Preparation of poly(alkylvinylether)s for nonlinear optical applications

Summary 3,5-Dimethoxy-4-(2-vinyloxyethoxy)-4-nitrostilbene 2 and 3,5-dimethoxy-4-(2-vinyloxyethoxy)-2,4-dinitrostilbene 5 were prepared by the reactions of 2-iodoethyl vinyl ether with 3,5-dimethoxy-4-hydroxy-4-dinitrostilbene 1 and 3,5-dimethoxy-4-hydroxy-2,4-dinitrostilbene 4, respectively. Monomers 2 and 5 were polymerized with cationic initiators to obtain polymers with the NLO-phores 3,5-dimethoxy-4-oxy-4-nitrostilbene and 3,5-dimethoxy-4-oxy-2,4-nitrostilbene in the side chain. The resulting polymer 3 and 6 were soluble in DMSO and DMF. The inherent viscosities of polymers were in the range of 0.28–0.33 dL/g in DMSO. Polymers 3 and 6 showed good thermal stabilities in their TGA thermograms, and the T_g values from DSC thermograms were in the range of 81–87°C.     

Photochromic polymers

Summary Two soluble photochromic polymers containing 1-(ß-hydroxyethyl)-3,3-dimethyl-6-nitrospiro[2H-1-benzopyran-2,2-indoline] bound on a variously long side chain were prepared. It was found that the discolouration process depends on the length of the side chain to which the photochromic centre is bound.     

Synthesis and polymerization of 2-(β-N-3′-halogencarbazolylethyl)-2-oxazolines

Summary The synthesis of three novel oxazoline monomers,all of which contain 3-halogen substituted carbazolyl groups [i.e., 2-(-N-3 chlorocarbazolylethyl)-2-oxazoline, 2-(-N-3 bromocarbazolylethyl)-2-oxazoline and 2-(-N-3 iodocarbazolylethyl)-2-oxazoline]and their polymerization is described.     

The electrochemical properties of polyaniline derivatives: poly(4,4′-diphenylamine methylenes) and poly(4,4′-diphenylimine methines)

Summary The electrochemical properties of poly(4,4-diphenylamine methylenes) and poly(4,4-diphenylimine methines) were investigated by cyclic voltammetry. A dehydrogenation reaction occured when poly(4,4-diphenylamine methylenes) underwent a electrochemical reaction and transformed to poly(4,4-diphenylimine methines). The fully oxidized poly(4,4-diphenylimine methines) had the electrochemical band gaps of 1.60–1.72 eV, which were found to significantly smaller than those of the fully reduced poly(4,4-diphenylamine methylenes).     

Condensation polymerization of α,α′-dimethoxycarbonyl-p-xylylenedicyanide (α,α’) and oxidation to a quinodimethane polymer

Summary , -di(methoxycarbonyl)-p-xylylenedicyanide and oxydiethanol were treated with Ti(OBu)₄ to produce a linear soluble polyester. Long reaction times led to the formation of an insoluble cross-linked polymer by reaction of the cyano groups.Treatment of the soluble polyester with N-cholrosuccinimide and Et₃N resulted in oxidation to a quinodimethane polymer.     

Synthesis of soluble polyarylenes containing alternating 4,4′-(1,1′-binaphthyl) and 4,4′-(3,3′-diphenyl)biphenyl structural units

Summary The synthesis and Ni(0) catalyzed homocoupling polymerization of 4,4-bis[5-(trifluoromethanesulfonyloxy)-2-biphenylyl]-1, 1-binaphthyl (9) are described. This polymerization reaction produces a soluble polyarylene containing alternating 4,4-(1,1-binaphthyl) and 4,4-(3,3-diphenyl)biphenyl structural units.     

Shape-selective isopropylation of biphenyl over a highly dealuminated mordenite: effect of propylene pressure

A highly dealuminated H-mordenite (H-M) catalyzed the selective isopropylation of biphenyl to 4,4-diisopropylbiphenyl (4,4-DIPB). The high selectivity is ascribed to the shape-selective catalysis in mordenite pores. The selectivity of 4,4-DIPB decreased during the isopropylation of biphenyl due to isomerization of 4,4-DIPB under low propylene pressure. The increase of propylene pressure suppressed the isomerization in the isopropylation. 4,4-DIPB itself was isomerized over highly dealuminated H-M under low propylene pressure.     

Shape-Selective Alkylation of Biphenyl over H-[Al]-SSZ-31 with Propylene

Isopropylation of biphenyl (BP) over [Al]-SSZ-31, a large-pore, one-dimensional zeolite has been studied. Effects of temperature, pressure and SiO₂/Al₂O₃ ratio were examined. SSZ-31 was found to be an active catalyst in the isopropylation of biphenyl with propylene. The selectivity for 4-isopropylbiphenyl (4-IPBP) and 4,4-diisopropylbiphenyl (4,4-DIPB) was high among isopropylbiphenyl (IPBP) and diisopropylbiphenyl (DIPB) isomers, respectively, indicating SSZ-31 shows shape-selective catalysis. The selectivity for 4,4-DIPB decreased with temperature increase; correspondingly the selectivity for thermodynamically more stable isomers (3,3- and 3,4 DIPB) increased with temperature. The yield of IPBP isomers decreased while that of DIPB isomers increased with temperature increase. Pressure showed less effect on conversion; however, increase in pressure suppresses the isomerization of 4,4-DIPB to 3,3- and 3,4-DIPB. Conversion decreased with increase in SiO₂/Al₂O₃ ratio. At low SiO₂/Al₂O₃ ratio of 136, relatively high triisopropylbiphenyl (TriIPB) isomers were formed in bulk products and their amount decreased with increase in SiO₂/Al₂O₃ ratio.     

Synthesis and characterization of poly(1-sila-cis-pent-3-enes) substituted with pendant pyridinyl groups

Poly[1-methyl-1-[3-(3-pyridinyl)propyl]-1-sila-cis-pent-3-ene], poly[1-phenyl-1-[3-(3-pyridinyl)propyl)-1-sila-cis-pent-3-ene], and poly[1-phenyl-1-(4-pyridinyl)-1-sila-cis-pent-3-ene] were synthesized by the anionic ring-opening polymerization of 1-methyl-1-[3-(3-pyridinyl)propyl]-1-silacyclopent-3-ene, 1-phenyl-1-[3-(3-pyridinyl)propyl]-1-silacyclopent-3-ene, and 1-phenyl-1-(4-pyridinyl)-1-silacyclopent-3-ene, respectively. These are the first polycarbosilanes which contain heterocyclic pyridine units as side-chain substituents. These polymers were characterized by¹H,¹³C, and²⁹Si NMR as well as by IR and UV spectroscopy. The molecular weight distributions were determined by gel permeation chromatography, glass transition temperatures, by differential seanning calorimetry: (DSC) and thermal behavior, by thermogravimetric analysis. (TGA).     

The photochromism of nitrospiropyran included in γ-cyclodextrin

Summary The inclusion compounds of 1, 3, 3-trimethyl-6-nitrospiro-[2H, 1-benzo-pyran-2, 2-indoline] (NSP) with -cyclodextrin (-CD), 2,3,6,0-permethylated -CD (-MCD), and naphthyl modified -CD (-NCD) showed normal photochromism in the solid state with high light sensitivity comparable with that of NSP dispersed in polymer matrices. This is in sharp contrast with NSP in the crystalline state, which is much less photosensitive. These results suggest that the host cavity offers a sufficient free volume for phototransformation of the guest molecule. The colored form of the inclusion compounds were found to be more stable both chemically upon prolonged UV irradiation and thermally in the dark as compared with that in a PMMA film.     

Dynamic mechanical properties of crosslinked polyisoprene under deformation

Summary Molecular motions of elastomers under deformations were observed through dynamic mechanical measurements. Composite master curves of dynamic moduli E and E and loss tangent tan over a wide range of frequency and in a state of elongation were obtained by the time-temperature superposition procedure. It is found that both moduli increase with strain, . The slope of the dispersion curve of E become more gradual with the increase in , while that of E is almost unchanged. The increment of E is generally larger than that of E, which does not agree with the N. W. Tschoegl prediction, E ^* ()=f() E _o ^* (), where E ^* () and E _o ^* () are complex moduli at the strain of and O, respectively, and f() is the function of only . The difference in the strain dependence of E from E was found to correspond to the strain dependence of the equilibrium modulus.     

Chemical modification of copoly(methylsilylene/1,4-phenylene) by Pt-catalyzed hydrosilation reactions with functionally substituted alkenes

Copoly(methyl-3-biphenoxypropylsilylene 1,4-phenylene), copoly(methyl-3-cyanopropylsilylene 1,4-phenylene), copoly(methyl-3-ethoxypropylsilylene 1,4-phenylene), copoly(methyl-3-phenoxypropylsilylene 1,4-phenylene), and copoly(methyl-4,7,10,13-tetraoxatetradecanylsilylene 1,4-phenylene) have been prepared by platinum-catalyzed hydrosilation graft reactions between poly (methylsilylene 1,4-phenylene) and appropriate functionally substituted alkenes. These polymers have been characterized by¹H,¹³C, and²⁹Si NMR as well as by FT-IR and UV-vis spectroscopy. The molecular weight distribution of these polymers has been determined by gel permeation chromatography (GPC), and their glass transition temperatures (T _e) by DSC.     

Preparation of Linear π-Conjugated Coordination Polymers Having Ruthenium(II) Complex in the Main Chain

Soluble -conjugated coordination polymers having a ruthenium(II) complex in the main chain were prepared from a soluble metal complex monomer and a bridging ligand via coordination. Refluxing of an ethanol-water suspension containing (4,4-dinonyl-2,2-bipyridyl)Ru(III) with 2,3-bis(2-pyridyl)pyrazine gave the coordination polymer. The resulting polymer was soluble in common organic solvents. The structure was confirmed by uv/vis spectra and gpc analysis.     

Synthesis and thermal properties of block copolyetheresters with poly(pentamethylene p,p′-bibenzoate) segments

The block copolyetheresters with hard segments of poly(pentamethylene p,p-bibenzoate) and soft segments of poly (tetramethylene ether) were prepared by melt polycondensation of dimethyl-p,p-bibenzoate, 1,5-pentanediol and poly (tetramethyene ether) glycol (PTMEG) with molecular weights of 650, 1000 and 2000. The results by NMR indicate that the polymer composition is determined by the charge molar ratio (x) of PTMEG to dimethyl-p,p-bibenzoate. The thermal transitions of the block copolyetheresters were investigated by DSC in combination with X-ray diffraction and polarized microscopy. Some block copolyetheresters exhibit a monotropic smectic phase due to the presence of the poly (pentamethylene p,p-bibenzoate) segments. As the molar content of PTMEG increases, the average sequence length of the polyester segments decreases, the isotropic-smectic transition temperature and the smectic order decrease accordingly. When x is as high as 0.3, the block copolyetheresters exhibit no liquid crystallinity.     

Preparation of copolymer of styrene with hemin and its functional property as cyanide ion exchanger

Summary Copolymers of hemin and styrene with different hemin contents were prepared by radical polymerization, using pyridine as the solvent and ,-azobisisobutyronitrile as the initiator. It was found that the obtained copolymers are insoluble in aqueous solvents and have function as cyanide ion exchanger.     

Functional polymers

N-Acryl-N,N-dicyclohexylurea and N-methacryl-N,N-dicyclohexylurea have been synthesized. N-Acryl-N,N-dicyclohexylurea was polymerized with azobisisobutyronitrile as the initiator and the copolymerization of these two monomers with styrene and methyl methacrylate was also accomplished. Monomers, polymers, and copolymers were characterized.Part XXXV: O. Vogl, Polimery, in press.     

Liquid crystalline polyethers based on conformational isomerism

Summary The synthesis and characterization of copolyethers based on 1-(4-hydroxyphenyl)-2-(2-methyl-4-hydroxyphenyl)ethane (MBPE), 1,8-dibromooctane and each of the following three nonmesogenic bisphenols: 3,4-dihydroxydiphenylmethane (3,4-BPM), 4,4-isopropylidenediphenol (4,4-BPA) and 3,4-isopropylidenediphenol (3,4-BPA) are presented. Copolymers based on MBPE, 3,4-BPM and 1,8-dibromooctane display a nematic mesophase up to compositions containing as much as 70 mol% of 3,4-BPM. The range of mesomorphism decreases on going from 3,4-BPM to 3,4-BPA and to 4,4-BPA. These results demonstrate that structural units derived from parent amorphous and liquid crystalline homopolymers can be isomorphous within the mesophase over a certain range of copolymer composition of the resulting copolymers. Subsequently, the parameters of the mesomorphic phase transitions of these copolymers represent weight averaged values of the corresponding parameters of the parent homopolymers.Part 12: V. Percec and Y. Tsuda, Polymer submitted     

Female-produced oviposition deterrents of the cigarette beetle,Lasioderma serricorne (F.) (Coleoptera: Anobiidae)

Oviposition deterrents of the cigarette beetle,Lasioderma serricorne, were isolated from its adult body extract and found to be identical to (2S,3R,1'S)-2,3-dihydro-3,5-dimethyl-2-ethyl-6-(l-methyl-2-oxobutyl)-4H-pyran-4-one (-serricorone) and its lR-epimer (-serricorone) by spectroscopic evidence. Serricorone was previously found as one of the minor sex pheromone components of the same insect, and hence indicating bi-functional nature. The presence of two isomers in the body was proved by careful treatment. Each of them exhibited the same level of oviposition deterring activity, which was less potent than the crude body extract at an increased concentration.     

Stegobiol,a new sex pheromone component of drugstore beetle (Stegobium paniceum L.)

New sex pheromone component of femaleStegobium paniceum L. was isolated and identified as 2,3-dihydro-2,3,5-trimethyI-6-(1-methyl-2-hydroxybutyl)-4H-pyran-4-one, stegobiol, by spectral data and chemical conversion from stegobinone. Relative configuration at C-2, C-3, and C-1 was determined as 2S,3R,1S by the conversion from (2S,3R,1R)-stegobinone. This new sex pheromone elicits the pheromonal response from the species.     

Glass transition temperature — molecular weight relation of a poly(amide-imide)

Summary Several fractions of a poly(amide-imide), prepared from 3,4-dicarboxy-4-chloroformyl biphenyl anhydride and 4,4-methylene dianiline, were studied in order to determine the Tg and K values of Fox-Flory relationship.