Process for the preparation of a polysulfide
View Patent ↗Process for the preparation of polysulfide of formula (I) HS—(CH 2 ) n —O—(CH 2 ) m —O—(CH 2 ) p —[S—S—CH 2 ) n O—(CH 2 ) m —O—(CH2) p ] q —SH (I) wherein m is an integer in the range 1 to 4, n and p are integers in the range 1-10, and q is an integer in the range 1-60, by oxidizing a bismercaptodiether compound of formula (II) HS—(CH 2 ) n —O—(CH 2 ) m —O—(CH 2 ) p —SH (II) with elemental sulfur in the presence of a base and a protic solvent. This process has a high selectivity towards linear disulfides.
1. A process for the preparation of polysulfide of formula (I)
HS—(CH 2 ) n —O—(CH 2 ) m —O—(CH 2 ) p —[S—S—(CH 2 ) n —O—(CH 2 ) m —O—(CH 2 ) p ] q —SH (I)
wherein m is an integer in the range 1 to 4, n and p are integers in the range 1-10, and q is an integer in the range 1-60,
by oxidizing a bismercaptodiether compound of formula (II)
HS—(CH 2 ) n —O—(CH 2 ) m —O—(CH 2 ) p —SH (II)
with elemental sulfur in the presence of a base and a protic solvent.
2. The process according to claim 1 wherein m=1.
3. The process according to claim 1 wherein n=p=2.
4. The process according to claim 1 wherein the protic solvent is an alcohol.
5. The process according to claim 4 wherein the alcohol is methanol, ethanol or isopropanol.
6. The process according to claim 1 wherein the base is a quaternary ammonium compound, a tertiary amine, or an inorganic base.
7. The process according to claim 6 wherein the base is triethylamine or NaOH.
8. The process according to claim 1 wherein the molar ratio elemental sulfur:bismercaptoether is in the range 0.5:1 to 1.2:1.
9. The process according to claim 8 wherein the molar ratio elemental sulfur:bismercaptoether is in the range 0.7:1 to 0.99:1.
10. The process according to claim 1 wherein the process is performed at a temperature in the range 60-85° C.
11. A process for the preparation of a liquid polysulfide of formula (I)
HS—(CH 2 ) n —O—(CH 2 ) m —O—(CH 2 ) p —[S—S—(CH 2 ) n —O—(CH 2 ) m —O—(CH 2 ) p ] q —SH (I)
wherein m is an integer in the range 1 to 4, n and p are integers in the range 1-10, and q is an integer in the range 1-60,
by oxidizing a bismercaptodiether compound of formula (II)
HS—(CH 2 ) n —O—(CH 2 ) m —O—(CH 2 ) p —SH (II)
with elemental sulfur in the presence of a base and a protic solvent.