METHODS FOR DESIGNING POLYISOCYANURATE FOAM-FORMING COMPOSITIONS, RELATED POLYISOCYANURATE FOAM-FORMING COMPOSITIONS, AND FOAMS PRODUCED THEREBY

Disclosed are methods for designing a polyisocyanurate foam-forming composition with good low temperature insulation performance. The methods include: (a) measuring the LTTR of a first polyisocyanurate faced foam laminate prepared from a first polyisocyanurate foam-forming composition comprising a blowing agent composition comprising one or more hydrocarbon blowing agents with an atmospheric pressure boiling point of at least 68° F. (20° C.), wherein the LTTR is measured according to CAN/UL S770-09 at a plurality of temperatures to identify a calculated inflection point temperature below which defines a first mathematical correlation between temperature and the LTTR of the first polyisocyanurate faced foam laminate and above which defines a second mathematical correlation between temperature and the LTTR of the first polyisocyanurate faced foam laminate; (b) identifying a plurality of predicted mathematical correlations between temperature and the LTTR of the first polyisocyanurate faced foam laminate at a plurality of reduced inflection point temperatures below the calculated inflection point temperature; and (c) using the plurality of predicted mathematical correlations identified in step (b) to design a second polyisocyanurate foam-forming composition that is different from the first polyisocyanurate foam-forming composition and which comprises a blowing agent composition comprising one or more hydrocarbon blowing agents with an atmospheric pressure boiling point of at least 68° F. (20° C.), wherein the second polyisocyanurate foam-forming composition produces a second polyisocyanurate faced foam laminate that has a LTTR of at least 5.4 ft2·hr·° F./BTU·inch (0.936 m2·° C./W@25 mm) at all mean insulation temperatures within a temperature range of 10° F. to 75° F. (−12.2° C. to 23.9° C.), when measured according to CAN/UL S770-09.