Abstract: A method for adhesively bonding two substrates, including the steps: (a) applying a liquid, radiation-curable primer composition onto the surface of a first substrate; (b) curing the liquid, radiation-curable primer composition by applying radiation with a suitable wavelength, intensity and temporal exposure such that the radiation-curable primer composition is cured into a solidified, coherent or interrupted layer adhering to the surface of the substrate; (c) optionally storing the primed substrate for a time of up to 6 months; (d) applying a curable adhesive composition onto the cured primer composition on the substrate; (e) joining a second substrate to the adhesive composition on the first substrate such that an adhesive bond is formed between the substrates, wherein the surface of the second substrate to be adhesively bonded is optionally pre-treated to improve adhesion before step (e) is performed; (f) curing the curable adhesive composition.

Abstract: A thermally expandable composition which includes at least one thermoplastic polymer, at least one chemical blowing agent, at least one free radical initiator, and at least one co-agent having at least two maleimide groups. The invention is also related to a baffle and/or a reinforcement element for hollow structures including the thermally expandable composition, to a process for manufacturing the baffle and/or the reinforcement element, to use of the baffle and/or the reinforcement element for sealing, baffling, or reinforcing of a cavity or a hollow structure, and to a method for sealing, baffling and/or reinforcing a cavity or hollow structure.