Home About us Contact
|
Home About us Contact | ||
|
|
||
Stable Poly (stable + poly)
Selected AbstractsStable poly(methyl methacrylate- co -divinylbenzene) microspheres via precipitation polymerizationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 6 2005Sunhye Yang Stable poly(MMA- co -DVB) microspheres were prepared by precipitation polymerization using acetonitrile as the main medium under various polymerization conditions including monomer and initiator concentrations. [source] Emulsifier-Free Emulsion Copolymerization of Vinyl Acetate and 3-Dimethyl(methacryloyloxyethyl)ammonium Propanesulfonate and Swelling Behavior of their Copolymer MatricesMACROMOLECULAR REACTION ENGINEERING, Issue 5 2007Elena Kamenska Abstract Stable poly{(vinyl acetate)- co -[3-dimethyl(methacryloyloxyethyl)ammonium propanesulfonate]} latexes with different compositions were synthesized by emulsifier-free emulsion copolymerization. An unusual "overshooting" behavior of the copolymer tablets is explained based on the formation of specific clusters of oppositely oriented dipoles. The variation of their concentration with the zwitterionic monomer unit fraction, ionic strength and temperature is responsible for the differences in the swelling kinetics established. The results show that these parameters can be used to control swelling degree of copolymer matrices and their sustained drug delivery. [source] Novel thermally stable poly(amine hydrazide)s and poly(amine-1,3,4-oxadiazole)s for luminescent and electrochromic materialsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2005Guey-Sheng Liou Abstract We describe the preparation, characterization, and luminescence of four novel electrochromic aromatic poly(amine hydrazide)s containing main-chain triphenylamine units with or without a para-substituted N,N -diphenylamino group on the pendent phenyl ring. These polymers were prepared from either 4,4,-dicarboxy-4,- N,N -diphenylaminotriphenylamine or 4,4,-dicarboxytriphenylamine and the respective aromatic dihydrazide monomers via a direct phosphorylation polycondensation reaction. All the poly(amine hydrazide)s were amorphous and readily soluble in many common organic solvents and could be solution-cast into transparent and flexible films with good mechanical properties. These poly(amine hydrazide)s exhibited strong ultraviolet,visible absorption bands at 346,348 nm in N -methyl-2-pyrrolidone (NMP) solutions. Their photoluminescence spectra in NMP solutions or as cast films showed maximum bands around 508,544 and 448,487 nm in the green and blue region for the two series of polymers. The hole-transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. All obtained poly(amine hydrazide)s and poly(amine-1,3,4-oxadiazole)s exhibited two reversible oxidation redox couples at 0.8 and 1.24 V vs. Ag/AgCl in acetonitrile solution and revealed excellent stability of electrochromic characteristics, changing color from original pale yellow to green and then to blue at electrode potentials of 0.87 and 1.24 V, respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3245,3256, 2005 [source] Fully Crosslinked Poly[cyclotriphosphazene- co -(4,4,-sulfonyldiphenol)] Microspheres via Precipitation Polymerization and Their Superior Thermal PropertiesMACROMOLECULAR REACTION ENGINEERING, Issue 1 2007Lu Zhu Abstract Fully crosslinked, stable poly[cyclotriphosphazene- co -(4,4,-sulfonyldiphenol)] (PZS) microspheres have been prepared via the polycondensation between hexachlorocyclotriphosphazene and 4,4,-sulfonyldiphenol by precipitation polymerization. The diameter of the PZS microspheres ranged from 0.6 to 1.0 µm with the specific surface area of the microspheres ranging from 11.7 to 10.1 m2,·,g,1. The formation of the non-porous microspheres was observed to obey an oligomeric species absorbing mechanism. The fully crosslinked chemical structure of the PZS microspheres were determined by IR, CP/MAS NMR, XRD, and EDX. No glass-transition temperature was observed and the onset of the thermal-degradation temperature was 542,°C. Thermal stability of the PZS microspheres by the precipitation polycondensation was significantly improved as compared with crosslinked microspheres produced by addition polymerizations. [source] Preparation and properties of new thermally stable poly(ether imide amide)sPOLYMER INTERNATIONAL, Issue 8 2004Shahram Mehdipour-Ataei Abstract 2,6-Bis(4-aminophenoxy)pyridine was prepared via reaction of 4-aminophenol with 2,6-dichloropyridine in the presence of potassium carbonate. Reaction of the diamine with two mol of trimellitic anhydride afforded a diacid with preformed imide structures. Poly(ether imide amide)s were prepared by polycondensation reactions of the diacid with different diamines in the presence of triphenyl phosphite. All the monomers and polymers were fully characterized and the physical properties of the polymers including solution viscosity, thermal stability, thermal behavior and solubility were studied. Thermal analysis data showed the polymers to have high thermal stability. Copyright © 2004 Society of Chemical Industry [source] | ||||||||||