The role of fast and slow processes in the formation of structure and properties of thermoplastic polyurethanes

2016 ◽  
Vol 18 (46) ◽  
pp. 31769-31776 ◽  
Author(s):  
D. V. Anokhin ◽  
M. A. Gorbunova ◽  
Ya. I. Estrin ◽  
V. V. Komratova ◽  
E. R. Badamshina

A new multi-blocked polyurethane-based thermoplastic elastomer was synthesized and characterized. A correlation between the supramolecular structure and mechanical properties was found.

2012 ◽  
Vol 627 ◽  
pp. 873-877
Author(s):  
Xiao Xia Jian ◽  
Le Qin Xiao ◽  
Wei Liang Zhou ◽  
Hai Qin Ding

The Semi-Interpenetrating Polymer Networks(Semi-IPNs) of poly(methyl methyacrylate/ethyl acrylate)(P(MMA/EA)) and polyurethane thermoplastic elastomer (PU) were synthesized by PU and copolymer of methyl methacrylate and ethyl acrylate to improve the compatibility of polymethyl methacrylate(PMMA) and PU Semi-IPNs . The structure and properties were investigated by Fourier transform infrared spectrometer, Solid nuclear magnetic resonance spectrometry, Dynamic mechanical thermal analysis and Mechanical properties. The tensile stress of (P(MMA/EA)/PU)( P(MMA/EA):PU=3:7) can get to 9.6MPa, the additional physical crosslinks and entanglement for Semi-IPNs are the reasons.


2018 ◽  
Vol 143 ◽  
pp. 02014 ◽  
Author(s):  
Viktoriya Guryeva ◽  
Alexander Doroshin ◽  
Yuliya Andreeva

At present, there is a trend towards increasing demand for ceramic products with enhanced physical and mechanical properties. This study is aimed at developing scientifically grounded compositions of ceramic products that maximize the use of local low-quality aluminosilicate raw materials and secondary raw materials in brick-making technology. Characteristics of local low-melting clays and industrial waste in the form of drilling slurry with minimum percentage of petroleum product were studied and presented in this paper. Standard methods for determining physical and mechanical properties of bricks, physicochemical and statistical methods of research are used as a methodological framework. The paper shows effects of drilling slurry with an increased content of calcium oxide on the composition, physical and mechanical properties of wall ceramics, as well as effects of composition of low-quality local clays and slurries on the structure and properties of ceramic materials. The modifying role of container glass and its effects on properties of a synthesized ceramic piece were studied and presented.


2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.


Symmetry ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 153 ◽  
Author(s):  
Christophe Humbert ◽  
Thomas Noblet

To take advantage of the singular properties of matter, as well as to characterize it, we need to interact with it. The role of optical spectroscopies is to enable us to demonstrate the existence of physical objects by observing their response to light excitation. The ability of spectroscopy to reveal the structure and properties of matter then relies on mathematical functions called optical (or dielectric) response functions. Technically, these are tensor Green’s functions, and not scalar functions. The complexity of this tensor formalism sometimes leads to confusion within some articles and books. Here, we do clarify this formalism by introducing the physical foundations of linear and non-linear spectroscopies as simple and rigorous as possible. We dwell on both the mathematical and experimental aspects, examining extinction, infrared, Raman and sum-frequency generation spectroscopies. In this review, we thus give a personal presentation with the aim of offering the reader a coherent vision of linear and non-linear optics, and to remove the ambiguities that we have encountered in reference books and articles.


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