Biodegradable polyurethane foam slabstock and method of production

1 . A biodegradable polyurethane foam, comprising:

a polyol;

an isocyanate;

a blowing agent either equal to or no more than 4% of the biodegradable polyurethane foam by weight;

a catalyst either equal to or no more than 1% of the biodegradable polyurethane foam by weight;

a surfactant either equal to or no more than 1% of the biodegradable polyurethane foam by weight; and

a hydrophilic biodegradable solid additive either equal to or no greater than 3% of the biodegradable polyurethane foam by weight;

wherein the hydrophilic biodegradable solid additive includes polyethylene glycol-polycaprolactone copolymers;

wherein the biodegradable polyurethane foam using the hydrophilic biodegradable solid additive has a same performance characteristic profile as a polyurethane foam of a same composition but made without the hydrophilic biodegradable solid additive;

wherein the performance characteristic profile of the biodegradable polyurethane foam compared to that of the polyurethane foam made without the hydrophilic biodegradable solid additive includes measurements of density, texture, durability, and support factor;

wherein the hydrophilic biodegradable solid additive is non-starch based;

wherein the hydrophilic biodegradable solid additive has a particle size greater than or equal to 200 microns and less than 400 microns;

wherein the hydrophilic biodegradable solid additive is activated only when the biodegradable polyurethane foam is buried in a landfill; and

wherein the biodegradable polyurethane foam is at least 70% degraded into inert humus, methane and carbon dioxide within the landfill after 900 days.

2 . The biodegradable polyurethane foam in claim 1 , wherein the biodegradable polyurethane foam is either a biodegradable polyester foam or a biodegradable polyether foam.

3 . The biodegradable polyurethane foam in claim 1 , wherein the biodegradable polyurethane foam is either a biodegradable viscoelastic foam, a biodegradable open cell foam, or a biodegradable closed cell foam.

4 . The biodegradable polyurethane foam in claim 1 , wherein the polyol is between 58-64% of the biodegradable polyurethane foam by weight.

5 . The biodegradable polyurethane foam in claim 1 , wherein the isocyanate is between 20-45% of the biodegradable polyurethane foam by weight.

6 . A method of making the biodegradable polyurethane foam in claim 1 as a slab stock using a continuous pour method, comprising the steps of:

measuring the polyol, the isocyanate, the blowing agent, the catalyst, the surfactant, and the hydrophilic biodegradable solid additive;

mechanically mixing the polyol, the isocyanate, the blowing agent, the catalyst, the surfactant, and the hydrophilic biodegradable solid additive in a container to form a mixture;

pouring the mixture onto a conveyor belt at a controlled rate to form a bun; and

curing the bun on the conveyor belt.

7 . The method in claim 6 , wherein the biodegradable solid additive is either in a powdered or a pelletized form.

8 . The method in claim 6 , wherein the hydrophilic biodegradable solid additive is in a powdered or pelletized form with a particle size of 300 microns.

9 . The method in claim 6 , further comprising the steps of:

cutting the cured bun; and

removing the cut and cured bun pieces from the conveyor belt,

after the step of curing.

10 . The method in claim 6 , wherein the hydrophilic biodegradable solid additive consists of polyethylene glycol-polycaprolactone copolymers.

11 . The method in claim 6 , wherein the blowing agent comprises carbon dioxide.

12 . The method in claim 6 , wherein the blowing agent comprises water.

13 . The method in claim 6 , wherein the polyol is present in an amount of 58-64% by weight of the polyurethane foam.