Epoxy based reinforcing patches having improved damping loss factor

A reinforcing sheet, comprising:

• at least one layer of a reinforcing material, wherein the reinforcing material comprises woven fiberglass, and wherein the woven fiberglass ranges in thickness from 0.75 mm to 2.50 mm;
• a thermosetting adhesive associated with at least a portion of the reinforcing material, wherein the thermosetting adhesive includes a curing agent, and an epoxy-modified dimerized fatty acid combined with an epoxy terminated polyurethane interpenetrating network;
• wherein the curing agent is represented by at least one of the following tautomeric chemical structures:
• wherein the epoxy-modified dimerized fatty acid is represented by the following chemical structure:
• wherein R1 comprises an alkyl, cycloalkyl, polycycloalkyl, heterocycloalkyl, aryl, alkaryl, aralkyl, alkoxy, alkanoyl, aroyl, alkenyl, alkynyl and/or cyano group containing 35 to 40 carbon atoms;
• and
• wherein the epoxy terminated polyurethane interpenetrating network is represented by the following chemical structure:
• wherein A1 is represented by the following chemical structure:
• wherein R1 comprises an alkyl, alkenyl, and/or alkynyl group containing 1 to 36 carbon atoms, an oligomer, and/or a urethane polymer;
• and wherein A2=A1.