Multifunctional Cellulose Ester Containing Hindered Phenol Groups with Free-Radical-Scavenging and UV-Resistant Activities.

Excessive radicals and UV irradiation can trigger oxidative and physiological stresses, which cause tissue aging, human disease, food spoilage, and material degradation. In this study, a multifunctional cellulose ester containing hindered phenol groups, cellulose 3,5-di- tert-butyl-4-hydroxybenzoate (CBH), with free-radical-scavenging and UV-resistant activities was synthesized and used as a functional material. The obtained CBHs can effectively scavenge reactive nitrogen free radicals and hydroxyl free radicals in both solid and solution states. Moreover, CBHs have no cytotoxicity, and, on the contrary, they promote the proliferation of human epidermal keratinocytes. Benefiting from excellent solubility, processability, and formability, CBHs have been readily processed into flexible films, transparent coatings, and nanoribbons membranes. The highly transparent and flexible CBH film completely absorbs the light of 200-300 nm range and partially absorbs the light of 300-400 nm range, indicating a UV-shielding capability. After the CBHs were loaded on an ordinary facial mask by electrospinning or added into a hand cream, the resultant facial mask and hand cream exhibited outstanding free-radical-scavenging properties. In addition, CBHs can also be used to fabricate functional sprays with antioxidative and UV-shielding activities. Accordingly, the obtained CBHs have a huge potential in cosmetics, personal care products, biopharmaceuticals, papermaking, and art protection because of their excellent antioxidation, nontoxicity, UV resistance, formability, and odorless properties.