Bal Jung

Polymerization of α-hydroxyacetylenes by transition metal catalysts

Abstract α-Hydroxyacetylenes (2-propyn-1-ol, DL-3-butyn-2-ol, 1-octyn-3-ol, 2-phenyl-3-butyn-2-ol) with a hydroxy functional group were polymerized by various Mo- and W-based catalysts. In general, the catalytic activities of Mo-based catalysts were greater than those of W-based catalysts for these polymerizations. In the polymerization of 2-propyn-l-ol, MoCl5 alone and the MoCl5-EtAlCl2 catalyst system gave a quantitative yield of polymer. In the polymerization of 2-propyn-l-ol and its homologues by Mo-based catalysts, the polymer yield decreased as the bulkiness of the substituent increased. On the other hand, the polymer yield increased as the bulkiness of the substituent increased in WCl6-EtAlCl2-catalyzed polymerization. Polymers with a bulkier substituent showed better solubility in organic solvents than those without a substituent [e.g., poly (2-propyn-l-ol)]. The structures of the resulting polymers were characterized by various instrumental methods such as 1H- and 13C-NMR, IR, and UV-visible spec...

Polymerization of tripropargylamine by transition metal catalysts and molecular structure of poly(tripropargylamine)

Abstract A novel highly conjugated polymer with two cyclic recurring units per monomeric unit was prepared from tripropargylamine using various transition metal catalysts. PdCl 2 , PtCl 2 , and RuCl 3 were found to be effective catalysts, whereas the tungsten-based and molybdenum-based catalysts gave a low yield of polymer. In the polymerization by PdCl 2 , DMF, DMSO, and pyridine were found to be good solvents. The resulting polymers were brown or black powders and mostly insoluble in organic solvents regardless of the polymerization conditions and the catalysts used. The solid-state 13 C-NMR spectrum of poly(tripropargylamine) showed the carbon peaks of the conjugated double bond on the polymer backbone at 110–150 ppm, which had been absent in the monomer. The chemical structure of polymer had a quasi-helical characteristic (TG 3 ). The calculated identity period was 11.97 A. Furthermore, this polymer possessed less than a three-dimensional order with a noncrystalline morphology.

Polymerization of Cyclohexene Oxide By Organoaluminum Compounds

Abstract The polymerization of cyclohexene oxide (CHO) by various organoaluminum compounds such as R3Al (R = Me, Et, i-Bu), Et2AlCl, and EtAlCl2 is reported. Ethyl-substituted aluminum compounds were found to be very effective for this polymerization. As more chlorine atom is substituted on the aluminum atom, the polymer yield was increased though the molecular weight was decreased. The polymer yields at varying monomer-to-catalyst mole ratios (M/C) were similar (80–93%). The temperature and solvent effect for the present polymerization were also studied. The present poly(CHO) was a less stereoregular (atactic) isomer, regardless of catalysts and polymerization conditions. The resulting poly(CHO) was a white powder ad was soluble in aromatic and halogenated hydrocarbon solvents such as benzene, chlorobenzene, CCl4, chloroform, etc.

Synthesis and properties of conducting polymers from propargylammonium salts by transition metal catalysts

Summary form only given. Novel conjugated ionic polymers from propargylamonium bromides were synthesized and characterized. The ionic monomers used are as follows: HC/spl equiv/CCH/sub 2//sup +/NH/sub 3/Br/sup -/, HC/spl equiv/CCH/sub 2//sup +/N(CH/sub 3/)2(CH/sub 2/Ph)Br/sup -/, (HC/spl equiv/CCH/sub 2/)/sup 2//sup +/NH2Br/sup -/. These monomers were easily polymerized by PdCl/sub 2/ and PtCl/sub 2/ to give a high yield of polymer. In most cases, the catalytic activity of Mo-based catalysts was found to be greater than that of W-based catalysts. The infrared spectra of the resulting conjugated ionic polymers showed neither the acetylenic /spl equiv/C-H stretching nor the C/spl equiv/C stretching frequencies. Instead the conjugated double bond stretching frequency of polymer backbone was newly oberserved at about 1630cm/sup -1/. The resulting polymers were mostly insoluble in organic solvents, and brown or black powder. The electrical conductivities of iodine-doped ionic polymers increased with doping time and reached the value of 10/sup -3//spl tilde/10/sup -2/spl Omega//sup -1/cm/sup -1/. The thermal and morphological properties of the conjugated ionic polymers were also studied.

The effect of styrene on epoxy resin formulations for filament winding

Abstract The effect of styrene on epoxy resin formulations for filament winding were studied from the viewpoints of processing, mechanical, and thermal properties. Five epoxy blends with different compositions of epoxy resin, hardener, and styrene were made and evaluated. The addition of a small amount (maximum 10%) of styrene to the epoxy formulations decreased the resin viscosity from 605 to 160 cP and increased the pot life of the mixed resin system. The tensile and flexural properties were found to be similar, regardless of styrene content. The thermal properties (heat deflection temperature, glass transition temperature, etc.) of the resulting thermoset blends decreased as the styrene content increased. From the viewpoints of resin viscosity, pot life, and mechanical and thermal properties, it was found that the addition of a small amount (5–10%) of styrene to an epoxy resin was adequate for an epoxy matrix system used for filament winding.