scholarly journals Green chemistry and polymers made from sulfur

2017 ◽  
Vol 19 (12) ◽  
pp. 2748-2761 ◽  
Author(s):  
Max J. H. Worthington ◽  
Renata L. Kucera ◽  
Justin M. Chalker
Keyword(s):  
Green Chemistry ◽  
Elemental Sulfur ◽  
Polysulfide Polymers

Polysulfide polymers prepared from elemental sulfur have found increasing use in applications that benefit the environment.

Elemental Sulfur as a Plasticizer for Polysulfide Polymers and Other Polymers

1966 ◽  
Vol 39 (4) ◽  
pp. 1030-1040
Author(s):  
A. V. Tobolsky ◽  
N. Takahashi
Keyword(s):  
Mechanical Properties ◽  
Specific Volume ◽  
Elemental Sulfur ◽  
Preliminary Information ◽  
Quantitative Extraction ◽  
Metastable Condition ◽  
Molten Sulfur ◽  
Liquid Condition ◽  
Polysulfide Polymers ◽  
Elemental Form

Abstract So-called elastic sulfur obtained by quick-quenching molten sulfur from a temperature of 250° C to a temperature of about −10° C is really a mixture of polymeric sulfur and monomeric S8 sulfur, the latter in a metastable condition, Quick-quenched sulfur is elastic because of the plasticizing effect of the liquid S8 sulfur on the polymeric sulfur. In this publication we show that large concentrations of S8 can exist dissolved in a liquid condition in other polymers where it also acts as a plasticizer. In many cases these compositions appear completely stable, i.e., there is no tendency for the dissolved sulfur to crystallize out. The best example is crosslinked polyethylene tetrasulfide polymers. These polymers can retain 40 per cent of dissolved sulfur in the form of liquid S8 over indefinitely long periods of time. We prove that the sulfur is in its elemental form by quantitative extraction with CS2. The specific volume of the dissolved sulfur shows it is in a liquid condition. The mechanical properties of the sulfur plasticized crosslinked polymers are just what would be expected from this type of structure. Preliminary information concerning sulfur in other polymers is presented.

Scanning Electron Microscope Study of Bacteria on Mineral Surfaces

1976 ◽  
Vol 34 ◽  
pp. 130-131
Author(s):  
V.K. Berry
Keyword(s):  
Oxidation Reaction ◽  
Electron Microscope Study ◽  
Elemental Sulfur ◽  
Thiobacillus Ferrooxidans ◽  
Physical Contact ◽  
Metal Sulfides ◽  
Low Grade ◽  
Mineral Surfaces ◽  
Mineral Surface ◽  
Scanning Electron Microscope Study

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.

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