Phenyl substituted poly

DM Johansson, G Srdanov, G Yu, M Theander, O Inganas, and MR Andersson, Synthesis and characterization of highly soluble phenyl-substituted poly(p-phenylenevinylenes), Macromolecules, 33 2525-2529, 2000. 

D.M. Johansson, M. Theander, G. Srdanov, G. Yu, O. Inganas, and M.R. Andersson, Influence of polymerization temperature on molecular weight, photoluminescence, and electroluminescence for a phenyl-substituted poly(p-phenylene vinylenes), Macromolecules, 34 3716-3719, 2001. 

Later researchers followed essentially the same process, substituting monomer precursors instead of the dimer, to produce PPV films. " The monomers were evaporated and the vapors carried into the pyrolysis chamber, where they were pyrolyzed at 800°C. The reactant species were then transported to the substrate maintained at 60°C to form the precursor polymer film. This film was then thermally converted to PPV at 150-320°C. - Scafer et al. have further shown that PPV can be produced via the dehydrogenation route introduced by Iwatsuki et al. They showed that soluble a-phenyl substituted poly-p-xylylene can be prepared by CVP of l-a-chlorobenzyl-4-methylbenzene. The parylene was then dehydrogenated by DDQ resulting in PPV. This process could be used to produce both segmented and unsegmented PPVs. The segmentation ratio was controlled by the molar ratio of the parylene to DDQ, in the... 

Korshak and Rusanov [232] reviewed in detail the studies conducted on phenyl substituted poly-heteroarylencs. Phenyl substituted polyquinazolinones [233-236] were reported to be thermally stable up to 420°C in air and polyimidincs also showed a high thermal stability as evident from 10% weight loss in the temperature range of 400 -525°C and 450°-560°C in air and in an inert environment, whereas comparatively low thermal stability was observed in polypyrrolinones. Unsubstituted poly(l,2,4-triazine)s and polyphenyIqui-... 

R. Tang, X. Xu, C. Cheng, G. Yu, Y. Liu, and F. Xi. Synthesis and luminescence properties of novel phenyl-substituted poly(p-phenylene vinylene) derivatives. Synth. Met, 150(1) 63-71, April2005. 

D.-C. Shin, Y.-H. Kim, H. Yon, J. G. Jin, and S.-K. Kwon. Intramolecular energy transferable (2,2-diphenylvinyl)phenyl substituted poly(p-phen-ylenevinylene) derivative with efficient photoluminescence and electroluminescence. 7. Polym. Sci., Part A Polym. C/iem., 42 5636-5646, 2004. 

M. Berggren, G. Gustaffson, O. Inganas, M. R. Anderson, O. Wennerstrdm, T. Hjertberg, Thermal control of near-infrared and visible electroluminescence in alkyl-phenyl substituted poly thiophenes, Appl. Phys. Lett., 65, 1489-1491 (1994). 

A precursor route not involving heteroatoms in the precursor polymers has also been developed. It is based on the oxidation of soluble poly(/ -xylylene)s to corresponding PPVs by using stoichiometrical amounts of 2,3-dichloro-5,6-dicyano-l,4-benzochinone (DDQ) (Scheme 7) but is restricted so far to a-phenyl-substituted poly(/ -xylylene)s [36]. 

Other Precursor Metitods. The thermal eliminative ring closure of l,4-diphenyl-3-(JV,N-dimethylamino)-hex-5-en-l-yne has been shown to give terphenyl [324], By an analogous method, the poly(N,N-dimethylamino)-hex-5-en-l-yne derivative affords phenyl-substituted poly(p-phenylene)s on pyrolysis [325]. 

Sogah (24) and McGrath (25) have reported tert-butyl and phenyl-substituted poly(aryl ether ketones) respectively, which are prepared by nucleophilic substitution reaction of the corresponding substituted hydroquinones and 4,4 -difluorobenzophenone. The resulting polymers were amorphous and highly soluble in common organic solvents as a result of the bulky substituents which suppressed crystallization. The bulky substituents were cleaved with acid in a reverse Friedel-Crafts alkylation reaction to produce the semi-crystalline PEEK (24). 

Silyl radicals generated from both phenyl and n-hexyl substituted poly-(hydrosilane)s add readily to a variety of compounds containing C = C and 0 = C moieties to give the corresponding radical adducts for which EPR spectra have been recorded. ... 

These thermolysis reactions normally produce polymeric products, free of the cyclic analogs, in essentially quantitative yield and in sufficient purity to give satisfactory elemental analysis upon removal of the sHyl ether byproduct under vacuum. Final purification is generally achieved by precipitation of the polymer into a non-solvent such as hexane. With the exception of poly(diethylphosphazene) (2), which is insoluble in all common solvents (see below), the new polymers are readily soluble in CH CU and CHCU. In addition, the phenyl substituted compounds (3-6) are soluble in THF andvanous aromatic solvents. None of the polymers are water-soluble however, Me2PN]n (1) is soluble in a 50 50 water/THF mixture. 

Samples of the poly(dialkylphosphazenes) 1 and 2 displayed X-ray powder diffraction patterns characteristic of crystalline regions in the materials. The peaks in the diffraction pattern of 1 were of lower amplitude and greater angular breadth than those of 2. These data indicate that poly(diethylphosphazene) (2) is highly crystalline while poly(dimethyl-phosphazene) (1) is more amorphous with smaller crystalline zones. This high degree of crystallinity is probably responsible for the insolubility of 2 as noted above. All of the phenyl substituted polymers 3-6 were found to be quite amorphous in the X-ray diffraction studies, a result that is further evidence for an atactic structure of the poly(alkylphenylphosphazenes) 3 and 4 and for a random substitution pattern in the copolymers 5 and 6. 

Few neutron or electron diffraction studies have been reported, although the neutron structure analysis of substituted poly(benzobisthiazole) and poly(benzobisoxazole) derivatives of 19 and 5 has been reported and the torsion angle between the benzobisthiazole and phenyl rings was shown to be 7.2° larger than that determined from X-ray methods <1999MM4010, 2001MM2012>. 

However, the particular synthetic requirements in the preparation of conjugated polymers have thus far severely limited the number of similarly hierarchically structured examples. Pu et al. reported different types of conjugated polymers with fixed main-chain chirality containing binaphthyl units in their backbone which exhibited, for example, nonlinear optical activity or were used as enantioselective fluorescent sensors [42—46]. Some chirally substituted poly(thiophene)s were observed to form helical superstructures in solution [47-51], Okamoto and coworkers reported excess helicity in nonchiral, functional poly(phenyl acetylenejs upon supramolecular interactions with chiral additives, and they were able to induce a switch between unordered forms as well as helical forms with opposite helical senses [37, 52, 53]. 

In regard to substitution reactions of the functional phenyl groups, poly(diphenylsilylene-co-methylene) is a very interesting educt for the preparation of modified polycarbosilanes as precvirsors for SiC-based ceramic fibers. 

The MW of polymers of aliphatic disubstituted acetylenes such as 2-octyne remarkably reduces, when such polymers are irradiated with y-rays in airll7) (Fig. 10). In contrast, polymers of aromatic disubstituted acetylenes like 1-phenyl-1-propyne hardly degrade by y-rays irradiation in air. Thus the degradation behavior of substituted poly acetylenes is greatly dependent on the kind of substituent. The mechanism is essentially the same as that for thermal degradation. 

The relationship between structure and photoinitiation activity has been examined for polymeric systems bearing side-chain 1-substituted cyclohexyl-phenyl ketone moieties in the UV curing of the HDDA/BA equimolar mixture [19,20]. Indeed, the activity of poly[(l-acryloxycyclohexyl)phenyl ketone] [poly (APK)] and styrene/4-chloromethyl-styrene/l-(4-styrylmethyloxy)cyclohexyl phenyl ketone copolymers (PABOK) has been compared with that of the corresponding low-molecular-weight structural models such as 1-hydroxy-cyclohexyl phenyl ketone (HPK), 1-acetoxy-cyclohexyl phenyl ketone (ACPK) and l-(4-isopropyl-benzyloxy) cyclohexyl phenyl ketone (PIBOK). 

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