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  • 1
    Electronic Resource
    Electronic Resource
    Synthesis and properties of copolymers from 2-hydroxyethyl methacrylate-linked nonsteroidal antiinflammatory agents with methacrylic acid (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1481-1490 
    Details
    ISSN: 0887-624X
    Keywords: ibuprofen ; ketoprofen ; naproxen ; copolymer reactivity ; thermal stability ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Three nonsteroidal antiinflammatory drugs, 2-(4-isobutylphenyl)-propionic acid (ibuprofen), 2-(3-benzoylphenyl)-propionic acid (ketoprofen), and 2-(6-methoxy-2-naphthyl)-propionic acid (naproxen), were covalently linked with 2-hydroxyethyl methacrylate (HEMA). The drug-linked HEMA (M1) (ibuprofen-linked HEMA abbreviated as HI; ketoprofen-linked HEMA as HK, and naproxen-linked HEMA as HN), were respectively copolymerized with methacrylic acid (M2), MA, to obtain macromolecular prodrugs. The compositions of the copolymers were determined by means of a 1H-NMR spectroscopy and monomer reactivity ratios were estimated using the Kelen-Tüdös linear differential equation. The reactivity ratios are: r1 = 0.101 ± 0.012, r2 = 1.071 ± 0.065 for HI-MA; r1 = 0.344 ± 0.066, r2 = 0.966 ± 0.032 for HN-MA, and r1 = 0.650 ± 0.182, r2 = 1.032 ± 0.106 for HK-MA, respectively. The monomer reactivity toward to MA radical estimated from 1/r2 values is almost same for all three monomers (1/r2 ∼ 1). The glass transition temperatures of three drug-linked homopolymers go hand in hand with the steric hindrance of three drugs, i.e., ketoprofen 〉 naproxen ≫ ibuprofen calculated the minimum energy by computer molecular modeling. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1481-1490, 1998
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    A study on the plasma polymerization of some cyano-containing compounds and their electrical properties (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 3799-3809 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Plasma polymerization of some cyano-containing organic compounds was carried out at 13.56 MHz from the gas phase. The resulting polymer films were smooth and pinhole free. The electrical conductivities of the polymer films varied from 10-12 to 10-7 S cm-1 depending upon which cyano-containing monomer was used. The Al/polymer film/ITO (indium-tin oxide) sandwich cells made from the films demonstrated a photovoltaic effect, and some of them showed good rectifying behavior. Infrared spectroscopy (IR) and ultraviolet spectroscopy (UV) were utilized to characterize the structure of the product polymers. The effects of the original structure in the starting monomers on the structure of the resulting polymers are investigated. The influence of incident light intensity on the photovoltaic characteristics was also investigated.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080271120
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  • 3
    Electronic Resource
    Electronic Resource
    Depolymerization of poly(ethylene terephthalate) resin under pressure (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 42 (1991), S. 1501-1507 
    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 process of depolymerization of PET resin by EG glycolysis under pressure is investigated. The kinetics of this pressurized depolymerization of PET resin is discussed. It was found that the rate of depolymerization is dependent of temperature, pressure, and concentration ratio of EG to PET. The rate of depolymerization is proportional to the square of EG concentration and faster than that under atmospheric pressure. Glycolyzed products under pressure consist of the PET monomer, BHET, and oligomers, mostly dimer and trimer. An equilibrium between BHET and oligomers is attained quickly soon after the depolymerization step is completed in the case of a higher ratio of EG/PET used. In the case of lower ratio of EG/PET, the final product now consists of higher molecular weight of oligomers rather than monomer, dimer, and trimer.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070420603
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  • 4
    Electronic Resource
    Electronic Resource
    Low loss second-order nonlinear optical polymers based on all organic sol-gel materials (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 55 (1995), S. 209-214 
    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 new class of all organic sol-gel second-order nonlinear optical (NLO) materials based on hexa(methoxymethyl) melamine (HMM) was developed. Two NLO active chromophores, 4 (4′-nitrophenylazo) aniline (DO3) and 4-amino-4′-nitrobiphenyl (ANB), were incorporated into the melamine matrices. The samples exhibited second-order optical nonlinearity after poling and curing at 220°C for 30 min. DO3/HMM and ANB/HMM samples showed a second harmonic coefficient, d33 of 10.7 and 1.8 pm/V at 1064 nm, respectively. The temporal stability of both systems was studied at room temperature as well as at 100°C. Waveguide optical losses of samples at 633 and 830 nm were found. © 1995 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1995.070550203
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  • 5
    Electronic Resource
    Electronic Resource
    The determination of polymer interfacial tension by drop image processing: Comparison of theory and experiment for the pair, poly(dimethyl siloxane)/polybutndieneThis paper is dedicated to Prof. Bryce Maxwell on the occasion of his retirement from Princeton University (1986)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 26 (1986), S. 1410-1418 
    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: The interfacial tensions of immiscible binary blends of poly(dimethyl siloxane) (PDMS) and polybutadiene (PBD) have been determined as a function of molecular weight and temperature. The technique employed for these measurements takes advantage of recent advances in the determination and analysis of pendant fluid drop profiles. The experimental data are compared to the predictions of square gradient theories and theories based on the diffusion equation approach as developed by Helfand and co-workers. Qualitative agreement is obtained with both types of theory when the Flory-Huggins interaction parameter is taken to be comprised of two terms: a temperature independent term of entropic origin; and an enthalpic term that is inversely dependent upon the temperature.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760262010
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  • 6
    Electronic Resource
    Electronic Resource
    Phase separation of poly(ether sulfone imide) modified epoxy resin (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 61 (1996), S. 2423-2435 
    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: Poly(ether sulfone imide)s (PEI) with molecular weight Mn ∼ 104 were synthesized from 3,3′,4,4′-benzophenone tetracarboxylic dianhydride and amine terminated poly(ether sulfone) having molecular weights ranging from Mn ∼ 400 to Mn ∼ 4000. Thus, the PEIs had the same molecular weight but various imide and ether sulfone contents. The PEIs were mixed with a stoichiometric mixture of diglycidyl ether bis-phenol-A (DGEBA)/diamino diphenyl sulfone (DDS). The effect of PEI on the curing reaction of DGEBA/DDS and the morphology of the polymer blend were studied by differential scanning calorimetry (DSC) and optical microscopy. In the DGEBA/DDS/PEI blend with a fixed PEI molecular weight and PEI concentration but with various imide content, the experimental data revealed the PEI with a higher content of ether sulfone had a lower Tg and a better compatibility with solvents and epoxy resins; the curing reaction rate of DGEBA/DDS/PEI was faster for PEI with a higher imide content; the DSC data of cured DGEBA/DDS/PEI showed two Tgs, indicating phase separation between PEI and cured epoxy resins; and the data of optical microscopy showed that the compatibility of PEI with epoxy resins increased with the content of ether sulfone in PEI. © 1996 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Ultrasonic devulcanization of rubber vulcanizates. I. Process model (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 59 (1996), S. 803-813 
    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: Tire and rubber waste recycling is an important issue facing the rubber industry. In addressing this issue, the present article describes the first attempt to formulate a model and to simulate a novel continuous ultrasonic devulcanization process. The proposed model is based upon a mechanism of rubber network breakup caused by cavitation, which is created by high-intensity ultrasonic waves in the presence of pressure and heat. Dynamics of bubble behavior is described by the Notlingk-Neppiras equation with incorporation of an additional term based upon elastic strain-energy potential. Acoustic pressure arising in the ultrasonic field is related to void formation. Their concentration is calculated based upon nucleation and growth of gas bubbles in crosslinked elastomers under negative driving pressure. The breakup of a three-dimensional network in crosslinked rubbers is combined with flow modeling. The viscosity function required for this modeling is based upon a power-law model which includes temperature, shear rate, and gel fraction dependence. © 1996 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Ultrasonic devulcanization of rubber vulcanizates. II. Simulation and experiment (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 59 (1996), S. 815-824 
    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 simulation results based on the devulcanization model presented in Part I of this study are described for devulcanization of SBR vulcanizates. The vulcanizates are conveyed by a single-screw extruder to a thin gap between a stationary die and a vibrating horn. Gapwise velocity, temperature, and shear-rate distributions along the die length are calculated. Predictions of the model for changes of various structural characteristics including gel fraction, fraction of various broken bonds, rate of their breakup, and void formation along die length are given. Devulcanization energy consumption and energy dissipated by ultrasonic waves are calculated. Comparison of these energies indicates that the devulcanization energy represents only a small fraction of the dissipated energy. The predicted results for gel fraction, crosslink density, die characteristics, and “mixing cup” temperature are compared with the experimental data. These predicted results are found to be only in qualitative agreement with experimental observations. The theoretical and experimental results indicate that the rubber is partially devulcanized and the devulcanization process is accompanied by some degradation of the macromolecular chains. © 1996 John Wiley & Sons, Inc.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Preparation of gradient-index (GRIN) polymer fibers for imaging applications (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 60 (1996), S. 1379-1383 
    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 closed extrusion process combined with a core-shell separation die design is developed in this study for preparing gradient index (GRIN) polymer fibers with a quadratic distribution of the refractive index. The material system used in this investigation is methyl methacrylate (MMA, n = 1.49) and benzyl methacrylate (BzMA, n = 1.568). The refractive index differences between the center and the periphery (Δn) of the prepared polymer fibers increase from 0.0115 to 0.020 when BzMA in the reactant mixtures increases from 17 to 28%. This finding would suggest that increasing the high refractive index monomer in the reactant mixture increased Δn. The Δn values decrease from 0.018 to 0.0135 when the diffusion zone temperature increases from 70 to 90°C. The diffusion rates of the monomers increase with the temperature, thereby causing BzMA and MMA to distribute more uniformly at a higher temperature than at a lower one. This uniform distribution leads to the decrease of Δn with an increasing temperature. The prepared GRIN polymer fibers have potential applications as imaging lenses for scanners, fax machines, and copiers. © 1996 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Solute-membrane interactions in hyperfiltration (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 33 (1987), S. 1809-1822 
    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 performances of several composite membranes (PEC-1000, Teijin, HR-95, HR-98) and one asymmetric membrane (Solrox SC-200) in hyperfiltration are compared at 25°C using different aqueous feed solutions (0.1M and 0.5M NaCl, 0.5M 1,3-and 1,4-dioxan, 0.1M benzyl alcohol and 2-methoxybenzyl alcohol, 1,2- and 1,4-butandiol, and Triton feed solution). The effects of solute dissociation, polarization, and hydrogen bonding ability on solute permeability are discussed; steric effects are also being considered. Strong solute-membrane interactions are exhibited in hyperfiltration by systems with distinct hydrogen bonding capabilities of the solute with functional sites of the membrane matrix. Knowledge of solute-membrane interactions can be useful for elaborating separation and transport mechanisms.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070330532
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