Encapsulation of phase change materials
AssigneeUnion Carbide Corporation
InventorJames C. Hatfield
Life of this patent
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Abstract
Solid phase change materials, such as CARBOWAX.RTM. polyethylene glycol 8000, are encapsulated in a condensation polymeric shell to provide heat storage material for use in such things as solar heating devices. The phase change material is put into particulate form and then is coated with a reactive monomer, such as ethylene diamine. Then the monomer coated particulates of phase change material are reacted with prepolymers, such as isocyanate-terminated polybutadiene diol, to form elastomeric, condensation polymeric shells. The polymers have elastomeric (flexible) segments which are the prepolymeric portions. The encapsulated phase change material has little or no significant loss of its latent heat of fusion due to its encapsulation.
Claims27
Process for preparing encapsulated phase change material particles for reusable thermal energy storage, comprising:
- (a) forming particles of a solid phase change material selected from the group consisting of a crystalline polymer, naphthalene, salt hydrate and a crystalline paraffin;
- (b) contacting said solid phase change material particles with a first reactive monomer which is terminated with reactive groups and which is in a liquid state, said first reactive monomer not being reactive with said solid phase change material particles, said first reactive monomer forming a coating thereof on the surface of said solid phase change material particles;
- (c) contacting said coated phase change material particles with a second reactive monomer which is terminated with reactive groups and which is in a liquid state;
- and
- (d) condensation polymerizing said first reactive monomer and said second reactive monomer to form a continuous, elastomeric, condensation polymeric shell around said particles.
Encapsulated phase change material particles for reusable thermal energy storage, comprising:
- (a) particles of said phase change material selected from the group consisting of a crystalline polymer, naphthalene, salt hydrate and a crystalline paraffin;
- and
- (b) a continuous, elastomeric, condensation polymeric shell encapsulating said particles, said polymeric coating being formed from a first reactive monomer, and a second reactive monomer, said first reactive monomer having been coated on the surface of said particles (a) while said particles (a) were in a solid state.
Dependencies are inferred from the claim text.