Non-isocyanate rigid polymer foams by carbon-Michael addition and foaming process

A process for making a polymer foam, comprising the steps of:

• forming an at least partially expanded reaction mixture by combining, at a temperature of at least 10° C., (1) a multifunctional Michael acceptor that has multiple Michael acceptor functionalities per molecule with (2) a multifunctional carbon-Michael donor in the presence of (3) a surfactant, (4) a carbon-Michael reaction catalyst and (5) a blowing agent composition containing a blowing agent that has a boiling temperature in the range −40° C. to +100° C.,
• dispensing the partially expanded reaction mixture and
• curing the dispensed reaction mixture to form a polymer foam,
• wherein the at least partially expanded reaction mixture is formed by:
• (a) forming a pressurized A-side component comprising the multifunctional Michael acceptor and, dissolved in the A-side component, a blowing agent composition containing a blowing agent that has a boiling temperature in the range −40° C. to +100° C.;
• wherein the A-side component has a Brookfield viscosity of 5,000 centipoises or less at 25° C.;
• (b) separately forming a pressurized B-side component comprising the multifunctional carbon-Michael donor, the surfactant and, dissolved in the B-side component, a blowing agent composition containing a blowing agent that has a boiling temperature in the range −40° C. to +100° C.;
• wherein the B-side component has a Brookfield viscosity at 25° C. from 0.2 to 5 times that of the A-side component but not greater than 2,500 centipoises;
• (c) separately depressurizing the pressurized A-side component and the pressurized B-side component such that the A-side component and the B-side component each at least partially expand due to expansion of the blowing agent composition;
• (d) combining the at least partially expanded A-side component and the at least partially expanded B-side component in the presence of the carbon-Michael reaction catalyst to form the reaction mixture.