Photochemical crack healing in cinnamate-based polymers.
Four kinds of cinnamate-type monomers were synthesized as healing agents. Photoirradiation of the monomers gave cyclobutane-containing crosslinked polymers via [2+2] cycloaddition. Cyclobutane cleavage upon cracking of the crosslinked polymers and re-cycloaddition of the cracked polymers were investigated by FT-IR spectroscopy. Photochemical crack healing was demonstrated by measurement of flexural strength of crosslinked, cracked, and healed polymers. It was observed that microcracks with width of 200 nm to 2 microm were healed by photoirradiation.
Department of Chemistry, Yonsei University, Wonju, Kangwon-do 220-710, Korea.
Sung-Youl
SY
Cho
Joong-Gon
JG
Kim
Chan-Moon
CM
Chung