Xx. Huang et al., PHOTODEGRADATION AND THE LOSS OF STAIN RESISTANCE OF STAIN BLOCKER TREATED NYLON, Textile chemist and colorist, 25(11), 1993, pp. 29-33
Studies at TRI indicate that nylon 6 and nylon 66 carpet fibers treate
d with stain blocker lose a significant portion of their stain resista
nce after long exposure to UV light. It is believed that during photod
egradation the chemical structure of the stain blocker is altered, red
ucing hydrogen bonding between the stain blocker and the fiber.