A Dyligomer is disclosed. The Dyligomer has the structure 1 where B is a chemical moiety formed by reactions involving the NCO groups of a diisocyanate the formulas OCNnullBnullNCO and the active hydrogens of OH groups of compounds having the formulas AnullOH and DnullOH, and A and D are chemical moieties formed by the reactions which formed B, and wherein A and D include, in their structures, at least two active hydrogens which are parts of OH groups and at least one ethylenic double bond. Also disclosed are polymerizable compositions comprising Dyligomers and their use to produce structural panels that are admirably suited for use as floors in refrigerated trucks and trailers, and in roofs, sidewalls and load bearing walls for homes and commercial buildings. Blocks which can be used to produce buildings are also disclosed, as is the use of Dyligomers to produce the blocks, and the use of the blocks to produce building structures.