Study about Photodegradation of Acrylic Resin Paint Films by ESR Spectrometer

Abstract

For the study of the photodegradation mechanism of acrylic paint films consisted of acrylate and methacrylate monomers, three kinds of acrylic resin have been synthesized from styrene, butyl acrylate, butyl methacrylate and hydroxyl methacrylate using three different kinds of initiator. The photodegradation process has been investigated by using ESR and FT-IR spectroscopies. It has been found from these results that in the initial photodegradation process of the paint film, -CH₂C (COOR) CH₂- radical is generated, which is followed by the formations of end-vinyl compound, tertiary alcohol and secondary amine.
Acrylic resins consisted of same monomers and having different OH-values and molecular weights have been synthesized. Using these resins, the relationships between the concentration of the generated radicals from the films and the periods at which cracking began to, appear in the clear paint films by QUV test were also examined.
As a result, the smaller the OH values and the larger the molecular wight, the generated radical concentration smaller and the cracking period longer.