Polyurethane foams with agricultural by-products

A method of producing a polyurethane based foam, comprising:

• providing a ground crop residue including sunflower hulls having an average particle size of less than 10 mm and that is prepared by grinding crop residues including sunflower hulls;
• providing a polyurethane system that includes an isocyanate component and an isocyanate-reactive component, the polyurethane system having an isocyanate index from 70 to 350;
• forming a modified polyurethane system by adding the ground crop residue including sunflower hulls to the polyurethane system in a range from 1.0 wt% to 20.0 wt%, based on a total weight of the modified polyurethane system;
• and
• forming the polyurethane based foam so as to have an applied density from 30 kg/m3 to 75 kg/m3, according to ASTM D-1622, and to have the ground crop residue including sunflower hulls embedded within polyurethane polymers that are a reaction product of the isocyanate component and the isocyanate-reactive component of the polyurethane system.