Cyano poly

DCZP/poly(ll-(4-cyano-4 -biphenyl)-l-undecano yl acrylate 10-" ate X 10" v/cm 60... 

Properties have been determined for a series of block copolymers based on poly[3,3-bis(ethoxymethyl)oxetane] and poly [3,3-bis(methoxymethyl)oxetane]- (9-tetrahydrofuran. The block copolymers had properties suggestive of a thermoplastic elastomer (308). POX was a good main chain for a weU-developed smectic Hquid crystalline state when cyano- or fluorine-substituted biphenyls were used as mesogenic groups attached through a four-methylene spacer (309,310). Other side-chain Hquid crystalline polyoxetanes were observed with a spacer-separated azo moiety (311) and with laterally attached mesogenic groups (312). 

Generation of radicals by redox reactions has also been applied for synthesizing block copolymers. As was mentioned in Section II. D. (see Scheme 23), Ce(IV) is able to form radical sites in hydroxyl-terminated compounds. Thus, Erim et al. [116] produced a hydroxyl-terminated poly(acrylamid) by thermal polymerization using 4,4-azobis(4-cyano pentanol). The polymer formed was in a second step treated with ceric (IV) ammonium nitrate, hence generating oxygen centered radicals capable of starting a second free radical polymeriza-... 

Figure 9-1. Materials overview a few sclcclcd conjugated polymers and Ihcir properties have been compiled and ihe following abbreviations arc used DO-PPP...Poly(2-decyloxy-l,4-phcnylcnc), EHO-PPP...Poly(2-(2 -elhylliexyloxy)-l,4-phcnylenc), CN-PPP... Poly(2-(6 -cyano-6 -incthyl-licplyloxy)-l,4-phcnylene), m-LPPP... methyl-substituted ladder-type Poly( 1,4-phenylcne), and PLQY=phololuinincs-ecncc quanluni yield.

Knoevenagel-type condensation of 1,4-xylylene dinitriles and aromatic dialdehydes gives access to cyano-containing poly(para-phenylene-cyanovinylene)s (74). The insoluble parent systems (74a R, R = H) have been reported by... 

Horhold et al. and Lenz et al. [94,95]. The polycondensation provides the cyano-PPVs as insoluble, intractable powders. Holmes et al. [96], and later on Rikken et al. [97], described a new family of soluble, well-characterized 2,5-dialkyl- and 2,5-dialkoxy-substituted poly(pflrfl-phenylene-cyanovinylene)s (74b) synthesized by Knoevenagel condensation-polymerization of the corresponding alkyl-or alkoxy-substituted aromatic monomers. Careful control of the reaction conditions (tetra-n-butyl ammonium hydroxide as base) is required to avoid Michael-type addition. 

The first chiral phases introduced for gas chromatography were either amino acid esters, dipeptide, diamide or carbonyl-bis(amino acid ester) phases [721,724,756-758]. In general, these phases exhitdted poor thermal stability and are infrequently used today. Real interest and progress in chiral separations resulted from the preparation of diamide phases grafted onto a polysiloxane backbone. These phases were thermally stable and could be used to prepare efficient open tubular columns [734,756,758-762]. These phases are prepared from commercially available poly(cyano-propylmethyldimethylsiloxanes) or poly (cyanopropylmethylphenyl-... 

Although open tubular columns have been used for RPLC,42 most applications use packed columns. The most widely used column packings are formed by chemically bonding butyl (C4), octyl (C8), or octadecyl (C18) chains to a silica surface. Phenyl (Ph), cyano (CN), and amino (NH2) functionalities are also used. Polymeric packings which are finding broad acceptance include alkyl-grafted poly(methylmethacrylate) and alkyl-grafted or unmodified... 

Poly[oxy-1,4-phenylene-(1 -methylethylldene)-l, 4 -phenylene-oxy-(2"-cyano)-l",3"-phenylene], 20, was prepared from bisphenol-A and 2,6-dichlorobenzonitrile according to the precedure of McGrath et al.21... 

Reduction of Poly(2-cyano-l,3-phenylene arylene ether), 20 Twenty-five mL of a 1.0 M solution of lithium aluminum hydride (LAH) in THF was cooled to 0° C before adding a solution of 1.64 g (5.0 meg) of 20 in 120 mL of THF. The resultant slurry was stirred for 24 h at 0° C, refluxed for 1 h, recooled to 5° C, and the excess LAH decomposed with 2 mL of water. The volume of the solution was reduced to 25 mL before pouring the mixture into 500 mL of 5% HC1 to dissociate the amine aluminum salt complex and precipitate the polymer. The polymer was recovered by filtration, reslurried in 20 mL of water and the pH adjusted to 9.0 with NaOH. After recovery of the neutralized polymer was recovered, it was dried in vacuo redissolved in CHC13, and reprecipitated using water as the nonsolvent. Final drying in vacuo for 24 h at 35° C left 1.2 g (72.3%) of poly[oxy-l,4-phenylene-(l-methylethylidene)-l, 4 -phenylene-oxy-(2"-aminomethyl)-l",3"-phenylene], 21, [n] (CHCI3) 0.3 dl/g. 

The most interesting aminomethyl derivative of condensation polymers that we have prepared to date Is derived from direct reduction of poly(2-cyano-l,3-phenylene arylene ether), 20. Enchainment of benzonitrile repeat units Is accomplished by coupling 2,6-dichlorobenzonitrile with the potassium salt of bisphenol-A copolymers with lower nitrile contents can be produced by copolycondensation of bisphenol-A, 2,6-dichlorobenzonitrile and 4,4 -dichlorodiphenyl sulfone.21 The pendent nitrile function provides an active site for further elaboration. 

J. Liao and Q. Wang, Ruthenium-catalyzed Knoevenagel condensation a new route toward cyano-substituted poly(p-phenylene vinylene)s, Macromolecules, 37 7061-7063, 2004. 

J.A. Mikroyannidis and J.K. Spiliopoulos, Synthesis and optical properties of novel blue-light emitting poly(p-phenylene vinylene) derivatives with pendant oxadiazole and cyano groups, J. Polym. Sci., Part A Polym. Chem., 42 1768-1778, 2004. 

As part of an effort to develop high-performance, high-temperature-resistant polymers for microelectronics applications, we also recently described a series of both partially fluorinated and nonfluorinated poly(aryl ether ketone)s containing amide, amide-imide, cyano oxadizole, or pyridazine groups and characterized their thermal and electrical properties.11... 

The kinetics and mechanism for oxygen transfer between 4-cyano-V,V,-dimethylaniline V-oxide and a C2-capped mexo-tetraphenylporphyrinatoiron(III) and mc5 o-tetrakis(pentafiuorophenyl)-porphyrinatoiron(III) have been established. Addition of a copper(II) porphyrin cap to an iron(II)-porphyrin complex has the expected effect of reducing both the affinities and rate constants for addition of dioxygen or carbon monoxide. These systems were studied for tetradecyl-substituted derivatives solubilized by surfactants such as poly(ethylene oxide) octaphenyl ether. ... 

Attempts to dope organic semiconductors have been made very early in the field, motivated by the prospect of possibly reaching metallic conductivities [108, 109]. These synthetic metals, however, have not been realized. While p-type doping could be obtained, for example, with iodine gases for poly-p-phenylene vinylene (PPV) derivatives, and n-type doping was demonstrated with sodium for a cyano-derivative of PPV, the doping levels obtained were not stable with time. The dopant molecules readily diffused into the organic semiconductor, yet also out of it. Due to the lack of stability, these approaches were not suitable for commercial applications. 

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