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  • 1
    Electronic Resource
    Electronic Resource
    The microwave radiation effect on the polymerization of styrene (1996)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 34 (1996), S. 2087-2094 
    Details
    ISSN: 0887-624X
    Keywords: microwave ; radiation ; PMMA ; PS ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Styrene was cured by microwave radiation at two different powers: 300 and 500 W. The temperature profile of the sample during the microwave curing process was determined to select a suitable temperature for comparison with the conventional method of cure. The results indicate a similar comparable temperature of about 80°C irrespective of the microwave power used. The percentage conversion of the cure was followed by Fourier transform infrared (FTIR) spectroscopy. The thermal polymerization at 79(±1)°C displayed a gradual increase in the rate of reaction at the gel effect from about 30 to 50% conversion of the reaction. The microwave cure at 300 and 500 W displayed a large and sharp gel effect from about 20 to 69 and 64% conversion of the reaction, respectively. The limiting conversion decreased with increase in microwave power which was also observed in the polymerization of methyl methacrylate (MMA). Based on similarity in temperature and reaction conditions, the 500 W cure was found to show a reaction rate enhancement of 190% and the 300 W cure 120%. A comparison of microwave induced reactions with thermal methods, therefore, must also specify the microwave power used. © 1996 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Synthesis and characterization of anhydride-functional polycaprolactone (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 1139-1148 
    Details
    ISSN: 0887-624X
    Keywords: polycaprolactone ; chemical grafting ; anhydride-functional polymer ; FTIR ; 1H-NMR ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polycaprolactone-graft-maleic anhydride (PCL-g-MA) copolymer was prepared by grafting maleic anhydride onto PCL in a batch mixer and in an extruder using dicumyl peroxide as the initiator. The graft content was determined with the volumetric method by converting the anhydride functions to acid groups and then titrating with ethanolic potassium hydroxide. The grafted polymer was extracted with xylene to remove any unreacted monomer before the estimation step. The effect of temperature and the various concentrations of the initiator and monomer used for the grafting reaction were investigated. The presence of residual initiator in the reaction product was checked using thin-layer chromatography. Molecular weight determination was carried out for the pure and grafted polymer using gel permeation chromatography to determine if chain scission was present. Results indicate that maleic anhydride is grafted onto PCL using free radical initiators. The grafting reaction was confirmed by FTIR and NMR techniques. FTIR spectra showed absorption bands around 1785 and 1858 cm-1. NMR spectra gave signals for methine proton at 3.47 ppm. For a given peroxide level, a higher temperature or residence (reaction) time gave higher percentage of grafted MA. There was an optimum temperature and initiator concentration after which the percentage of MA grafted on PCL decreased. The number-average molecular weight, tensile strength, and the percent elongation of PCL-g-MA were comparable to those of PCL before grafting. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1139-1148, 1997
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Synthesis, characterisation and catalytic activity of styrene-divinylbenzene copolymer (XAD-2) bound palladium (II) complex (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Polymer International 34 (1994), S. 369-373 
    Details
    ISSN: 0959-8103
    Keywords: chloromethylation ; styrene-divinylbenzene copolymer ; 1,2-diaminopropane ; cyclohexane ; kinetics of hydrogenation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Polymer-anchored Pd(II) complex catalyst was sythesised by sequential attachment of 1,2-diaminopropane as a ligand to the chloromethylated commercially available styrene-divinylbenzene copolymer (XAD-2). The catalyst was characterised using techniques such as FTIR, SEM, EPR, and UV-VIS reflectance spectroscopy. Other physicochemical properties, such as bulk density, moisture content, swelling and surface area by the BET method at low temperature by nitrogen adsorption, were also studied. The catalyst was tested for the rate of hydrogenation of cyclohexene. The influence of various factors such as temperature, concentration of catalyst, substrate, and quantity of solvent have been determined. The results are compared with the homogeneous analogue. The recycling efficiency of the catalyst was also studied.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pi.1994.210340403
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  • 4
    Electronic Resource
    Electronic Resource
    The role of steric effects in the adsorption of chemically similar probes to a poly(methyl methacrylate) surface (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 51 (1994), S. 695-699 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The role of steric effects in the adsorption of chemically similar acidic probes to the model basic surface of poly(methyl methacrylate) (PMMA) was examined using the technique of inverse gas chromatography (IGC). The results were expressed in terms of the acid-base contribution to the Gibbs free-energy change upon adsorption. The acid-base component of the adsorption free energy, computed on the basis of theoretical modes of adduct formation, was found to depend strongly on the molecular structure of the adsorbate, suggesting the importance of steric effects. © 1994 John Wiley & Sons, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1994.070510415
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  • 5
    Electronic Resource
    Electronic Resource
    Conversion of agricultural residues into cation exchange materials (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 61 (1996), S. 2099-2105 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A series of cation exchange resins were prepared from some low-value agricultural residues. Carboxylate (maleate, succinate, and phthalate), phosphate, and sulfate groups were incorporated onto the complex polysaccharide matrix of oat hulls, corn cobs, and sugar beet pulp. Standard reaction conditions were established, using cellulose as the model polysaccharide. The magnitude of functional group incorporation, under standard conditions, was taken as a measure of the reactivity of the agricultural residues studied. In general, the order of reactivity was sugar beet pulp 〉 corn cob 〉 oat hull. The unsubstituted and the functionalized agricultural residues were tested for their potential ability to remove cations from waste water discharges. The capability of these materials to remove cations from waste waters was estimated from their calcium binding capacity. The calcium binding capacities of the resins prepared from the agricultural residues varied from around 559-3466 μequiv/g. © 1996 John Wiley & Sons, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Nonlinear response and thermomechanochemical degradation of a urethane elastomer (1987)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 27 (1987), S. 131-140 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: We have studied the failure of a urethane elastomer due to cyclic compressive loading, using loading frequencies and specimen sizes for which internal heat generation is an important factor. The eventual failures were generally manifest by internal cracks growing transverse to the loading direction. A variety of experimental analyses indicate that this failure is primarily thermal, in that the temperature rise due to viscous dissipation eventually leads to a melting of the hard segment domains which act to reinforce the material. No strong indication of thermal or thermomechanical bond scission was obtained, although a progressive reduction in the rubbery modulus was noted.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760270206
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  • 7
    Electronic Resource
    Electronic Resource
    Adaptation of an automatic densimeter as detector for gel permeation chromatography (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 1159-1162 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1978.070220425
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  • 8
    Electronic Resource
    Electronic Resource
    Thermal analysis of styrene-alkyl methacrylate polymers. I. Glass transition temperatures (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 2275-2283 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The glass transition temperatures (Tg's) of several polystyrenes and styrene-alkyl methacrylate copolymers and terpolymers were measured using thermomechanical analysis (TMA) and differential scanning calorimetry (DSC). The polymers studied had number-average molecular weights from 3000 to 250,000 g/mole. The results indicate that the composition dependence of the Tg's for the copolymers and terpolymers can be satisfactorily described by a general Fox equation. In general, the measured Tg's of the copolymer and terpolymer samples depend more on the steric effects of the constituent pendent groups than on their molecular weights. The chain flexibility rather than the size of the pendent group is the determining factor in the glass transition properties of the styrene polymers.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1978.070220819
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  • 9
    Electronic Resource
    Electronic Resource
    Thermal analysis of styrene-alkyl methacrylate polymers. II. Thermogravimetric kinetics (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 2285-2293 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The thermal stability and degradation kinetics of several polystyrenes and styrene-alkyl methacrylate copolymers and terpolymers with a number-average molecular weight (M̄n) of 6000-250,000 g/mole have been studied using dynamic thermogravimetry (TG). The degradation kinetics of each polymer sample have been successfully attributed to a sample first-order reaction expression. The results indicate that the thermal stability and degradation kinetics of the polymers are independent of the size of the molecules within the molecular weight range investigated. The steric hindrance effects of the pendent groups appear to be responsible for the improved thermal stability and resistance of C—C bond scission in the styrene-alkyl methacrylate copolymers and terpolymers.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1978.070220820
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  • 10
    Electronic Resource
    Electronic Resource
    The synthesis and properties of a cation-exchange resin prepared by the pyrolysis of starch in the presence of phytic acidNames are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable. (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 57 (1995), S. 385-390 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A black charcoal-like material having cation exchange and adsorption properties was prepared by the controlled pyrolysis of starch in the presence of a commercial phytic acid solution. Resins with binding capacities of 0.7-5.7 meq/g of calcium were prepared by varying the phytic acid to starch ratio, the temperature, or the duration of heating of the reaction mixture. SEM photomicrographs of some of these new materials showed that they are composed of particles similar in size and shape to the starting starch granules. These resins also removed atrazine from aqueous solutions. © 1995 John Wiley & Sons, Inc.This article is a US Government work and , as such, is in the public domain in the United States of America.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1995.070570315
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