Crystallizable Trans-Butadiene-Piperylene Elastomers

1978 ◽  
Vol 51 (5) ◽  
pp. 907-924 ◽  
Author(s):  
M. Bruzzone ◽  
A. Carbonaro ◽  
L. Gargani
Keyword(s):  
Glass Transition ◽  
Melting Point ◽  
Low Temperature ◽  
Temperature Sensitivity ◽  
General Purpose ◽  
Strain Sensitivity ◽  
Rational Utilization ◽  
Green Strength ◽  
Synthetic Rubber ◽  
Vanadium Based Catalysts

Abstract The synthesis of a crystallizable synthetic rubber based on butadiene and piperylene in the presence of active vanadium-based catalysts is described. This outlet for piperylene (a cocomponent with isoprene of the C5 cut of naphtha crackers) would allow a rational utilization of both monomers present in the same cut and draw the best advantage from the complementary properties of the copolymer described in this work and cis-1,4-polyisoprene. The butadiene units in the copolymer are in the trans-1,4-configuration. The piperylene content giving a good compromise between crystallization at low temperature (temperature sensitivity) and crystallization upon stretching (strain sensitivity) is 30 ± 5 mol%. The copolymer shows outstanding green strength and tack, and it is less prone than high-cis-polybutadiene and trans-polypentenamer to crystallization at low temperature, because of a particular combination of thermodynamic parameters. Among these, melting point and glass transition are somewhat adjustable by controlling the piperylene content in the range specified. The properties of this crystallizable rubber suggest its use as a general-purpose rubber, possibly in combination with other conventional elastomers.

AISI TYPE 302

Alloy Digest ◽  
1988 ◽  
Vol 37 (9) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Low Temperature ◽  
High Resistance ◽  
Heat Treating ◽  
General Purpose ◽  
Steel Mills ◽  
Temperature Performance ◽  
Aisi Type

Abstract AISI Type 302 is a general purpose austenitic chromium-nickel stainless steel. It has high resistance to corrosion and heat. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-99. Producer or source: Stainless steel mills. Originally published January 1960, revised September 1988.

Fully-physically crosslinked silk fibroin/poly(hydroxyethyl acrylamide) hydrogel with high transparency and adhesive properties for wireless sensing and low-temperature strain sensing

2021 ◽  
Vol 9 (6) ◽  
pp. 1880-1887
Author(s):  
Xia Sun ◽  
Shaoshuai He ◽  
Mengmeng Yao ◽  
Xiaojun Wu ◽  
Haitao Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Silk Fibroin ◽  
Temperature Sensing ◽  
Wireless Sensing ◽  
Strain Sensitivity ◽  
Strain Sensing ◽  
Adhesive Properties ◽  
High Transparency ◽  
Physically Crosslinked ◽  
Temperature Strain

Fully-physically crosslinked hydrogels with strain sensitivity and anti-freezing properties for wireless sensing and low temperature sensing were prepared.

scholarly journals Study on Performance Damage and Mechanism Analysis of Asphalt under Action of Chloride Salt Erosion

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3089
Author(s):  
Peilei Zhou ◽  
Wensheng Wang ◽  
Lili Zhu ◽  
Haoyun Wang ◽  
Yongming Ai
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
High Temperature ◽  
Low Temperature ◽  
Temperature Sensitivity ◽  
Salt Solution ◽  
Solution Concentration ◽  
Chloride Salt ◽  
Temperature Performance ◽  
Low Temperature Performance

This study aims to investigate the performance evolution and mechanism of asphalt under action of chloride salt erosion. Asphalt samples soaked with five different snow melting chloride salt concentrations were taken as the research object. Then, the high-temperature performance, low-temperature performance, temperature sensitivity and asphalt–aggregate adhesion property of asphalt samples were carried out. Additionally, Fourier transform infrared spectroscopy (FTIR) was used to explore the mechanism of chloride salt erosion on asphalt. Test results showed the linear variation relationships of high-temperature performance, low-temperature performance and temperature sensitivity with chloride salt concentrations. The high-temperature performance of asphalt would be improved by chloride snowmelt salt. With the increase in the chloride salt solution concentration, the low-temperature performance of asphalt became worse, and the temperature sensitivity increased. Moreover, after the effect of the chloride salt solution, the asphalt–aggregate adhesion property decreased with the increase in the chloride salt solution concentration. It is necessary to control the amount of chloride snowmelt salt in the actual snow removal projects. Finally, based on Fourier transform infrared spectroscopy, the mechanism of chloride salt erosion on asphalt was preliminarily explored. With the increase in the chloride salt solution concentration, the proportion of light components (saturated fraction, aromatic fraction) in asphalt decreased, and the proportion of heavy components (resin and asphaltene) with good thermal stability increased.

Fiber interferometry with low temperature sensitivity

2020 ◽  
Author(s):  
Zitong Feng ◽  
Vincent Michaud-Belleau ◽  
Jayanta K. Sahu ◽  
Johan Nilsson ◽  
Christophe A. Codemard ◽  
...  
Keyword(s):  
Low Temperature ◽  
Temperature Sensitivity

Facile synthesis of high‐melting point spherical TiC and TiN powders at low temperature

2019 ◽  
Vol 103 (2) ◽  
pp. 889-898 ◽  
Author(s):  
Maoqiao Xiang ◽  
Miao Song ◽  
Qingshan Zhu ◽  
Chaoquan Hu ◽  
Yafeng Yang ◽  
...  
Keyword(s):  
Melting Point ◽  
Low Temperature ◽  
High Melting ◽  
High Melting Point ◽  
Facile Synthesis

Microwave-Vacuum Integrated Cavity with a Low Temperature Sensitivity for Cs Fountain Clocks

2021 ◽  
Author(s):  
Fasong Zheng ◽  
Fang Fang ◽  
Weiliang Chen ◽  
Kun Liu ◽  
Shaoyang Dai ◽  
...  
Keyword(s):  
Low Temperature ◽  
Temperature Sensitivity

Strong Liquid Behavior of Zr-Ti-Cu-Ni-Be Bulk Metallic Glass Forming Alloys

1996 ◽  
Vol 455 ◽  
Author(s):  
Ralf Busch ◽  
Andreas Masuhr ◽  
Eric Bakke ◽  
William L. Johnson
Keyword(s):  
Glass Transition ◽  
Melting Point ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Supercooled Liquid ◽  
Glass Transition Region ◽  
Glass Forming ◽  
Liquid Behavior ◽  
Metallic Liquids ◽  
Microscopic Origin

ABSTRACTThe viscosities of the Zr46.75Ti8.25Cu7.5Ni10Be27.5 and the Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass forming liquids was determined from the melting point down to the glass transition in the entire temperature range of the supercooled liquid. The temperature dependence of the viscosity in the supercooled liquid obeys the Vogel-Fulcher-Tammann (VFT) relation. The fragility index D is about 20 for both alloys and the ratio between glass transition temperature and VFT temperature is found to be 1.5. A comparison with other glass forming systems shows that these bulk metallic glass formers are strong liquids comparable to sodium silicate glass. Furthermore, they are the strongest among metallic glass forming liquids. This behavior is a main contributing factor to the glass forming ability since it implicates a higher viscosity from the melting point down to the glass transition compared to other metallic liquids. Thus, the kinetics in the supercooled liquid is sluggish and yields a low critical cooling rate for glass formation. The relaxation behavior in the glass transition region of the alloys is consistent with their strong glassy nature as reflected by a stretching exponent that is close to 0.8. The microscopic origin of the strong liquid behavior of bulk metallic glass formers is discussed.

Elastomer Structures and ‘Cold Crystallization’

1979 ◽  
Vol 52 (1) ◽  
pp. 207-212 ◽  
Author(s):  
M. Bruzzone ◽  
E. Sorta
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Melting Point ◽  
Natural Rubber ◽  
Crystallization Rate ◽  
Cold Crystallization ◽  
Structural Defects ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Abstract In a great number of applications an ideal elastomer should satisfy, to a certain extent, both of the following requirements: (1) nearly instantaneous crystallization upon application of strain (strain induced crystallization) and (2) slow or no crystallization when cooled at the temperature of maximum crystallization rate (cold induced crystallization). A noteworthy case of (2) is elastomer crystallization in a strained state. The connection between the points (1) and (2) has not been clearly understood up to now, but it is known that some crystallizable elastomers fulfil the requirements of both (1) and (2) better than others. From an experimental point of view, cold induced crystallization kinetics are substantially easier to measure than those of very fast strain induced crystallization. The phenomenon of cold induced crystallization in natural rubber, NR, has been known since the very beginning of elastomer technology and the tendency of natural rubber to crystallize by cooling has been overcome by crosslinking it with sulphur (vulcanization) without impairing its ability to crystallize by stretching (Goodyear, 1836). The synthesis of cis-polyisoprenes (IR) and cis-polybutadiene (BR) of different microstructural purity (different cis content) gave the possibility of changing the crystallization rate. It has also been reported that the very fast cold crystallization of trans-polypentenamer (TPA) could be reduced by lowering the trans content. The same fact had been observed earlier for trans-polychloroprene. There is a general agreement in postulating that the reduction of the crystallization rate, obtained either by cross-linking or by chain regularity reduction, can be linked with the lowering of the melting point. In both cases the low level of structural defects introduced in the chains does not affect the glass transition temperature in such a way as to vary the crystallization rate. The aim of this paper is to emphasize the importance of the variations of the glass transition temperature and melting point on the elastomeric cold crystallization rate and the way these may be used in planning new elastomer structures.

Thermal Analysis of Nomex® and Kevlar® Fibers

1977 ◽  
Vol 47 (1) ◽  
pp. 62-66 ◽  
Author(s):  
J. R. Brown ◽  
B. C. Ennis
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Glass Transition ◽  
Melting Point ◽  
Transition Region ◽  
High Temperatures ◽  
High Performance ◽  
Polymer Melt ◽  
Glass Transition Region ◽  
Dta Curves

DTA, TG, and TMA curves of commercial Kevlar® 49 and Nomex® fibers have been used to assess their behavior at high temperatures. The fibers lost absorbed water around 100°C, and a glass transition was reflected in the DTA and TMA curves in the region of 300°C. Difficulties in the interpretation of DTA and TMA curves in the glass-transition region and in the assignments of Tv‘s for these high-performance fibers are discussed. Whereas Kevlar 49 showed both a crystalline melting point (560°C) and a sharp endothermal thermal decomposition (590°C), Nomex showed only the latter (440°C) and no evidence of melting from the DTA curves. The endothermal decomposition peaks apparently correspond to “polymer melt temperatures” reported for related materials, and correlate well with the TG and TMA features. During thermal analysis of Kevlar 49, oxidation occurs more readily than thermal decomposition, but the latter predominates for Nomex. Differences between dyed and undyed Nomex were due to differences in yarn constitution.

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