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Solid Polymer (solid + polymer)

Distribution by Scientific Domains
Polymers and Materials Science60%

Terms modified by Solid Polymer

  • solid polymer electrolyte
    		•

    Selected Abstracts

    Plastic energy dissipation and its role on heating/melting of single-component polymers and multi-component polymer blends

    ADVANCES IN POLYMER TECHNOLOGY, Issue 2 2003
    Bainian Qian
    Abstract Plastic energy dissipation (PED) of polymer particulates is, essentially, the energy dissipated during large and repeated plastic deformations of compacted polymer particulates while still in the solid state. PED is higher or much higher than VED, the viscous energy dissipation source of polymeric melts, because the stresses necessary to plastically deform viscoelastic polymer solids are orders of magnitude higher than the stresses needed to support viscous flow. In the last few years our group has demonstrated experimentally the dominant role which PED plays in the heating/melting of solid polymer (compacted) particulate beds in compounding processing equipment, such as twin-screw extruders and counterrotating continuous mixers/melters, in which the deformation of solid polymers is mandatory. We have also developed simple empirical methods of predicting the total axial distance needed for melting a given polymer in specific processing/compounding machines and processing. conditions, as well as the melting rates, all based on the mechanical energy dissipated during solid particulate compression. This work explores the more complex issue of how the PED behavior of single-component polymers may affect the PED (and the heating/melting) behavior of multi-component polymer blends. © 2003 Wiley Periodicals, Inc. Adv Polym Techn 22: 85,95, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.10039 [source]

    Synthesis and Unusual Swelling Behavior of Combined Cationic/Non-Ionic Hydrogels Based on Chitosan

    MACROMOLECULAR BIOSCIENCE, Issue 10 2003
    Mehrdad Yazdani-Pedram
    Abstract Hydrogel-forming copolymers based on chitosan grafted with different amounts of polyacrylamide were synthesized and its swelling capacity determined in distilled water, sodium chloride solutions, as well as in buffer solutions at pH 1.2 and 8.0. The resulting products are highly efficient as hydrogel-forming materials with swelling at equilibrium going approximately from 300 to 3,000 times the volume of the dry solid polymer in all the investigated media. The products, different to usual hydrogels, swells considerably more and quickly in electrolyte-containing solutions compared to in distilled water. This has been attributed to their structure that contains non-ionic polyacrylamide macromolecules grafted onto the trunk polymer chitosan, which is cationic in nature. In-vitro drug-release behavior of formulations containing grafted copolymers have been tested using theophylline as a water-soluble drug and the results were compared with similar formulations containing unmodified chitosan. It was found that tablets based on formulations containing grafted chitosan show higher erosion and swelling compared with those of the matrix based on unmodified chitosan, leading to a higher fraction of theophylline released. It can be concluded that formulations based on the synthesized copolymers are potentially useful for fluid absorbency and as prolonged drug-release matrices. The swelling of one of the hydrogels studied here. [source]

    Light-induced crosslinking polymerization,

    POLYMER INTERNATIONAL, Issue 11 2002
    Christian Decker
    Abstract Light-induced polymerization of multifunctional monomers is a powerful method to transform a liquid resin into a solid polymer almost instantly, selectively in the illuminated areas. The reaction can conveniently be followed by real-time infrared spectroscopy, a technique which records directly conversion versus time curves in photosensitive resins undergoing ultrafast curing upon UV or laser exposure. The photoinitiator was shown to play a key role in laser-induced polymerization because of the monochromatic character of the emitted radiation. By using highly sensitive acrylate photoresists, relief images of micronic size were obtained by fast scanning with a focused laser beam. The laser direct imaging technology makes image transfer obsolete and eliminates the manufacture of photolithographic masks. Polymer networks of different architectures have been obtained by UV irradiation of various monomer blends: acrylate,epoxide, acrylate,vinyl ether, acrylate,polyene, vinyl ether,maleate and thiol,polyene. With monomers polymerizing by different mechanisms, ie radical and cationic types, interpenetrating polymer networks have been generated upon UV exposure in the presence of adequate photoinitiators. The crosslinking reaction was also performed in the solid state on polybutadiene which was plasticized with a multifunctional acrylate or thiol monomer. Thermoplastic elastomers were transformed within a fraction of a second into an insoluble material showing a greatly improved resistance to heat and chemicals, because of the tight polymer network formed. © 2002 Society of Chemical Industry [source]

    Plastic energy dissipation and its role on heating/melting of single-component polymers and multi-component polymer blends

    ADVANCES IN POLYMER TECHNOLOGY, Issue 2 2003
    Bainian Qian
    Abstract Plastic energy dissipation (PED) of polymer particulates is, essentially, the energy dissipated during large and repeated plastic deformations of compacted polymer particulates while still in the solid state. PED is higher or much higher than VED, the viscous energy dissipation source of polymeric melts, because the stresses necessary to plastically deform viscoelastic polymer solids are orders of magnitude higher than the stresses needed to support viscous flow. In the last few years our group has demonstrated experimentally the dominant role which PED plays in the heating/melting of solid polymer (compacted) particulate beds in compounding processing equipment, such as twin-screw extruders and counterrotating continuous mixers/melters, in which the deformation of solid polymers is mandatory. We have also developed simple empirical methods of predicting the total axial distance needed for melting a given polymer in specific processing/compounding machines and processing. conditions, as well as the melting rates, all based on the mechanical energy dissipated during solid particulate compression. This work explores the more complex issue of how the PED behavior of single-component polymers may affect the PED (and the heating/melting) behavior of multi-component polymer blends. © 2003 Wiley Periodicals, Inc. Adv Polym Techn 22: 85,95, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.10039 [source]

    Kinetic Study and New Applications of UV Radiation Curing

    MACROMOLECULAR RAPID COMMUNICATIONS, Issue 18 2002
    Christian Decker
    Abstract Highly crosslinked polymers can be readily synthesized by photoinitiated polymerization of multifunctional monomers or functionalized polymers. The reaction can be followed in situ by real-time infrared (RT-IR) spectroscopy, a technique that records conversion versus time curves in photosensitive resins undergoing ultrafast polymerization upon UV exposure. For acrylate-based resins, UV-curing proceeds with long kinetic chains (7700 mol/radical) in spite of the high initiation rate. RT-IR spectroscopy proved very valuable in assessing the influence of various parameters, such as initiation efficiency, chemical structure of the telechelic oligomer, light intensity, inhibitory effect of oxygen, on polymerization kinetics. Interpenetrating polymer networks can be rapidly synthesized by means of UV irradiation of a mixture of difunctional acrylate and epoxy monomers in the presence of both radical and cationic-type photoinitiators. The same UV technology can be applied to crosslink solid polymers at ambient temperature, which bear different types of reactive groups (acrylate and vinyl double bonds, epoxy ring). UV radiation curing has been successfully used to produce within seconds weathering resistant protective coatings, high-resolution relief images, glass laminates and nanocomposites materials. Photoinitiated crosslinking polymerization. [source]