Method for the manufacture of polymeric sulfur
The present invention relates to a method for the manufacture of polymeric sulfur. The method includes reacting a metallasulfur derivative with an oxidizing agent to form polymeric sulfur.
1. A method for the manufacture of polymeric sulfur, comprising reacting a metallasulfur derivative with an oxidizing agent in a reaction zone to form polymeric sulfur in a polymeric sulfur-containing reaction mixture.
2. The method of claim 1 , wherein the metallasulfur derivative is characterized by the formula;
wherein
L is a monodentate or polydentate ligand species which may be the same or different when x>1;
x is the total number of ligand species and is from 0 to 6 inclusive;
M is a metal atom;
y is the total number of metal atoms and is from 1 to 4 inclusive;
S is a sulfur atom;
z is the number of sulfur atoms, and is from 1 to 12 inclusive;
u represents the charge of the metallasulfur derivative and may be from −6 to +6 inclusive;
v is the number of metallasulfur derivative units in an oligomeric or polymeric structure;
I is an ionic atom or group and may be cationic or anionic;
and w is the number of cationic or anionic atoms or groups, as required to provide charge neutrality.
3. The method of claim 2 , wherein the oxidizing agent is characterized by the formula:
X—X′
wherein X and X′ are the same or different and are selected from the group consisting of halogens and pseudohalogens.
4. The method of claim 3 , wherein the stoichiometric ratio of the oxidizing agent to the metallasulfur derivative is selected so that less than one equivalent of the oxidizing agent is present for every two M-S bonds in the metallasulfur derivative.
5. The method of claim 3 , wherein X and X′ are chlorine or bromine.
6. The method claim 1 , wherein the reacting is carried out at a temperature greater than ambient temperature.
7. The method claim 1 , wherein the reacting is carried out at a temperature from about 40° C. to about 60° C.
8. The method of claim 1 , further comprising reacting elemental sulfur with a sulfur templating agent to form the metallasulfur derivative prior to the step of reacting the metallasulfur derivative with the oxidizing agent.
9. The method of claim 1 , further comprising isolating the polymer from the polymer-containing reaction mixture by:
(i) dissolving impurities from the polymer-containing mixture by treating the polymer-containing mixture with a solvent for the impurities to form a dissolution liquor, followed by separating polymer particles from the dissolution liquor to obtain mother-liquor-wet polymer particles; and
(ii) drying the mother-liquor-wet polymer particles from step (i) to produce purified polymer.
10. The method of claim 1 , further comprising isolating the polymer from the polymer-containing reaction mixture by:
(i) contacting the polymer-containing mixture with a sedimentation solvent to produce a suspended slurry mixture and a settled particle layer;
(ii) dissolving impurities from the settled particle layer by treating the settled particle layer with a solvent for the impurities to form a dissolution liquor, followed by separating polymer particles from the dissolution liquor to obtain mother-liquor-wet particles; and
(iii) drying the mother-liquor-wet polymer particles to produce purified polymer.
11. The method of claim 1 , further comprising isolating the polymer from the polymer-containing reaction mixture by:
(i) dissolving impurities from the polymer-containing mixture by treating the polymer-containing mixture with a solvent for the impurities to form a dissolution liquor, followed by separating polymer particles from the dissolution liquor;
(ii) contacting the polymer particles with a sedimentation solvent to produce a suspended slurry mixture and a settled particle layer; and
(iii) separating the settled particle layer from the suspended slurry mixture to obtain purified polymer.
12. The method of claim 8 , further comprising forming a slurry of the sulfur templating agent in a solvent prior to the reacting step.
13. The method of claim 8 , further comprising forming a solution of the sulfur templating agent in a solvent prior to the reacting step.
14. A method for the manufacture of a polymeric sulfur compound, the method comprising:
(i) reacting cyclooctasulfur, tetramethylethylenediamine, and zinc in the presence of water to form a tetramethylethylenediamine/Zn(S 6 ) complex; and
(ii) reacting the complex with an oxidizing agent in the presence of a solvent for the complex at a temperature greater than ambient temperature.