[PDF] The Morphological Behavior Of Model Graft Copolymers eBook

Author : Gunther Molau
Publisher : Springer Science & Business Media
Page : 326 pages
File Size : 43,55 MB
Release : 2012-12-06
Category : Technology & Engineering
ISBN : 1468419080

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The molecules of block and graft copolymers are molecules of a higher order; they consist of homopolymer subchains which are interconnected by chemical valence bonds. This structural com plexity is manifested in the unusual behavior of block and graft copolymers both in solution and in bulk. Many types of interac tions are possible in block and graft copolymers in the solid state. Polymer subchains of one molecule can interact with other polymer subchains which may belong to the same molecule or to different molecules. Since polymer chains of chemically different composition are usually incompatible, thermodynamically unfavorable as well as thermodynamically favorable interactions exist in the solid state. In solutions of block and graft copolymers, the sit uation becomes even more complex, because interactions between the solvent molecules and the various subchains of the copolymer mole cules occur in addition to the interactions between the polymer chains. This multitude of interactions gives rise to a wide spec trum of colloidal and morphological properties which have no paral lel in less complex polymer systems such as homopolymers or random copolymers. Research on the colloidal and morphological behavior of block and graft copolymers is a relatively new field of endeavor. It started in 1954, when F. M. Merrett fractionated mixtures of grafted na tural rubber with the corresponding homopolymers and observed that colloidal sols were formed at certain points during his fractional precipitations.

Author : Gunther Molau
Publisher : Springer
Page : 328 pages
File Size : 10,74 MB
Release : 1971-04-01
Category : Technology & Engineering
ISBN : 9780306305276

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The molecules of block and graft copolymers are molecules of a higher order; they consist of homopolymer subchains which are interconnected by chemical valence bonds. This structural com plexity is manifested in the unusual behavior of block and graft copolymers both in solution and in bulk. Many types of interac tions are possible in block and graft copolymers in the solid state. Polymer subchains of one molecule can interact with other polymer subchains which may belong to the same molecule or to different molecules. Since polymer chains of chemically different composition are usually incompatible, thermodynamically unfavorable as well as thermodynamically favorable interactions exist in the solid state. In solutions of block and graft copolymers, the sit uation becomes even more complex, because interactions between the solvent molecules and the various subchains of the copolymer mole cules occur in addition to the interactions between the polymer chains. This multitude of interactions gives rise to a wide spec trum of colloidal and morphological properties which have no paral lel in less complex polymer systems such as homopolymers or random copolymers. Research on the colloidal and morphological behavior of block and graft copolymers is a relatively new field of endeavor. It started in 1954, when F. M. Merrett fractionated mixtures of grafted na tural rubber with the corresponding homopolymers and observed that colloidal sols were formed at certain points during his fractional precipitations.

Author :
Publisher :
Page : 33 pages
File Size : 26,53 MB
Release : 2005
Category :
ISBN :

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For this project a number of new polymer materials were synthesized including trifunctional, tetrafunctional and hexafunctional regular graft copolymers. Additionally, a range of poly(cyclohexadiene) (PCHD) homopolymers and block copolymers containing PCHD blocks were prepared. The morphologies of the regular graft copolymers, and PCHD containing block copolymers were determined by TEM and SAXS. Additionally, the morphologies of cyclic block copolymers were studied and compared to their linear analogs. The tensile mechanical properties of the regular multigraft materials were studied and related to molecular architecture. It was found that increasing junction point functionality and increasing number of junction points per molecule increased strength and toughness, and decreased hysterysis. A series of block double graft (BDG) copolymers of unique molecular architecture were studied to relate molecular architecture to morphology and mechanical properties. The mechanical properties of some BDG materials compared favorably to commercial thermoplastic elastomers.

Author : L. H. Sperling
Publisher :
Page : 11 pages
File Size : 13,79 MB
Release : 1978
Category :
ISBN :

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The major accomplishments encompass four areas of research: (1) Controlled Grafting of Simultaneous Interpenetrating Polymer Networks. This research, which elucidated the relationship between polymer 1/polymer 2 compatibility and deliverately introduced graft sites, has now been accepted for publication by Polymer Science and Engineering. From an engineering point of view, the controlled morphology produced using epoxy/acrylic combinations yielded very tough, novel plastics. (2) Novel Staining Techniques for Saturated Two-Phased Polymers. Up till now, the only good staining technique for polyblends utilized an osmium tetroxide attack on polymer containg double bonds. The research under this contract showed how this method could be successfully extended to carboxyl or ester containing systems such as acrylics or methacrylics. (3) Polymer Blend and Interpenetrating Polymer Network Nomenclature. A major stumbling block in the development of multicomponent polymer systems has been an inadequate nomenclature. (4) The first experiments on decrosslinking of interpenetrating polymer networks was done under the auspices of this contract. Overall, significant progress was achieved in several areas of research. Several papers have either already appeared in print or will do so in the coming months.