Surfactant-free filled polyurethane foam and method of making same
Polyurethane foams and methods of manufacturing are described herein. The foam can include (a) a polyurethane formed by the reaction of (i) one or more isocyanates selected from the group consisting of diisocyanates, polyisocyanates, and mixtures thereof, and (ii) one or more polyols; and (b) a filler. The amount of filler in the foam can be from 50 to 90% by weight, based on the total weight of the foam. The filler can include a plurality of fibers and/or a particulate filler. The polyurethane foams described herein are made without adding a surfactant to the reaction mixture. The density of the polyurethane foam can be at least 5 lb/ft 3 .
1. A filled polyurethane foam, comprising:
a polyurethane formed by (a) a reaction mixture comprising (i) one or more isocyanates selected from the group consisting of diisocyanates, polyisocyanates, and mixtures thereof, and (ii) one or more polyols; and (b) from greater than 50% to 90% by weight, based on a total weight of the polyurethane composite, of a filler;
wherein the filled polyurethane foam is made without adding a surfactant to the reaction mixture;
wherein the filled polyurethane foam has a density of at least 5 lb/ft 3 and a flexural strength from 100 psi to 700 psi; and
wherein the filler is a particulate filler having multimodal particle size distribution, the particle side distribution including a first mode with a median particle diameter of 2.0 microns or less and a second mode with a second median particle diameter of 3 microns to less than 40 microns.
2. The filled polyurethane foam of claim 1 , wherein the filled polyurethane foam further includes a plurality of fibers.
3. The filled polyurethane foam of claim 2 , wherein the plurality of fibers is present in an amount of from 0.25% to 10% by weight, based on the total weight of the filled polyurethane foam.
4. The filled polyurethane foam of claim 2 , wherein the plurality of fibers includes a plurality of glass fibers, polyalkylene fibers, polyester fibers, polyamide fibers, phenol-formaldehyde fibers, polyvinyl chloride fibers, polyacrylic fibers, acrylic polyester fibers, polyurethane fibers, polyacrylonitrile fibers, rayon fibers, cellulose fibers, carbon fibers, metal and metal-coated fibers, mineral fibers, or combinations thereof.
5. The filled polyurethane foam of claim 2 , wherein the plurality of fibers have an average aspect ratio of length to diameter of 8:1 to 700:1.
6. The filled polyurethane foam of claim 1 , wherein the particulate filler comprises fly ash.
7. The filled polyurethane foam of claim 1 , having a density of from 15 lb/ft 3 to 35 lb/ft 3 .
8. A method of making a filled polyurethane foam, comprising:
mixing one or more isocyanates selected from the group consisting of diisocyanates, polyisocyanates, and mixtures thereof, one or more polyols; and a particulate filler to produce a mixture, wherein the particulate filler is present in an amount from greater than 50% to 90% by weight, based on a total weight of the mixture, and wherein the mixture does not include a surfactant;
applying the mixture to a mold; and
allowing the mixture to react and expand to form the filled polyurethane foam, wherein the resulting filled polyurethane foam has a density of at least 5 lb/ft 3 ,
wherein the filled polyurethane foam has a flexural strength from 100 psi to 700 psi, and
wherein the particulate filler has a multimodal particle size distribution having at least two modes including a first mode with a first median particle diameter and a second mode with a second median particle diameter different than the first median particle diameter.
9. The method of claim 8 , wherein the mixture further includes a plurality of fibers.
10. The method of claim 9 , wherein the plurality of fibers is present in an amount of from 0.25% to 10% by weight, based on the total weight of the mixture.
11. The method of claim 9 , wherein the plurality of fibers have an average aspect ratio of length to diameter of 8:1 to 700:1.
12. The method of claim 9 , wherein the plurality of fibers includes a plurality of glass fibers, polyalkylene fibers, polyester fibers, polyamide fibers, phenol-formaldehyde fibers, polyvinyl chloride fibers, polyacrylic fibers, acrylic polyester fibers, polyurethane fibers, polyacrylonitrile fibers, rayon fibers, cellulose fibers, carbon fibers, metal and metal-coated fibers, mineral fibers, or combinations thereof.
13. The method of claim 8 , wherein the first median particle diameter or the second median particle diameter of the particulate filler is less than 50 microns.
14. The method of claim 8 , wherein the first median particle diameter or the second median particle diameter of the particulate filler is less than 25 microns.
15. The method of claim 8 , wherein the particulate filler comprises fly ash.