Abstract:
This project reviews the degradation of polychloroprene based adhesives. The
first step in the oxidative degradation is the allylic hydrogen abstraction
leading to different radicals. Some hydroperoxides are formed and then
decomposed into alcohol, ketones, acid chlorides and acids. Acid value and
tintometer colour measurements are used to identify the amount of acid
released and hence the extent of degradation. The influence of phenolic
antioxidants on the oxidative degradation is studied.
Phasing occur in a polychloroprene based adhesive when the metal oxide and
the resin particles are not fully reacted. Eventually these unreacted particles
settle down at the bottom of the container. Among other factors the polarity of
the solvent system solvent strength, material type the shape and the size of the
resin and metal oxides are also important. A physical method to minimize phasing is studied.
