System for dimensionally stable isocyanate-free polyurethane foam

A polymeric foam free of isocvanate that is a reaction product of a polymer foam system free of isocvanate comprising a polyaldehyde, an inorganic powder, a polycarbamate, a blowing agent and an acid catalyst, wherein the polyaldehyde is in an A-side of the polymer foam system and the polycarbamate is in a B-side of the polymer foam system, the inorganic powder can be a separate component from the A- and B-sides or is in one or both of the A- and B-sides provided that the inorganic powder is not in the same side as the acid catalyst, the acid catalyst can be a separate component from the A- and B-side or is in the B-side and the blowing agent is in the A-side, the B-side, both the A- and B-sides or can be a separate component from the A- and B-sides, and further wherein:

• a. the inorganic powder is magnesium oxide, magnesium hydroxide, or calcium oxide, the inorganic powder having an average particle size of 3 to 25 μm;
• b. the polyaldehyde has an average functionality of more than one and less than three;
• c. the polycarbamate has an average functionality of 3.4 or more and 4.1 or less;
• d. the polycarbamate has an average equivalent weight of 250 grams per equivalent or more and 320 grams per equivalent or less;
• e. the average particle size of the inorganic powder in micrometers divided by the molar ratio of the inorganic powder to the acid catalyst is 2.5 or more and 9.3 or less;
• and
• f. the molar ratio of the polyaldehyde to the polycarbamate is 0.87 to 1.16 with the polycarbamate average equivalent weight being mass of the polycarbamate per carbamate group on said polycarbamate, average particle size of the inorganic powder determined by ASTM B822-10,
• wherein the polyurethane foam made by the polymer foam system has a density of 76-195 kilograms per cubic meter as determined by ASTM method D1622 and demonstrates 4-10% of volume change after exposure to an environment of 70 degrees Celsius and 97 percent relative humidity for 24 hours.