Multi-functional microencapsulated additives for polymeric compositions
Multi-functional microcapsules comprising a core material including a major portion of one or more functional additives and a shell material including at least one functional additive, a method of manufacturing such multifunctional microcapsules and polymeric products incorporating such multifunctional microcapsules are provided.
1. A polymeric foam comprising:
a polymeric matrix; and
a plurality of multifunctional microcapsules distributed in the polymeric matrix, the microcapsules including a core material that provides a flame retarding function surrounded by a layer of a shell composition that provides at least one of fire retarding, flame suppressing, conductivity modifying, thermal stabilizing or insecticidal functions.
2. The polymeric foam according to claim 1 , wherein:
the core material includes a major portion of flame retardant; and
the shell material includes a major polymeric component and a minor functional additive component.
3. The polymeric foam according to claim 2 , wherein:
the polymeric matrix includes polystyrene; and
the microcapsules have a median diameter of less than 5 μm.
4. A polymeric foam according to claim 2 , wherein:
the major polymeric component includes at least one material selected from a group consisting of melamine formaldehyde, polyvinyl alcohol, polyester and polycarbonate; and
the minor functional additive component includes at least one material selected from a group consisting of fire retardants, flame suppressors, conductivity modifiers, thermal stabilizers and insecticides.
5. The polymeric foam according to claim 2 , wherein:
the flame retardant is selected from a group consisting of HBCD, DCP, BE-51, TPP and mixtures thereof; and
the major polymeric component is melamine formaldehyde and the minor functional additive component includes zinc borate.
6. The polymeric foam according to claim 2 , wherein:
the microcapsules account for between about 0.25 and about 10 weight percent of the polymeric foam; and
the microcapsules have a median diameter no larger than about 5 microns.
7. The polymeric foam according to claim 2 , wherein:
the flame retardant is selected from a group consisting of HBCD, DCP, BE-51, TPP and mixtures thereof; and
the major polymeric component is a polyurethane and the minor functional additive component includes zinc borate.