Improving anti-UV performances of cotton fabrics via graft modification using a reactive UV-absorber

In this study, a reactive UV-absorber (UV-DTHM) was synthesized by the reaction of 2,4-dihydroxy benzophenone with 2,4,6-trichlorotriazine and showed excellent ultraviolet absorption property and good thermostability. Using pad-dry-steam process, UV-DTHM was grafted into bleached cotton fabric through the covalent surface modification of the cotton fibers. The optimal finishing conditions, such as amount of the catalyst, temperature of the finishing bath, steaming time and concentration of UV-DTHM, were discussed. The UV-DTHM-modified cotton fabrics were characterized by FTIR spectroscopy, SEM and ultraviolet protection factor (UPF), etc. It was found that the highest value of UPF, 46.5, can be obtained in the conditions of 60 °C, 2 % owf UV-DTHM and dipping 60 min, and that UPF remained constant and was still more than 30 after thirty consecutive launderings, which showed strong anti-UV performance and fairly good durability.