Curable Compositions for Composite and Tool Release

A curable, two component, mold blocking material, including:

• a resin part comprising,
• a curable resin selected from multifunctional, hydroxyl di-terminated polymer having alkene segments and epoxide segments in the polymer chain;
• an epoxy di-terminated block copolymer having siloxane moieties and bisphenol A moieties in the backbone and combinations thereof;
• optionally a reactive diluent, a non-reactive diluent, a release agent, a filler, an additive or a combination thereof;
• a hardener part comprising,
• at least one curative;
• optionally a non-reactive diluent, a release agent, filler, an additive or a combination thereof;
• wherein cured reaction products of the mixed mold blocking material have an adhesion strength of less than or equal to 1,000 psi when tested using a lap shear test and the lap shear test sample exhibits at least some adhesive failure.