Blocking/deblocking resin systems for use as a “co-cure-ply” in the fabrication of large-scale composite structure

A method for bonding composite substrates comprising:

• providing a first composite substrate and a second composite substrate wherein both the first composite substrate and the second composite substrate are uncured or partially cured and comprise one or more reinforcement fibers and a first curable resin;
• coupling a co-cure prepreg tape onto a faying surface of both the first and second composite substrates wherein the co-cure prepreg tape comprises a second curable resin having one or more chemically protected polymerizable functional groups;
• curing the first and second composite substrates to the co-cure prepreg tape at a first temperature to form a co-cure prepreg tape portion wherein the first and second composite substrates are fully cured and the co-cure prepreg tape is partially cured;
• coupling the co-cure prepreg tape portion of the first composite substrate to the co-cure prepreg tape portion of the second composite substrate;
• applying a second temperature to facilitate deprotection with water and a hydrolysis catalyst of the chemically protected polymerizable functional groups to give unprotected polymerizable functional groups and cure the co-cure prepreg tape portion of the first composite substrate to the co-cure prepreg tape portion of the second composite substrate to form a single covalently bonded composite structure.