Polysulfide Liquid Polymers

1951 ◽  
Vol 24 (3) ◽  
pp. 724-735
Author(s):  
J. S. Jorczak ◽  
E. M. Fettes
Keyword(s):  
Molecular Weight ◽  
Diffusion Rate ◽  
Service Temperature ◽  
Good Resistance ◽  
Resistance To Oxidation ◽  
Wide Range ◽  
Liquid Polymers ◽  
Milling Equipment ◽  
Rubber State ◽  
Polysulfide Polymers

Abstract Polysulfide liquid polymers are a comparatively recent development conceived at the Thiokol Laboratories in 1943. The development was initiated by the problem of finding methods to reduce the molecular weight of a polysulfide rubber which was too tough to process on conventional rubber milling equipment. The problem was solved by reduction of a few of the disulfide links present in the polymer chain. It was soon found that the method was applicable to the preparation of polymers low enough in molecular weight to be liquids. The method produces dithiols of high purity which are extremely active in a wide variety of chemical reactions. Some formulations have been developed which depend on conversion from the liquid to rubber state at temperatures as low as 50° F in about 30 minutes. Most of the converting agents function through oxidation with hydrogen removal from the thiol and a linkage of sulfurs to reform the disulfide group. The converted polymers have the general properties of polysulfide polymers: good solvent resistance to a wide range of solvents, low diffusion rate of gases, good resistance to oxidation, ozone, and weathering, and a service temperature range from −65° to +250° F. (Some compounds can withstand intermittent temperatures as high as +350° F.) The low temperature properties are inherent in the polymer and do not depend on special compounding techniques.

Polysulfide Polymers

1951 ◽  
Vol 24 (3) ◽  
pp. 709-723
Author(s):  
E. M. Fettes ◽  
J. S. Jorczak
Keyword(s):  
Molecular Weight ◽  
Stress Relaxation ◽  
Cross Linking ◽  
Condensation Polymerization ◽  
Solvent Resistance ◽  
Polymer Properties ◽  
End Groups ◽  
Different Types ◽  
Liquid Polymers ◽  
Polysulfide Polymers

Abstract The chemistry of the condensation polymerization is reviewed briefly. The structures of the polymeric products as well as the effects of copolymerization, cross-linking, end groups, and molecular weight upon polymer properties are discussed. The composition and properties of the commercial crude rubbers, water dispersions, and liquid polymers are presented together with ideas on the mechanism of their vulcanization. The reason for the odor of polysulfide polymers is discussed. Some information is presented on solvent resistance, stress relaxation, and other characteristics of the polymers. Applications for the different types of products are summarized.

COPPER ALLOY No. 268

Alloy Digest ◽  
1976 ◽  
Vol 25 (2) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Copper Alloy ◽  
Cold Working ◽  
Heat Treating ◽  
Zinc Alloy ◽  
Good Resistance ◽  
Wide Range ◽  
Copper Zinc ◽  
The Common ◽  
Cold Worked

Abstract Copper Alloy No. 268 is a copper-zinc alloy with excellent cold-working properties and good resistance to corrosion. It can be cold worked by all the common fabrication processes and has a wide range of applications. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-306. Producer or source: Brass mills.

UNS N09706

Alloy Digest ◽  
1989 ◽  
Vol 38 (2) ◽  
Keyword(s):  
High Strength ◽  
Heat Treating ◽  
Chromium Alloy ◽  
Good Resistance ◽  
Nickel Iron ◽  
Temperature Performance ◽  
Resistance To Oxidation ◽  
Oxidation And Corrosion ◽  
Iron Chromium Alloy ◽  
Iron Chromium

Abstract UNS N09706 is a precipitation-hardenable, nickel-iron-chromium alloy with high strength at temperatures to 1200 F and with good resistance to oxidation and corrosion over a broad range of temperatures and environments. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-368. Producer or source: Nickel and nickel alloy producers.

NICROFER 6023

Alloy Digest ◽  
1985 ◽  
Vol 34 (5) ◽  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Iron Alloy ◽  
Heat Treating ◽  
Chemical Equipment ◽  
Good Resistance ◽  
Nickel Chromium ◽  
Power Plant Equipment ◽  
Resistance To Oxidation ◽  
Plant Equipment

Abstract NICROFER 6023 is a nickel-chromium-iron alloy containing small quantities of aluminum. It has excellent resistance to oxidation at high temperatures, good resistance in oxidizing sulfur-bearing atmospheres and good resistance to carburizing conditions. The alloy has good mechanical properties at room and elevated temperatures. Its applications include heat treating furnace equipment, chemical equipment in various industries, and power plant equipment. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-314. Producer or source: Vereingte Deutsche Metallwerke AG.

NICROFER 7216 H

Alloy Digest ◽  
1997 ◽  
Vol 46 (1) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Stress Corrosion Cracking ◽  
Iron Alloy ◽  
Heat Treating ◽  
Good Resistance ◽  
Nickel Chromium ◽  
Solution Treated ◽  
Resistance To Oxidation ◽  
Resistance To Stress

Abstract Nicrofer 7216 H is a solution-treated nickel-chromium-iron alloy with good resistance to oxidation, carburization, and nitriding; good resistance to stress-corrosion cracking; and good resistance to dry chlorine and hydrogen chloride. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-520. Producer or source: VDM Technologies Corporation.

NICROFER 7216

Alloy Digest ◽  
1996 ◽  
Vol 45 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Iron Alloy ◽  
Heat Treating ◽  
Good Resistance ◽  
Nickel Chromium ◽  
Resistance To Oxidation ◽  
Resistance To Stress

Abstract Nicrofer 7216 is a nickel-chromium-iron alloy, with good resistance to oxidation, carburization, and nitriding; good resistance to stress-corrosion cracking; and good resistance to dry chlorine and hydrogen chloride. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-518. Producer or source: VDM Technologies Corporation.

NOM and MIB, who wins in the competition for activated carbon adsorption sites?

2004 ◽  
Vol 49 (9) ◽  
pp. 257-265 ◽  
Author(s):  
C. Hepplewhite ◽  
G. Newcombe ◽  
D.R.U. Knappe
Keyword(s):  
Molecular Weight ◽  
Activated Carbons ◽  
Background Concentration ◽  
Low Molecular Weight ◽  
Activated Carbon Adsorption ◽  
Microporous Carbons ◽  
Adsorption Sites ◽  
Carbon Adsorption ◽  
Competitive Mechanism ◽  
Wide Range

The adsorption of an odour compound common in drinking water, 2-methylisoborneol (MIB), was studied on two activated carbons in the presence of 13 well-characterised natural organic matter (NOM) solutions. It was found that, although the carbons and the NOM solutions had a wide range of characteristics, the major competitive mechanism was the same in all cases. The low molecular weight NOM compounds were the most competitive, participating in a direct competition with the MIB molecule for adsorption sites. Equivalent background concentration (EBC) calculations indicated a relatively low concentration of directly competing compounds in the NOM. Some evidence of pore restriction was also seen, with microporous carbons most affected by low molecular weight NOM, and mesoporous carbons impacted by the higher molecular weight compounds.

Effect of Block Molecular Weight on the Mechanical Properties of PA1010-b-PEG Segmented Block Copolymers

2012 ◽  
Vol 512-515 ◽  
pp. 2127-2130
Author(s):  
Li Huo ◽  
Cai Xia Dong
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Block Copolymers ◽  
Microphase Separation ◽  
Soft Segment ◽  
Mechanical Measurements ◽  
Wide Range ◽  
Hard Block ◽  
Higher Temperature ◽  
Hard Segments

The mechanical properties were investigated of a series of PA-PEG thermalplastic elastomer based on PA1010 and polytetramethylene glycol (PEG) with varying hard and soft segment content. Dynamic mechanical measurements of these polymers have carried out over a wide range of temperatures. The block copolymers exhibit three peaks, designated as α, β and γ in the tanδ-temperature curve. The α transition shifts to higher temperature with increasing hard block molecular weight. However, at a constant hard molecular weight, the α transition shifts to higher temperature and the damping increases on increasing the soft segment molecular weight. DMA results show that the block copolymers exhibit a microphase separation structure and both soft and hard segments were found to be crystallizable. The degree of phase separation increases with increasing hard block molecular weight.

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