Using nitroxide decay to study the photooxidation kinetics of automotive topcoat enamels.
Free radical scavenging by nitroxide dopant is used to quantify the photoinitiation rate of free radicals in acrylic/melamine and polyester/urethane coatings during photolysis under "near ambient" exposure conditions. Photoinitiation rate measurements on weathered coatings reveal that acrylic/melamine coatings photooxidize non-autocatalytically, while polyester/urethane coatings photooxidize autocatalytically. The decomposition of hydroperoxide photolysis products by melamine crosslinker is claimed to account for this difference in photooxidation kinetics.
Gerlock
J L
JL
Ford Motor Company, Dearborn, MI 48121.
Bauer
D R
DR
Mielewski
D F
DF
D001336:Automobiles; D055598:Chemical Phenomena; D002621:Chemistry; D005609:Free Radicals; D009569:Nitric Oxide; D010084:Oxidation-Reduction; D010150:Paint; D010777:Photochemistry; D011108:Polymers / Q000032:analysis*
D005609:Free Radicals; D011108:Polymers; D009569:Nitric Oxide