage (<5%) of products 152 and 153 is also found on condensation of the pyrolyzate in a cold trap containing diethylaniline or N,N,N, N,-tetraethyl-m-phenylene-diamine. The... 

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 ... 

Apolar m-phenylene ethynylene oligomers 77 fold in apolar solvents, such as alkanes, into helices.117 Due to the strongly favored arene-arene interactions in this solvent type, the folding into a helical oligomer coincides with stacking of the folded oligomers into helical columnar polymers and a strong... 

Very recently, Liang et al. [198] reported the first poly(m-phenylene vinylene) homopolymer 168. Due to all-meta-linking of the phenylene units, the PL maxima (417 nm with a shoulder at 434 nm) of 168 is further shifted in the blue region and the emission band is very narrow, which promises to deliver a pure blue-emitting PLED (although a device fabrication was not yet reported). 

It is interesting that statistical copolymers 343, containing m-phenylene linkages that are supposed to interrupt conjugation, showed a PL maximum of 475 nm, similar to 342. Due to efficient energy transfer from the meta- to the para-linked chromophores, the emission maxima did not depend on the ratio of m- and p-divinylbenzenes, unless 100% loading of the meta units was used [420] (Scheme 2.54). 

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