Download or read book Structure Property Relationships in Thermoplastic Elastomers III Segmented Polyacetal Polyurethanes written by J. C. W. Chien and published by . This book was released on 1985 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dihydroxy terminated polyacetals had been synthesized from aldehydes and glycols and used as soft segments to obtain segmented polyurethane block copolymers. The glass transition temperature (T sub G) of PacPU with 1,350 M sub n polyacetals is raised to -38 C and none was observed for shorter polyacetal chains. The copolymers can be synthesized to have a broad range of mechanical properties such as modulus from 0.5 to 130 MPa, stress at break from 0.7 to 21 MPa and elongation at break from 66% to 1300% through the variation of the constituents and composition. The rheological properties are only slightly dependent on temperature for symmetrical diisocyanates but quite temperature sensitive with asymmetrical diisocyanate copolymers. The polyacetals aere selected to build in acid catalyzed thermal decomposition of the thermoplastic elastomers. The hard and soft segments have TGA decomposition peaks at 292 and 343 C, respectively. Most copolymers display 2 peaks at temperatures between these two limits.

Download or read book Structure Property Relationships in Thermoplastic Elastomers I Segmented Polyether Polyurethanes written by E. J. Woo and published by . This book was released on 1984 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: Segmented poly(ether-b-urethanes) have been synthesized with 2000 MW polypropylene oxide coupled with diisocyanates and diol type chain extenders. The diisocyanates used were symmetric rigid 4,4'-diphenylmethane diisocyanate (MDI), linear aliphatic hexamethylene diisocyanate (HDI) and unsymmetric rigid toluene-2,4-diisocyanate (TDI). The chain extenders were symmetric N, N'-bis(2-hydroxyethyl) terephthalamide (BT) and N, N'-bis(2-hydroxyethyl)-hydroquinone (BH) unsymmetric N, N'-bis(2-hydroxyethyl)isophthalamide, and linear aliphatic butanediol. Hard segment contents ranged from 20 to 40 wt %. The thermal behavior of these materials is consistent with phase separation into separate hard and soft domains.

Download or read book Structure property Relationships in Solid Polymers written by Zohar H. Ophir and published by . This book was released on 1979 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1985 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Drexel Polymer Notes written by and published by . This book was released on 1989 with total page 1094 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structure property Relationships of Chain extended Thermoplastic Polyurethane Elastomers written by Paul A. Sykes and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polyurethane Elastomers written by Cristina Prisacariu and published by Springer Science & Business Media. This book was released on 2011-07-03 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive account of the physical / mechanical behaviour of polyurethanes (PU ́s) elastomers, films and blends of variable crystallinity. Aspects covered include the elasticity and inelasticity of amorphous to crystalline PUs, in relation to their sensitivity to chemical and physical structure. A study is made of how aspects of the constitutive responses of PUs vary with composition: the polyaddition procedure, the hard segment, soft segment and chain extender (diols and diamines) are varied systematically in a large number of systems of model and novel crosslinked andthermoplastic PUs. Results will be related to: microstructural changes, on the basis of evidence from x-ray scattering (SAXS and WAXS), and also dynamic mechanical analyses (DMA), differential scanning calorimetry (DSC) and IR dichroism. Inelastic effects will be investigated also by including quantitative correlations between the magnitude of the Mullins effect and the fractional energy dissipation by hysteresis under cyclic straining, giving common relations approached by all the materials studied. A major structural feature explored is the relationship between the nature of the hard segment (crystallising or not) and that of the soft segments. Crystallinity has been sometimes observed in the commercial PUs hard phase but this is usually limited to only a few percent for most hard segment structures when solidified from the melt. One particular diisocyanate, 4,4’-dibenzyl diisocyanate (DBDI) that, in the presence of suitable chain extenders ( diols or diamines), gives rise to significant degrees of crystallinity [i-iii] and this is included in the present work. Understanding the reaction pathways involved, in resolving the subtle morphological evolution at the nanometre level, and capturing mathematically the complex, large-deformation nonlinear viscoelastic mechanical behaviour are assumed to bring new important insights in the world basic research in polyurethanes and towards applied industrial research in this area.

Download or read book Structure Property Relationships in Thermoplastic Elastomers IV Dynamic Mechanical Relaxations in Poly Dioxolane Poly Butyltrioxocane and Poly Propylene Oxide Polyurethanes written by James C. Chen and published by . This book was released on 1987 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamic mechanical measurements had been made on polyurethanes of a range of hard segment content (HSC) obtained form alpha, omega-dihydroxy derivatives of poly(propylene oxide) of 2000 to 12,000 MW coupled with MDI and TDI with hydroxyethyl phthalamide chain extenders. N-methylated chain extender was used to investigate the effect of hydrogen bonding. A board gamma transition was observed between - 100 deg and -115 deg attributable to the local motion of methylene sequences with a distribution of relaxations. The B transition between -55 deg and -72 deg is influenced by the degree of hydration; the a transition occurs at nearly the same temperatures for all the TPE's independent of HSC and thermal history. The magnitude of the loss tangent peak corresponds to the glass transition. An alpha transition at higher temperature is sensitive to the structure of soft segment, HSC and thermal history.

Download or read book Structure property Relationships in Polyurethane Elastomers written by Joseph John Marcinko and published by . This book was released on 1992 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structure property Relationships in Some Linear Thermoplastic Urethane Block Copolymer Elastomers written by M. B. Heard and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structure property Relationships in Polymer polyols Based Polyurethane Elastomers written by Nabil Abdulkader Saleh and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigating the Structure property Relationships in Thermoplastic Elastomers and Polymers for Explosion resistant Coatings written by Stephanie Ilana Rosenbloom and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the relationship between a polymer's molecular structure and its bulk properties (i.e., mechanical and morphological behaviors) is necessary for the design of next-generation materials with targeted properties. In this vein, we have developed methods to alter and probe the influence of polymer composition on the material properties of two high-value products-thermoplastic elastomers (TPEs) and polyurea (PU). By systematically varying the molecular weight distribution shape in TPEs, we were able to precisely determine the role of chain length composition on the mechanical and morphological properties. Furthermore, by developing an experimental protocol for in-situ structural characterization using X-ray scattering techniques, we were able to elucidate the influence of polymer composition on PU materials under high-pressure conditions. These experimental methods have clearly demonstrated the value of understanding structure-property relationships in TPEs and PU-based materials, particularly how polymer composition can be used as a handle to predictably tune polymer properties.

Download or read book Study of the Structure property Relationships in Polyurethane Elastomers Derived from a Biosourced Polyol written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermoplastic Elastomers written by J. A. Brydson and published by iSmithers Rapra Publishing. This book was released on 1995 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nature and general properties of TPE's are explained, and the classes of materials considered in turn include styrenic block copolymers, polyether-esters, polyamides, polyurethanes, polyolefins and other miscellaneous systems. Developments in specific market sectors are also outlined. The review is supported by an extensive References and Abstracts section, containing over 400 abstracts, which provide a great deal more information on these useful materials.

Download or read book Morphology and Fatigue Properties of Polyurethane Thermoplastic Elastomers written by Craig Wayne Stephen Myers and published by . This book was released on 1993 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polyurethane thermoplastic elastomers are segmented block polymers consisting of rubbery "soft" blocks and glassy or semi-crystalline "hard" blocks. Thermodynamic incompatibility between the soft and hard blocks causes the formation of a microdomain morphology which imparts elastomeric properties to the material. Despite their commercial importance, the response of these materials to repeated cyclic loading (fatigue) has not been well studied. This work is devoted to achieving a more detailed understanding of the chemical and morphological factors which govern fatigue behavior in polyurethane thermoplastic elastomers.

Download or read book Dokumentation Rheologie written by and published by . This book was released on 1986 with total page 1158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of the Structure property Relationships in Polyurethane Elastomers Derived from a Biosourced Polyol written by Anne-Cécile Mortamet and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: