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1Latest Papers from Table of Contents or Articles in PressR. Durst ; K. Sauls ; D. S. Peal ; A. deVlaming ; K. Toomer ; M. Leyne ; M. Salani ; M. E. Talkowski ; H. Brand ; M. Perrocheau ; C. Simpson ; C. Jett ; M. R. Stone ; F. Charles ; C. Chiang ; S. N. Lynch ; N. Bouatia-Naji ; F. N. Delling ; L. A. Freed ; C. Tribouilloy ; T. Le Tourneau ; H. LeMarec ; L. Fernandez-Friera ; J. Solis ; D. Trujillano ; S. Ossowski ; X. Estivill ; C. Dina ; P. Bruneval ; A. Chester ; J. J. Schott ; K. D. Irvine ; Y. Mao ; A. Wessels ; T. Motiwala ; M. Puceat ; Y. Tsukasaki ; D. R. Menick ; H. Kasiganesan ; X. Nie ; A. M. Broome ; K. Williams ; A. Johnson ; R. R. Markwald ; X. Jeunemaitre ; A. Hagege ; R. A. Levine ; D. J. Milan ; R. A. Norris ; S. A. Slaugenhaupt
Nature Publishing Group (NPG)
Published 2015Staff ViewPublication Date: 2015-08-11Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; Body Patterning/genetics ; Cadherins/deficiency/*genetics/*metabolism ; Cell Movement/genetics ; Chromosomes, Human, Pair 11/genetics ; Female ; Humans ; Male ; Mice ; Mitral Valve/abnormalities/embryology/pathology/surgery ; Mitral Valve Prolapse/*genetics/*pathology ; Mutation/*genetics ; Pedigree ; Phenotype ; Protein Stability ; RNA, Messenger/genetics ; Zebrafish/genetics ; Zebrafish Proteins/genetics/metabolismPublished by: -
2Articles: DFG German National LicensesPHILLIPS, GLYN O. ; BLOUIN, FLORINE A. ; ARTHUR, JETT C.
[s.l.] : Nature Publishing Group
Published 1964Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] We have examined the behaviour of a number of glycosides on y-radiation, and the G values quoted in this communication were obtained in each case from initially linear yield-dose curves. Aromatic groups forming the aglycon were found to stabilize the glycosidic group strongly towards radiation ...Type of Medium: Electronic ResourceURL: -
3Articles: DFG German National LicensesEmini, E. A. ; Schleif, W. A. ; Nunberg, J. H. ; Conley, A. J. ; Eda, Y. ; Tokiyoshi, S. ; Putney, S. D. ; Matsushrta, S. ; Cobb, K. E. ; Jett, C. M. ; Eichberg, J. W. ; Murthy, K. K.
[s.l.] : Nature Publishing Group
Published 1992Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] The antibody used for this purpose was a mouse-human IgGl chimaeric monoclonal antibody, termed C/31, which containsn the intact variable region of the previously described murine 0.5/3 monoclonal antibody. The 0.5/3 antibody is directed to the V3 loop domain of the HIV-1 Illb variant gp!20 ...Type of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesStaff View
ISSN: 1546-1696Source: Nature Archives 1869 - 2009Topics: BiologyProcess Engineering, Biotechnology, Nutrition TechnologyNotes: [Auszug] To the editor: In January's issue, the article on “USDA Sows Seeds for Its Future,” states: “According to ARS, every year the United States produces more than 100 tons of surplus raw agricultural products.” Several zeroes should be added to the “100.” For ...Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesStaff View
ISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: The preparation of radiation-induced graft polymers of cotton cellulose, while retaining the fibrous nature and high molecular weight of the cellulose, depended primarily on the radiochemical yields of cellulose reactions and of graft polymerization reactions. Yields of the initial major molecular changes in cellulosic polymer indicated that, in the case of scission of the molecule and carboxyl group formation, chain reactions were not initiated by radiation; however, in the case of carbonyl group formation chain reactions were initiated but quickly terminated. Generally, experimental procedures, used in graft polymerization reactions, were: (1) simultaneous irradiation reactions, that is, application of monomers or solutions of monomers to cellulose or chemically modified celluloses, then irradiation; and (2) post-irradiation reactions, that is, irradiation of cellulose or chemically modified celluloses, then after removal from the field of radiation, contacting the irradiated cellulose with monomer. Some of the most important factors influencing the radiochemical yields of graft polymerization reactions of styrene and acrylonitrile onto cellulose were: concentration of monomer in treating solution; solvent; ratio of monomer solution to cellulose; prior chemical modification of cellulose; and absence of oxygen, particularly in post-irradiation reactions. Experimental data were presented, and the direct and indirect effects of Co60 γ-radiation on these reactions were discussed.Additional Material: 4 Ill.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesNakamura, Yoshio ; Hinojosa, Oscar ; Arthur, Jett C.
New York, NY [u.a.] : Wiley-Blackwell
Published 1970Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: Ethyl acrylate was graft-copolymerized from acetone-water systems with γ-irradiated, purified cotton cellulose. The scavenging of the free radicals in the irradiated cellulose by water, acetone, and water-acetone systems was determined by electron spin resonance spectroscopy. The ESR spectra of free radicals, scavenged by water and acetone, were recorded by the use of a time-averaging computer attached to the ESR spectrometer, in which the ESR spectrum of the irradiated cellulose, which had been immersed in water and/or acetone, was electronically subtracted from the ESR spectrum of the irradiated cellulose control. For both water and acetone, the ESR spectra of the scavenged free radicals were singlets. This indicated that free radical sites formed on carbon C1 or C4 on radiation-initiated depolymerization, which would generate singlet ESR spectra, were readily accessible to these solvents. The maximum scavenging of the radicals was observed when irradiated cellulose was immersed in acetone-water solution which had a composition of 25/75 vol-%. The scavenging of the free radicals in irradiated cellulose when immersed in acetone-water solutions was less than when immersed in methanol-water solutions. Also, the extent of graft copolymerization of ethyl acrylate from acetone solutions with irradiated cellulose was less than that of ethyl acrylate from methanol solutions. These differences were probably due to differences in the diffusion rates of acetone and methanol into the cellulosie structure. The Trommsdorff-type effect in the acetone solutions would be less than in the methanol solutions, since acetone is a better solvent for poly(ethyl acrylate) than methanol.Additional Material: 5 Ill.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesSingh, Sujan ; Hinojosa, Oscar ; Arthur, Jett C.
New York, NY [u.a.] : Wiley-Blackwell
Published 1970Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: The substitution of 2-furoyl, 5-methyl-2-furoyl, 2-furanacryloyl, or 5-bromo-2-furoyl groups on fibrous cotton cellulose increased the radiation rsistance of cellulose, as indicated by the retention of strength of the modified fibrous cellulose at high dosages of γ-radiation compared with that of irradiated, unmodified fibrous cellulose. The presence of electropositive or electronegative substituents on the furan groups did not significantly change their radioprotective effects for cellulose. Electron spin resonance (ESR) spectra of irradiated celluloses indicated that the long-lived free radical sites were similar, if not the same, in both irradiated, unmodified, and modified celluloses. The radio protective effects of furan groups for cellulose were attributed to absorption of energy from the secondary radiations, primarily the secondary electrons, by the groups due to their π-electron-type structures. The absorption of energy by the groups apparently decreased the localization of energy on carbon C1 or C4 on the cellulose molecule which would result in depolymerization and loss in breaking strength of the fibrous cellulose. The radioprotective effects of furan groups for cellulose were similar to those of benzenoid groups.Additional Material: 1 Ill.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesArthur, Jett C. ; Baugh, Peter J. ; Hinojosa, Oscar
New York, NY [u.a.] : Wiley-Blackwell
Published 1966Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: The ESR spectra of microcrystalline cellulose and purified cotton cellulose reacted with ceric ammonium nitrate in nitric acid were determined. The effects of the concentration of ceric ion, atmosphere, temperature, and graft copolymerization with acrylonitrile on the rates of formation and decay of radicals in the cellulose molecule were determined under both static and dynamic conditions. Under static conditions, after the desired conditions of reaction, the samples were frozen at -100 or -160°C., and then the concentration of free radicals was determined. Under dynamic conditions ceric ion solution was continuously flowed through the celluloses while these determinations were being made at 25°C. In the presence of oxygen the rate of decay of free radicals was decreased. On initiation of copolymerization reactions with acrylonitrile, there was an increase in radical concentration, then a decrease. Apparently, during graft copolymerization the radical site initially on the cellulose molecule was retained on the end of the growing polymer chain. Then additional ceric ion coordinated with the hydroxyl groups of the cellulose, leading to the formation of additional radical sites. An Arrhenius interpretation of the effect of temperature on the formation of these additional radical sites gave apparent activation energies for radical formation on cotton cellulose as 34 kcal./mole and on microcrystalline cellulose as 29 kcal./mole.Additional Material: 13 Ill.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesBaugh, Peter J. ; Hinojosa, Oscar ; Arthur, Jett C. ; Mares, Trinidad
New York, NY [u.a.] : Wiley-Blackwell
Published 1968Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: The ESR spectra of complexes of fibrous cotton cellulose and cupriammonia dihydroxide or cupriethylene diamine dihydroxide under various experimental conditions were determined. The spectra of both complexes with cotton cellulose were almost identical at -100 and 25°C. The spectrum of the complex of cupriethylene diamine dihydroxide with cellulose was stable to temperatures as high as 100°C. The sum of the linewidths of the hyperfine components of the spectra for each complex was about 180 gauss. Cotton fibers were combed and aligned with their axes (lengths) parallel to the magnetic field (B∥); after formation of either of the complexes with cellulose a minumum of hyperfine structure of components centered at H∥ was observed. A maximum of hyperfine structure of these components was observed when the complexed fibers were aligned with their axes perpendicular to the magnetic field (B⊥). The opposite was true of components centered at H⊥. For a complex of cupriethylene diamine dihydroxide and cellulose at 25°C. and at high pH the g∥ was 2.2127 and the g∥ was 2.0476. It was suggested that the alignment of most of the complex was its axis of symmetry at a maximum angle to the axes of the cotton fiber, when the axes of the fibers were in the parallel alignment with the magnetic field. At high pH these observations were even more marked. When ramie was used with cupriethylene diamine dihydroxide at high pH, the contribution of components centered at H∥ to the spectra was zero. Spectra for the copper compounds alone and complexed with cellobiose are also reported.Additional Material: 16 Ill.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: A kinetic analysis of the radiation-initiated copolymerization reactions of 2-hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate (HPMA), and methacrylic acid (MAA) from water, methanol (MeOH), N,N-dimethylformamide (DMF), dimethysulfoxide (DMSO), and combinations of these solvents with irradiated fibrous cellulose I and II was made. The maximum extent of copolymerization of HEMA and HPMA with irradiated cellulose occurred from water solutions. When organic solvents were added to the water solution, while the concentration of monomer was kept constant, the extent of copolymerization decreased. The maximum extent of copolymerization of MAA with irradiated cellulose occurred from mixtures of MeOH (15-30 vol-%) and water (85-70 vol-%) solutions rather than from water. After initiation of the copolymerization reactions, they were apparently diffusion controlled and exhibited second-order kinetics. The relative concentrations of grafted polymer and homopolymer formed with irradiated cellulose from aqueous solutions depended primarily on the concentration of water in the solutions. From MeOH (60 vol-% or less)-water (40 vol-% or more) solutions, about 60% of poly(MAA) formed was apparently grafted polymer; from solutions containing less water, the fraction of grafted polymer decreased to about 40%.Additional Material: 12 Ill.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesSingh, Sujan ; Hinojosa, Oscar ; Arthur, Jett C.
New York, NY [u.a.] : Wiley-Blackwell
Published 1971Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: The substitution of 2-thenoyl, 5-methyl-2-thenoyl, 2-thiopheneacryloyl, 5-bromo-2-thenoyl, and 5-bromo-2-thiopheneacryloyl groups on fibrous cotton cellulose increased the radiation resistance of cellulose, as indicated by the retention of the breaking strengths of the modified fibrous celluloses at high dosages of γ-radiation, as compared with that of irradiated, unmodified fibrous cellulose. The presence of electropositive or electronegative substituents on the thiophene groups did not reduce the radioprotective effects of these groups for cellulose. Crosslinking of the cellulose thenoates in 1,3-di(4-pyridyl)-propane did not significantly reduce the radiation resistance of the thenoates. Examination of the ESR spectra of irradiated cellulose and cellulose thenoates indicated that the site of the long-lived free radicals on the irradiated cellulose molecules was not changed by the chemical modification. However, the concentration of long-lived free radicals in irradiated cellulose thenoates, at a given radiation dosage, was less than that in irradiated cellulose. The localization of energy on carbon C1 or C4 of the cellulose molecule, which leads to depolymerization and loss in breaking strength of fibrous cellulose, was decreased. The radioprotective effects of thiophene groups for cellulose were similar to those of furan and benzenoid groups.Additional Material: 2 Ill.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesArthur, Jett C. ; Hinojosa, Oscar ; Tripp, Verne W.
New York, NY [u.a.] : Wiley-Blackwell
Published 1969Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: The effects of crystalline modification of cellulose and of water on the ESR spectra generated by the trapped free radicals in gamma-irradiated celluloses were investigated for cotton cellulose I, II, III, and IV, partially decrystallized cotton cellulose, ballmilled cotton cellulose, hydrocelluloses of cellulose III and IV, and ramie. On irradiation of the celluloses, free radicals were formed on the cellulose molecule, probably following dehydrogenation or chain cleavage. The free radicals located within the less ordered or amorphous regions of the cellulose reacted readily with water and were terminated. The radicals located within the more ordered regions of the celluloses could be made accessible to reaction with water by the interaction of the celluloses with solvents which caused dimensional changes in the cellulosic structure. In the highly ordered regions of the celluloses, even after long periods of time in solvents which caused large dimensional changes in the cellulosic structure, the trapped free radicals were not terminated by reaction with solvent or water. The ESR spectra of the irradiated, dried celluloses were determined at -160°C, the single-line spectra recorded had line widths of about 18-24 gauss. On the absorption of water by the irradiated celluloses, the ESR spectra changed and were dependent on the crystalline structure of the irradiated celluloses. The effects of different arrangements of the irradiated celluloses, as shown by their trapped radical spectra, particularly after interaction with water, were discussed.Additional Material: 7 Ill.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesReine, Alden H. ; Hinojosa, Oscar ; Arthur, Jett C.
New York, NY [u.a.] : Wiley-Blackwell
Published 1973Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: Electron spin resonance (ESR) spectra of free-radical intermediates formed during photo-initiated graft polymerization reactions of acrylamide, methacrylamide, and diacetone acrylamide onto purified cotton cellulose were recorded. Purified cellulose was saturated with aqueous solutions of the vinyl monomers (0.5M) and then photolyzed under nitrogen by near-ultraviolet light (3100-4100 Å, peak near 3500 Å) at -196° and 40°C. Other samples of cellulose were saturated with aqueous solutions of the monomers, dried, and then photolyzed at 40°C. In the absence of cellulose, either poorly resolved or no free-radical spectra were generated on photolysis of the monomers. Photolysis of dried cellulose at 40°C and wet cellulose at -196°C initiated formation of a cellulosic radical that generated a singlet spectrum. Photolysis of wet cellulose at 40°C generated no ESR detectable radical; however, photolysis of wet cellulose that contained monomer at 40°C generated poorly resolved spectra. The ESR spectra of the propagating copolymer radicals recorded were poly(acrylamide), three lines; poly(methacrylamide), five lines; and poly(diacetone acrylamide), two lines (doublet).Additional Material: 3 Ill.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesHarris, James A. ; Arthur, Jett C. ; Carra, Jarrell H.
New York, NY [u.a.] : Wiley-Blackwell
Published 1978Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: Unsensitized, photoinitiated polymerization reactions of glycidyl methacrylate from solutions of water and water-methanol with cotton cellulose fabrics were investigated. When several layers of cotton fabrics were immersed in solutions of glycidyl methacrylate and only the surface layer was exposed to light, polymerization reactions were initiated in this layer and also initiated in inner layers of fabrics, probably by chain transfer reactions. Photoinitiated (350 nm, 24 W, 34 min) polymerizations of glycidyl methacrylate (7.5 vol-%) from water (43 vol-%)-methanol (57 vol-%) with cotton fabrics in one-, three-, and six-layered configurations were: one-layered, 32% polymer; three-layered, 30%, 27%, and 25% polymer; and six-layered, 29%, 25%, 22%, 20%, 14%, and 11% polymer. Electron-microscopic examination of the distribution of poly(glycidyl methacrylate) within the cotton fibrous structure showed that polymer was distributed throughout the cross section of the fiber. At the surface of the fibers, the polymer tended to be more concentrated than within the cross section of the fibers and to encapsulate them. Photoinitiated polymerization reactivities of several vinyl monomers from solution with cotton cellulose fabrics were compared with those of glycidyl methacrylate as follows: methyl methacrylate 〉 glycidyl methacrylate 〉 diacetone acrylamide 〉 1,3-butylene dimethacrylate 〉 methacrylic acid 〉 acrylonitrile 〉 divinylbenzene.Additional Material: 6 Ill.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesHarris, James A. ; Arthur, Jett C. ; Goynes, Wilton R.
New York, NY [u.a.] : Wiley-Blackwell
Published 1979Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: Radiation-initiated polymerization of vinyl phosphonate oligomer (molecular weight 500-1000) and N-methylolacrylamide from aqueous solutions was investigated with cotton printcloth, flanelette, and sateen fabrics and with cotton (50%)-polyester (50%) flannelette fabrics. Determinations were made of the effects of radiation dosage, mole ratio of vinyl phosphonate in the oligomer to N-methylolacrylamide in aqueous solution, concentration of reactants, wet pickup of solutions on fabrics, and irradiation of both dry and wet fabrics on efficiency of conversion of oligomer and monomer in solution to polymer add-on. The effects of vinyl phosphonate oligomer and N-methylolacrylamide radiation-initiated polymerization on some of the textile properties of cotton printcloth and on flame resistances of cotton and cotton-polyester fabrics were evaluated. The breaking strength of modified cotton printcloth was about the same as that of unmodified fabric; however, the tearing strength and flex abrasion resistance of modified fabric were reduced. The textile hand of the modified printcloth fabrics that had flame resistance indicated: interaction between cellulose and vinyl phosphonate oligomer-poly(N-methylolacrylamide) and uniform deposition in the fibrous cross section (transmission electron microscopy); surface areas of heavy deposits of oligomer-polymer (scanning electron microscopy); and phosphorus located throughout the fibrous cross section (energy dispersive x-ray analysis). Polymerization of vinyl phosphonate oligomer and N-methylolacrylamide was radiation initiated with cotton-polyester fabric; however, this modified fabric did not have flame-resistant properties.Additional Material: 4 Ill.Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesHarris, James A. ; Arthur, Jett C. ; Goynes, Wilton R.
New York, NY [u.a.] : Wiley-Blackwell
Published 1979Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: Photoinitiated, free-radical reaction of cotton fabric with vinyl phosphonate oligomer (molecular weight 500-1000) and N-methylolacrylamide monomer from aqueous solutions to form copolymer gave a textile product that had flame resistance (FF 5-74 test). The initiating free radicals were formed on the cellulose molecule when cotton fabric was exposed to ultraviolet radiation. The effects of wavelengths of ultraviolet radiation (254, 300, and 350 nm), reaction time (0-9 ksec), solids in solution (10%-60%), atmosphere (air, nitrogen, and oxygen), and oligomer-to-monomer concentration (1:0.00 to 1:1.20 mole ratio) on efficiency of monomer and oligomer conversion to copolymer (maximum efficiency 70%-80%) were determined. Evaluation of the flame resistant cotton fabric by transmission electron microscopy showed deposits of copolymer throughout the cross sections of the fibers. However, scanning electron microscopy and energy-dispersive x-ray analysis showed that copolymer and phosphorus tended to be more concentrated between and on the surfaces of the fibers.Additional Material: 3 Ill.Type of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesStaff View
ISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsAdditional Material: 3 Ill.Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesStaff View
ISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: The intramolecular transfer of high energy in purified cotton cellulose has been demonstrated to occur over distances several times greater than the length of the b axis of a cellobiose unit. The electron spin resonance spectra of fibrous benzoylated cotton cellulose have shown that the concentrations of free radicals initiated in the cellulosic molecule by γ-radiation from Co60 are decreased by the presence of substituted benzoyl groups spaced at least as far apart as 70-80 A. The retention of the breaking strength of fibrous cotton cellulose on exposure to γ-radiation is increased by substitution of benzoyl groups on the cellulose molecule. The substitution of benzoyl groups, spaced at least as far apart as 10-20 A., results in about 80% retention of the initial strength of the fibrous cellulose at dosages as high as 1.3 × 1021 e.v./g. cellulose, as compared with about 20% retention of the initial strength of unsubstituted cellulose at the same dosage. Based on the breaking strengths of the irradiated fibrous celluloses, at a dosage of 1.3 × 1021 e.v./g. cellulose, the average calculated distances between molecular cleavages are increased from about 500 A. for unsubstituted cellulose to about 3000 A. for benzoylated cellulose (degree of substitution 2.0). These energy transfer effects in cellulose of high molecular weight indicate that polymeric carbohydrates can be radioprotected.Additional Material: 4 Ill.Type of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesBaugh, Peter J. ; Hinojosa, Oscar ; Arthur, Jett C.
New York, NY [u.a.] : Wiley-Blackwell
Published 1967Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: An ESR study of the free-radical mechanisms of the post-irradiation reactions of cotton cellulose with acrylonitrile is reported. The effects of atmosphere, moisture content, and solutions of acrylonitrile on the yield and stability of free-radical sites in irradiated cellulose were determined. On interaction of γ-radiation from a 60Co source with cotton cellulose, long-lived free-radical sites were found within the molecular lattice. Short-lived free-radical sites were apparently also formed on chain cleavage, gave strong singlet spectra, and were readily accessible to interaction with water. Other free-radical sites were formed within regions of the cellulosic fiber which were inaccessible to moisture or aqueous solutions even after contact times as long as three days. It was suggested that long-lived free-radical sites in cellulose I (containing regain moisture) resulted from dehydrogenation at C5, and in cellulose II (containing regain moisture) resulted from dehydrogenation at C5 and dehydrogenation of the OH group or dehydroxylation at C6. When irradiated cellulose was contacted with a solution of acrylonitrile (15%) in 75% aqueous zinc chloride, the initial rate of decrease in spin concentration was higher than the rate of decrease as the time of contact increased. The ESR spectrum of the reacted cellulose, observed at -100°C., as compared with the spectrum for the irradiated cellulose, had decreased in signal strength with increase in time of contact and changed from a three-line spectrum to an ill-defined spectrum. The free radical being observed was probably due to unreacted sites in the cellulose. The extent of the graft copolymerization reaction was directly related to the initial spin concentration in the irradiated cellulose.Additional Material: 8 Ill.Type of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesMorris, Nelle J. ; Blouin, Florine A. ; Arthur, Jett C.
New York, NY [u.a.] : Wiley-Blackwell
Published 1968Staff ViewISSN: 0021-8995Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: A method of separation of polyvinyl side chains from grafted polyacrylonitrile-cotton copolymers was developed in order to study the effect of length of side chain on copolymer properties. The method consists of dispersion of the copolymer (1 g.) containing 20% polyacrylonitrile in 75% aq. ZnCl2 (100 ml.), addition of 6N HCl (100 ml.), heating for 1 hr. at 100°C., and precipitation and purification of the resulting vinyl polymer. The effect of hydrolysis on the intrinsic viscosity, the nitrogen content, and the infrared absorption spectra of the polyacrylonitrile polymers was investigated. It was concluded that this method of separation of the grafted polymers permitted a comparison of samples grafted by various techniques. A series of grafted copolymers was hydrolyzed, and the molecular weights of the isolated products were determined by measurements of intrinsic viscosity. Copolymer samples prepared by a post-irradiation grafting technique had the longest polyacrylonitrile side chains (molecular weight, 1 × 106). Samples grafted by a simultaneous irradiation technique varied in side-chain length, depending upon the monomer-solvent system used in the preparation of the copolymer (molecular weight, 3 × 104-5 × 105). Chemically initiated grafting to cotton resulted in a copolymer containing relatively short side chains (molecular weight, 9 × 104).Additional Material: 2 Tab.Type of Medium: Electronic ResourceURL: