ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 266 (1988), S. 587-593 
    ISSN: 1435-1536
    Keywords: Controlled release of drug ; capsule ; poly(α amino acid)s ; membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The release behavior of a water-soluble drug through membranes made of poly(L-leucine) and its copolymer with different hydrophilic properties was studied. The effect of casting methods on the release rate was also investigated. It was found that the membrane with a higher hydrophilic property resulted in a higher permeation rate. The capsule was prepared as a composite sheet from a poly(L-leucine)-prednisolone 21-sodium succinate sponge and a poly(L-leucine) membrane. Release of the water-soluble drug from the capsule was found to be effectively governed by the hydrophilic character and thickness of the outer membrane. Biocompatibility studies carried out by implanting the poly(L-leucine) sponge subcutaneously in the dorsal surface of the rat showed that the sponge had a good biocompatibility and slow biodegradation. It was concluded from these results that poly(L-leucine) should be a suitable material for preparing a controlledrelease drug device for long-term dosage.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 34 (1987), S. 2151-2162 
    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 dynamic mechanical properties, transition behavior, and morphology of polycarbonate (PC)-polyurethane (PU) semi-interpenetrating polymer networks (semi-IPNs) and linear blends were studied by means of Rheovibron, differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). Two glass transition temperatures corresponding to polycarbonate and polyurethane were observed and microphase separation was further evident with TEM. In PC/PU semi-IPNs, two glass transition temperatures were shifted inwardly indicating that the interpenetrating network of polyurethane increases the mutual miscibility of PC and PU. The average phase domain was 500Å in semi-IPNs and the phase domains were in the range 1000-6000 Å in linear blends of the corresponding polymers. The compatibilities of PC and PU were greatly influenced by the molecular weight of polyols in PU prepolymer and the ratio of NCO/OH; lower molecular weight polyols and higher NCO/OH ratio resulted in better compatibility, and finer phase domains in PC and PU linear blends and semi-IPNs.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 34 (1987), S. 559-569 
    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 effects of composition, molecular weight, and milling temperature on homogeneity, gas permeability, selectivity of oxygen/nitrogen, and mechanical strength of the TPX/siloxane blend membranes were studied. By adjusting the blending conditions and hence controlling the homogeneity, the gas permeability of TPX membrane was significantly improved without loss of oxygen/nitrogen selectivity. The oxygen permeability of 1.57 × 10-8 cm3 (STP) cm/cm2 s cm Hg and the oxygen/nitrogen permeation ratio of 6.92 can be obtained under the condition of TPX (MX-001)/siloxane (75,000 MW) = 9/1 at 65°C milling temperature. This membrane possesses 133 kg/cm2 tensile strength and 92% elongation. The morphology of the blend membranes was studied.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 37 (1989), S. 2907-2919 
    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: Utilizing the factors of degradation and crosslinking of TPX polymer and high O2/N2 selectivity of MMA, the performances of MMA homografted TPX membrane are efficiently improved compared to those of pure TPX membrane. The degradation and crosslinking of TPX polymer solution with or without dissolved oxygen during irradiation were observed and proved in existence by the gas permeability, mechanical, and viscosity change study. High O2/N2 permeability ratio of 7.6 and fairly high oxygen permeability of 28 × 10-10 cm3 cm/cm2 s cm Hg of the membrane which was cast from the degassing polymer solution, with 20% degree of MMA grafting, can be obtained. Also the membrane for high oxygen permeability of 63 × 10-10 cm3 cm/cm2 s cm Hg with an O2/N2 permeability ratio of 4.5, which was cast from the polymer solution with dissolved oxygen, can be obtained under the condition of 60 h irradiation time and about 7% degree of grafting. O2/N2 selectivity of TPX membrane can be improved by homografting method with lower MMA grafting degree than that of heterografting method.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 42 (1991), S. 2525-2534 
    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: Carbon fiber are surface treated by oxygen, argon, and styrene plasma to study the effects on fiber strength and interfacial shear strength with PPS resin. Interfacial shear strength between carbon fiber and high melting temperature thermoplastic resins is successfully measured with the microbond pull-out test with the help of scanning CO2 laser beam which solved the difficulties in preparing PPS microspheres. Tensile tests show that etching by oxygen plasma and deposition with plasma-PS increase strength of the fibers in some cases. ESCA spectra deconvolutions demonstrate that the improved interfacial strength is strongly related to the hydroxyl, ether, or aromatic groups on the surface. On the other hand, hydrocarbon segments are detrimental to the interface. Surface area and roughness have little influences on the interfacial strength of carbon fiber/PPS composites.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 47 (1993), S. 1513-1522 
    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: Polycarbonate (PC) membranes possess high O2/N2 selectivity and mechanical strength, but have low gas permeability. In order to improve the pure PC membrane's gas permeability and selectivity of O2/N2, in this study we attempt to combine transition metal salts into the membrane to form a complex membrane. Tensile strength and elongation at break of the membrane are not significantly changed. The effect of casting solution composition and solvent evaporation time on morphology, gas permeability, and selectivity of O2/N2 of PC membranes are studied. The gas permeabilities of PC/DMF/Metals membranes are significantly improved, as compared to those of pure PC membrane. For example, an oxygen permeability of 137 cm3 (STP)-cm/cm2-sec-cmHg and separation ratio of oxygen to nitrogen of 4.0 for PC/DMF/CuCl2 membrane with [PC/CH2Cl2]/[CuCl2/DMF] = 17/3 mL/mL, and CuCl2/DMF = 0.1 g/mL, can be obtained. The FT-IR spectra and elementary analysis suggest that there is interaction among metal, DMF, and PC. © 1993 John Wiley & Sons, Inc.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 62 (1996), S. 1347-1360 
    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: Kevlar 49 fibers were surface-modified by NH3-, O2-, and H2O-plasma etching and chlo-rosulfonation and subsequent reaction with some reagents (glycine, deionized water, eth-ylendeiamine, and 1-butanol) to improve the adhesion to epoxy resin. After these treatments, the changes in fiber topography, chemical compositions of the fiber surfaces, and the surface functional groups introduced to the surface of fibers were identified by SEM, XPS, and static SIMS. Interlaminar shear strength (ILSS) and T-peel strenght between the fiber and opoxy resin, as measured by the short-beam test and T-peel test, were remarkedly improved by gas plasma and chlorosulfonation (0.1% and 0.25% CISO3H at 30 s). However, from the results of similar GIC values of the treated and untreated fiber composites, it is clear that the fiber/matrix interfacial bond strength is only a minor contributor to GIC. SEM was also used to study the surface topography of the fracture surfaces of composites in T-peel test. It could be seen from SEM observations that the improvement of fiber/matrix interfacial bond strength often accompanied a change in fracture mode from the interface of fiber/epoxy resins to the fiber fibrillation and the resins. © 1996 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 1988-07-01
    Print ISSN: 0372-820X
    Electronic ISSN: 1435-1536
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 1979-10-01
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2011-08-17
    Description: In a previous publication from this laboratory, the Rouse-Bueche-Zimm molecular theory of viscoelasticity has been extended by using a transient network model to apply to binary blends of monodisperse polymers with chain entanglements. The dynamics of the entanglements were modeled both by the enhanced frictional coefficients and by the additional elastic couplings. It was recognized that entanglements not only may form between chains of the same lengths (intracomponent entanglements) but also between those of different lengths (intercomponent entanglements). At a given intercomponent entanglement, the longer chain was assumed to have the frictional coefficient of the shorter chain. Similarly, for blends consisting of several monodisperse components with different molecular weights, such modifications are also required to predict their linear viscoelastic behavior. The frequency of these interactions is assumed to be proportional to the weight ratio of the respective component chains in the blend. Equations of motion are formulated for each component and solved numerically for the relaxation time spectra. Linear viscoelastic properties such as the dynamic mechanical moduli, stress relaxation moduli, and zero-shear viscosity can then be computed for these systems by linear summation of those of the components.
    Keywords: NONMETALLIC MATERIALS
    Type: Journal of Applied Physics; 50; Oct. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...