Process for the preparation of a polysulfide
View Patent ↗Pre-polymer according to structure (I) X—(R 2 —O) n —CH 2 —O—(R 1 —O) m —CH 2 —(O—R 2 ) p —X (I) wherein R 1 and R 2 can be the same or different and are selected from alkane chains containing 2-10 carbon atoms, X is a halogen atom, and n, m, and p are integers that can be the same of different and have a value in the range 1-6. The use of this pre-polymer in the preparation of a liquid polysulfide polymer allows better control over the sulfur and oxygen content and the polarity of the resulting polymer.
1. Process for the preparation of a polysulfide comprising the step of reacting a bis(2-dihaloalkyl)formal and a dihaloalkane with sodium polysulfide in the presence of
the pre-polymer according to structure (I)
X—(R 2 —O) n —CH 2 —O—(R 1 —O) m —CH 2 —(O—R 2 ) p —X (I)
wherein R 1 and R 2 can be the same or different and are selected from alkane chains containing 2-10 carbon atoms, X is a halogen atom, and n, m, and p are integers that can be the same or different and have a value in the range 1-6.
2. Process according to claim 1 wherein the bis(2-dihaloalkyl)formal is bis(2-dichloroalkyl)formal.
3. Process according to claim 1 wherein the dihaloalkane is an alpha-omega dihaloalkane.
4. Process according to claim 1 wherein the dihaloalkane is a dichloroalkane.
5. Process according to claim 1 wherein the dichloroalkane is selected from the group consisting of 1,2-dichloroethane, 1,2-dichloropropane, 1,3-dichloropropoane, 1,4-dichlorobutane, 1,5-dichloro pentane, 1,6-dichloro hexane, and isomers and combinations thereof.
6. Process according to claim 1 wherein the product resulting from the reaction of the bis(2-dihaloalkyl)formal, the dihaloalkane, and sodium polysulfide in the presence of the pre-polymer is treated with a reducing agent in order to obtain a liquid polysulfide.
7. Process for the preparation of a polysulfide comprising the step of reacting a bis(2-dihaloalkyl)formal and a dihaloalkane with sodium polysulfide in the presence of a pre-polymer obtained by a process wherein a polyol is reacted with (para)formaldehyde and a halo-alcohol in the presence of an acid catalyst.
8. Process according to claim 7 wherein the polyol is selected from the group consisting of monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, monopropyele glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, and mixtures thereof.
9. Process according to claim 7 wherein the halo-alcohol is a chloro-alcohol.
10. Process according to claim 9 wherein the chloro-alcohol is ethylene chlorohydrin.