A series of polyurethanes was synthesized in which hard segments were generated from the rigid 4,4-diphenylmethane diisocyanate (MDI) and the flexible 4,4-dibenzyl diisocyanate (DBDI), alone or as mixtures. Changes induced by varying the type and number of isocyanates were followed. Materials based on the single DBDI were observed to crystallize. Crystallinity was strongly reduced when DBDI was mixed with MDI. Improvement in elastomeric properties was obtained when both diisocyanates were included and reacted together in a random manner.
- Cristina Prisacariu
- Elena Scortanu
- Virgil Barboiu
