Urethane-Based Hybrid Foams

Urethane-Based Hybrid Foams. Hydroxyl-terminated ester oligomers or vinyl esters which have terminal vinyl groups and pendant hydroxyl groups can react simultaneously with isocyanate groups and vinyl monomers in the presence of catalysts to obtain crosslinked hybrid polymers. [Pg.86]

Unsaturated polyesters with terminal hydroxyl or carboxyl groups can also react at the same time with isocyanate groups and a vinyl monomer, such as styrene, to produce hybrid polymers. Two kinds of reactions, the NCO-OH addition reaction and radical polymerization by the vinyl groups, can occur. In parallel to the two reactions, interference between the two reactions also can occur. Detailed studies on the interference reactions were studied by Hsu et al. (190). [Pg.86]

Examples of formulations for preparing unsaturated polyesters are shown in Table 25. [Pg.86]

Some examples of hybrid-resin-formation reactions are shown below. [Pg.88]

Example (1) Unsaturated monoalcohol (acryloesterol) and styrene monomer are reacted with a polyisocyanate in the presence of a urethane catalyst and a radical polymerization catalyst to form hybrid resins (52). Styrene monomer acts as a crosslinker and at the same time, acts also as a reactive diluent. The trade name of a commercial product of such systems is Arimax (Ashland Chemical) (107). [Pg.88]