Download or read book Synthesis and Mechanical Properties of Radiation cured Acrylo urethane Elastomers and Their Structural and Morphological Features written by Mahmoud Ashour Khamis and published by . This book was released on 1984 with total page 502 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 Polymer Yearbook written by Richard A. Pethrick and published by CRC Press. This book was released on 1987 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains reviews on state-of-the-art Japanese research presented in the annual Spring and Autumn meetings of the Japanese Polymer Science Society. The aim of this section is to make information on the progress of Japanese Polymer Science, and on topics of current interest to polymer scientists in Japan, more easily available worldwide.
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1984 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1985 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer Yearbook written by Richard Arthur Pethrick and published by . This book was released on 1984 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindex written by and published by . This book was released on 1986 with total page 1634 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1989 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermoplastic Elastomers written by N. R. Legge and published by . This book was released on 1987 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Morphology and Mechanical Properties of Radiation Polymerized Urethane Acrylates written by Lachhman Hassanand Wadhwa and published by . This book was released on 1980 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Elastomers II written by P. M. Visakh and published by Springer Science & Business Media. This book was released on 2013-04-09 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the second volume of a two-volume work which summarizes in an edited format and in a fairly comprehensive manner many of the recent technical research accomplishments in the area of Elastomers. “Advances in Elastomers” discusses the various attempts reported on solving these problems from the point of view of the chemistry and the structure of elastomers, highlighting the drawbacks and advantages of each method. It summarize the importance of elastomers and their multiphase systems in human life and industry, and covers all the topics related to recent advances in elastomers, their blends, IPNs, composites and nanocomposites. This second volume is deals with composites and nanocomposites of elastomers.
Download or read book All Acrylic Based Thermoplastic Elastomers written by Wei Lu (Chemist) and published by . This book was released on 2017 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermoplastic elastomers (TPEs) have been widely studied because of their recyclability, good processability, low production cost and distinct performance. Compared to the widely-used styrenic TPEs, acrylate based TPEs have potential advantages including exceptional chemical, heat, oxygen and UV resistance, optical transparence, and oil resistance. However, their high entanglement molecular weight lead to "disappointing" mechanical performance as compared to styrenic TPEs. The work described in this dissertation is aimed at employing various approaches to develop the all acrylic based thermoplastic elastomers with improved mechanical performance. The first part of this work focuses on the introduction of acrylic polymers with high glass transition temperatures. Poly(1-adamantyl acrylate) (PAdA) was studied including the anionic polymerization, molecular information, thermal properties, unperturbed chain dimensions and chain flexibility. The homopolymers exhibit a high glass transition temperature (133 °C) and decomposition temperature (376 °C). The polymer chain exhibits a comparable persistence length, diameter per bead, and characteristic ratio to those of poly(methylmethacrylate) and polystyrene. The outstanding properties of PAdA were utilized by the cooperation with poly(tetrahydrofurfuryl acrylate) (PTHFA) to make the PAdA-b-PTHF-b-PAdA (ATA) triblock copolymers. The resulting polymer showed distinct microphase separation behaviors and an upper service temperature at 123 °C, which is higher than that of both conventional styrenic TPEs and acrylic TPEs. The ATA triblock copolymers exhibited mechanical strength and elongation higher than those of commercial all acrylic TPEs. The second part involves the synthesis of poly(butyl acrylate)-g-poly(methylmethacrylate) (PBA-g-PMMA) graft copolymers. Secondary-butyl lithium/N-isopropyl- 4-vinylbenzylamine (sec-BuLi/PVBA) initiation system was used to synthesize the PMMA macromonomer by anionic polymerization. By the combination of enhanced molecular weight and complex architecture, the resulting polymer showed exceptional microphase separation behavior, extraordinary mechanical strength and superelastomer characteristics with greatly improved elongation and exceptional recovery behavior. In the final chapter, other approaches to improve the mechanical properties of all acrylic based TPEs are discussed and prospected, including the introduction of extra driving forces, and the possible combination routes of all the approaches attempted. In addition, the great potential of PVBA to build complex architectures is proposed, including triarm stars, multigraft copolymers with tetrafuntional branch points, four arm stars and H-shaped copolymers.
Download or read book Current Topics in Elastomers Research written by Anil K. Bhowmick and published by CRC Press. This book was released on 2008-05-07 with total page 1105 pages. Available in PDF, EPUB and Kindle. Book excerpt: From weather-proof tires and artificial hearts to the o-rings and valve seals that enable successful space exploration, rubber is an indispensable component of modern civilization. Stiff competition and stringent application requirements foster continuous challenges requiring manufacturers to fund ever-expanding research projects. However, this vas
Download or read book Elastomers for Use in Radiation Fields written by Robert Harrington and published by . This book was released on 1960 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Elastomers written by Kohudic MELVYN and published by CRC Press. This book was released on 1994-07-01 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a Structure property Correlation for Castable Urethane Elastomers written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A significant problem in electronic encapsulation is the poor load bearing performance of existing replacements for Adiprene-MOCA urethane elastomer. In response to this problem, this study defines the structural features that control the viscoelastic properties of the following liquid castable elastomers: Adiprene-MOCA, EN-7, and 3121-S.A review of previous investigations on a related class of materials suggests that viscoelastic properties may be more directly related to the physical structure or morphology of these elastomers, rather than their chemical structure. Accordingly, the morphology of the subject elastomers is characterized by means of electron microscopy and x-ray scattering measurements. These measurements reveal that within each elastomer incompatible chain segments cluster into separate domains, or microphases on a scale of 10 +- 1 nm. On this basis, it is concluded that the two major thermomechanical transitions present in each elastomer can be assigned to separate transitions within the two microphases. The above-ambient transition, which determines the upper use temperature of the elastomer, is specifically assigned to the glass transition of an amorphous microphase. The significance of this structure-property correltion for the liquid castable elastomers is twofold: (1) it permits generalization of mechanical property measurements on existing materials in order to predict their performance in unusual applications and (2) it leads to a rational strategy for developing improved elastomers for new, more demanding applications.
Download or read book Engineered Materials Abstracts written by and published by . This book was released on 1995 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt:
