Process for preparing low density porous crosslinked polymeric materials
AssigneeShell Oil Company
InventorsRonald M. Bass, Thomas F. Brownscombe
Life of this patent
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Abstract
A process for the production of a stable curable water-in-oil high internal phase emulsion containing monomers as the continuous phase is provided by adding an initiator subsequent to formation of a water-in-oil high internal phase emulsion. The process forms uniform stable water-in-oil high internal phase emulsions in a continuous mixing process. These curable water-in-oil high internal phase emulsions are useful for the preparation of low density porous crosslinked polymeric materials.
Claims20
A process for the preparation of a porous crosslinked polymeric material comprising the steps of:
- (a) providing an aqueous stream comprising water and an electrolyte,
- (b) providing a monomer stream comprising a mixture of polymerizable monomers comprising at least one vinyl monomer and from about 2 to about 70 weight percent, based on the mixture, of a difunctional unsaturated crosslinking monomer,
- (c) providing a surfactant to the aqueous stream, the monomer stream, or both the aqueous and the monomer stream,
- (d) combining and mixing said aqueous stream and said monomer stream in a mixing vessel under conditions effective to produce a water-in-oil high internal phase emulsion having at least 90 weight percent, based on the emulsion, of water as the internal phase,
- (e) then adding to at least a portion of said water-in-oil high internal phase emulsion an effective amount of a polymerization catalyst to cure the polymerizable monomers thereby producing a curable water-in-oil high internal phase emulsion, and
- (f) then polymerizing the curable water-in-oil high internal phase emulsion at a temperature of at least about 25.degree. C. for a time effective to cure the monomers.
A process for the preparation of a porous crosslinked polymeric material comprising the steps of:
- (a) providing an aqueous stream comprising water and an electrolyte,
- (b) providing a monomer stream comprising a mixture of polymerizable monomers comprising at least one vinyl monomer and from about 2 to about 70 weight percent, based on the mixture, of a difunctional unsaturated crosslinking monomer,
- (c) providing a surfactant to the aqueous stream, the monomer stream, or both the aqueous and the monomer stream,
- (d) combining and mixing said aqueous stream and said monomer stream in a mixing vessel under conditions effective to produce a water-in-oil high internal phase emulsion having at least 90 weight percent, based on the emulsion, of water as the internal phase,
- (e) withdrawing at least a portion of said water-in-oil high internal phase emulsion from the mixing vessel,
- (f) then adding to the withdrawn water-in-oil high internal phase emulsion an effective amount of a polymerization catalyst to polymerize and cure the polymerizable monomers thereby producing a curable water-in-oil high internal phase emulsion, and
- (g) then polymerizing the curable water-in-oil high internal phase emulsion at a temperature of at least about 25.degree. C. for a time effective to cure the monomers.
Dependencies are inferred from the claim text.