Polyisocyanurate/polyurethane elastomers based on suspensions of crystalline polyesters and polyhydroxyl compounds

A crystallite suspension comprising:

• (a) as the dispersed phase, from 3 to 70 weight percent of a crystalline, ethylenically unsaturated polyester prepared through the condensation polymerization of fumaric acid and ethylene glycol in a molar ratio of from 1:1.2 to 1:2 wherein up to 18 mole percent of the fumaric acid may be replaced by other aliphatic, cycloaliphatic, and/or aromatic carboxylic acids and up to 20 mole percent of the ethylene glycol may be replaced by other mono-, di-, or trifunctional alcohols, said crystalline, ethylenically unsaturated polyester having a molecular weight factor per double bond of about 154 to 408;
• and
• (b) as the coherent phase, from 30 to 97 weight percent of a polyhydroxyl compound having a functionality of from 2 to about 8, a hydroxyl number of from 20 to 800, and a melting point of less than 30.degree. C., wherein said weight percents are based on the total weight of components (a) and (b).