Modification of Asphalt by Block Polymers of Butadiene and Styrene

1982 ◽  
Vol 55 (5) ◽  
pp. 1389-1402 ◽  
Author(s):  
Gerard Kraus
Keyword(s):  
Molecular Weight ◽  
Low Temperature ◽  
Physical Properties ◽  
Room Temperature ◽  
Softening Temperature ◽  
Block Polymers ◽  
Rich Phase ◽  
Block Polymer ◽  
Low Concentrations ◽  
Low Temperature Flexibility

Abstract Elastomeric thermoplastic block polymers of butadiene and styrene are highly effective in converting asphalts into truly rubber-like materials. Additions of 10–14% of these polymers to asphalt result in lower penetration values, greatly reduced flow above room temperature, increases in softening temperature to values in excess of 100°C and superior low temperature flexibility. The blends are characterized by a unique morphology in which the block polymer, swollen with the lower molecular weight constituents of the asphalt, forms a continuous lacework in a bituminous phase enriched with asphaltenes. The polymer-rich phase consists, in turn, of two microphases derived from the block polymer domain structure. At low concentrations, where the swollen polymer forms discrete inclusions in the asphaltic continuum, effects on the physical properties of the asphalt are less pronounced but can still be significant. The multiphase morphology of these composites accounts satisfactorily for the most important features of their mechanical behavior.

Effect of FCC Slurry on Performance of SBS Modified Bitumen

2020 ◽  
Vol 993 ◽  
pp. 1361-1366
Author(s):  
Tian Wei Zhang ◽  
Jian Xin Li ◽  
San Peng Mao ◽  
Gui Tao Zheng ◽  
Jian Ying Yu
Keyword(s):  
Low Temperature ◽  
Physical Properties ◽  
Catalytic Cracking ◽  
Softening Point ◽  
Petrochemical Industry ◽  
Fluorescence Microscope ◽  
Fluid Catalytic Cracking ◽  
Modified Bitumen ◽  
Low Temperature Flexibility

Fluid catalytic cracking (FCC) slurry is a by-product of petrochemical industry rich in aromatics. In this paper, the effect of FCC slurry on the physical properties of SBS modified bitumen was investigated by softening point, penetration, ductility and low temperature flexibility test. The influence of FCC slurry on the compatibility of SBS modified bitumen was evaluated by fluorescence microscope and segregation test. The results show that FCC slurry improves the softening point, penetration, ductility and low temperature flexibility of SBS modified bitumen. Fluorescence microscope showed that FCC slurry promotes the dispersion of SBS in bitumen, which is conducive to the formation of network crosslinking structure of SBS modified bitumen. The segregation test indicated that the compatibility of SBS with bitumen was improved with the content of FCC slurry increasing.

The Interaction of Sulfur and Sulfur Compounds with Olefinic Substances. VII. Low-Temperature Sulfuration of Trialkylethylenes with Hydrogen Sulfide-Sulfur Dioxide and with a Sulfur-Zinc Dithiocarbamate System

1955 ◽  
Vol 28 (2) ◽  
pp. 470-479
Author(s):  
E. H. Farmer ◽  
J. F. Ford ◽  
J. A. Lyons
Keyword(s):  
Zinc Oxide ◽  
Hydrogen Sulfide ◽  
Sulfur Dioxide ◽  
Low Temperature ◽  
Room Temperature ◽  
Cross Linking ◽  
Sulfide Sulfur ◽  
Tetramethylthiuram Disulfide ◽  
Zinc Compounds ◽  
Low Concentrations

Abstract The sulfuration of trialkylethylenes with hydrogen sulfide-sulfur dioxide at 0° C (Peachey process) results in disubstitutive cross-linking of the olefins, yielding dialkenyl tetrasulfides. At higher temperatures, substitutive-additive cross-linking occurs, and alkyl alkenyl polysulfides are formed. Dialkenyl tetrasulfides are similarly formed by causing the olefin to react with sulfur at room temperature in the presence of zinc oxide and zinc dibutyldithiocarbamate, low concentrations of hydrogen sulfide acting as a catalyst for this reaction. At higher temperatures, the reaction is also exclusively disubstitutive, a feature connected with the function of zinc compounds in influencing the cross-linking reaction. The sulfuration of olefins with tetramethylthiuram disulfide at 140° C shows a similar influence of zinc compounds.

Crystallization in Unstretched Rubber. Microscopic Study in Polarized Light

1951 ◽  
Vol 24 (3) ◽  
pp. 550-556
Author(s):  
H. N. Campbell ◽  
M. D. Allen
Keyword(s):  
Low Temperature ◽  
Physical Properties ◽  
Melting Temperature ◽  
Microscopic Study ◽  
Room Temperature ◽  
Polarized Light ◽  
X Ray Diffraction ◽  
X Ray ◽  
Limited Mobility ◽  
Sensitive Method

Abstract Since many elastomers indicate by their physical properties that crystallization occurs even when such crystallization is not detectable by x-ray diffraction, a direct microscopic study in polarized light was undertaken. This study confirms the presence of such crystallinity not only in rubber but also in polybutadiene and some low-temperature copolymers. Furthermore, the same crystal pattern is reproduced on melting and refreezing provided the intermediate melting temperature is not too high. This indicates that x-ray diffraction is not a very sensitive method for detecting small amounts of crystallinity in high polymers. The reproduction of the crystal pattern on refreezing shows that the molecular segments have limited mobility even at room temperature; this may require revision of current theories of the origin of retractive forces in elastomers.

Trihapto cycloheptatrienyl molybdenum and tungsten dicarbonyl compounds incorporating tridentate chelating dimethyl(1-pyrazolyl)(ethanolamine)gallate ligands

1980 ◽  
Vol 58 (21) ◽  
pp. 2278-2285 ◽  
Author(s):  
Kenneth S. Chong ◽  
Alan Storr
Keyword(s):  
Nitrogen Atom ◽  
Low Temperature ◽  
Physical Properties ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Amino Nitrogen ◽  
Nmr Studies ◽  
Dicarbonyl Compounds ◽  
H Nmr ◽  
And Tungsten

The synthesis and physical properties of a series of cycloheptatrienyl molybdenum and tungsten dicarbonyl compounds incorporating dimethyl(1-pyrazolyl)(ethanolamine)gallate ligands have been investigated. The monomeric, pseudo octahedral, complexes have the organogallate ligand occupying a set of facial positions with the cycloheptatrienyl ring situated opposite to the amino nitrogen atom. Proton nmr studies have shown the η3-C7H7 ligand of the complexes to be fluxional in solution at room temperature. In the low temperature limiting 1H nmr spectra of the complexes in solution, however, it is possible to distinguish ail seven protons of the static η3-C7H7 ring owing to the asymmetric nature of the octahedral molecules.

COPPER ALLOY No. 803

Alloy Digest ◽  
1979 ◽  
Vol 28 (4) ◽  
Keyword(s):  
Electrical Conductivity ◽  
Corrosion Resistance ◽  
Elevated Temperature ◽  
Physical Properties ◽  
Copper Alloy ◽  
Room Temperature ◽  
Heat Treating ◽  
Softening Temperature ◽  
Good Combination ◽  
Room Temperature Strength

Abstract Copper No. 803 is cast copper containing silver to raise its softening temperature and improve its elevated-temperature properties. It has low room-temperature strength with medium-to-good ductility. It is characterized by a good combination of thermal and electrical conductivity and is resistant to corrosion. These characteristics make it highly suitable for many applications requiring good conductivity and/or corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: Cu-370. Producer or source: Copper alloy foundries.

New Thermoplastic Elastomers. Styrene Grafts on Lithiated Polydienes and Their Hydrogenated Counterparts

1973 ◽  
Vol 46 (4) ◽  
pp. 1044-1054 ◽  
Author(s):  
J. C. Falk ◽  
R. J. Schlott ◽  
D. F. Hoeg ◽  
J. F. Pendleton
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Room Temperature ◽  
Graft Copolymers ◽  
Gel Permeation Chromatography ◽  
Thermoplastic Elastomers ◽  
Proper Choice ◽  
Melt Flow ◽  
Gel Permeation ◽  
Poly Ethylene

Abstract Metalation of diene polymers such as poly (butadiene) and poly(isoprene) with sec-butyllithium and tetramethylethylenediamine in cyclohexane at room temperature forms lithiated polydienes. Reaction of the polylithiodienes with styrene or α-methylstyrene forms graft copolymers. The extent of metalation is much greater than previously reported metalations with n-butyllithium and tetramethylethylenediamine. The grafting efficiencies, determined by acetone extraction and gel permeation chromatography, are greater than 95 per cent. Graft copolymers of poly (styrene) on EPDM rubbers may also be prepared using this technique. The physical properties of the graft copolymers are a function of molecular weight, graft site level, and composition. Products at specific compositions and graft levels are thermoplastic elastomers. Their properties are comparable to SBS rubbers, and offer as an advantage high melt flow. Graft copolymers of poly(styrene) on poly(ethylene) and poly(ethylene-co-butene-1) result from the hydrogenation of the butadiene moeities of graft copolymers of poly (styrene) on 1,4-poly(butadiene) and 1,2 and 1,4-butadiene copolymers, respectively. Complete hydrogenation results in graft copolymers of poly(vinylcyclohexane) on poly(ethylene) and on poly(ethylene-co-butene-1). In both of these cases thermoplastic elastomers result if the proper choice of composition and graft level is made.

Heat Conductivity of Rubber at Low Temperatures

1940 ◽  
Vol 13 (4) ◽  
pp. 830-830
Author(s):  
Adolf Schallamach
Keyword(s):  
Low Temperature ◽  
Physical Properties ◽  
Temperature Region ◽  
Heat Conductivity ◽  
Low Temperatures ◽  
Room Temperature ◽  
Tire Rubber ◽  
Order Of Magnitude ◽  
Temperature Work

Abstract While examining the possibilities of applying rubber in low temperature work, we were hampered by the lack of available data on its physical properties at low temperatures. We were aware of the difficulties to be expected in making accurate measurements in that temperature region, and this applied especially to the heat conductivity, in which we were particularly interested. To obtain at least an estimate of the order of magnitude, we carried out some measurements of the heat conductivity of commercial rubber (North British tire rubber) at room temperature and at the temperature of liquid air.

A New Investigation of Tetrahydrofuran-Based Polyether Glycols in Urethane Elastomers

1980 ◽  
Vol 53 (5) ◽  
pp. 1032-1040 ◽  
Author(s):  
E. Pechhold ◽  
G. Pruckmayr ◽  
I. M. Robinson
Keyword(s):  
Low Temperature ◽  
Physical Properties ◽  
Room Temperature ◽  
Hydrolytic Stability ◽  
Cyclic Ether ◽  
The Other ◽  
Temperature Behavior ◽  
Oil Resistance ◽  
Soft Segments ◽  
Better Than

Abstract Random copolyether glycols with 50 mole % EO and low cyclic ether content represent novel soft segments for polyurethanes, and have some advantages over the other soft segments as shown in Table V. THF/EO copolyether glycols are easier to handle and to process because they are liquids at room temperature and exhibit lower viscosities and better diol compatibility. Physical properties of polyurethanes made from THF/EO copolyether glycols are comparable to those made from other soft segments; the hydrolytic stability and low temperature behavior are superior to polyester and polycaprolactone glycols, and solvent/oil resistance is better than PTMEG. THF/EO copolyether glycol is a replacement for PTMEG only with reformulation; it could be considered for applications which require better solvent/oil resistance or easier handling and processability.

COPPER ALLOY No. C80500

Alloy Digest ◽  
1986 ◽  
Vol 35 (3) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Elevated Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Copper Alloy ◽  
Room Temperature ◽  
Heat Treating ◽  
Softening Temperature ◽  
Corrosion And Oxidation ◽  
Room Temperature Strength

Abstract Copper No. C80500 is cast copper containing silver to raise its softening temperature and improve its elevated-temperature properties. It is deoxidized with boron. It has low room-temperature strength with medium-to-good ductility. It has good thermal and electrical conductivies and is resistant to corrosion and oxidation. These characteristics make it highly suitable for applications that require good conductivity and resistance to corrosion and oxidation. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: Cu-507. Producer or source: Copper alloy foundries.

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