题目：Preventing Films from Marking Powder Coated Surfaces 内容：
Preventing Films from Marking Powder Coated Surfaces

Lignin is a natural broad-spectrum sun blocker due to its UV-absorbing functional groups, e.g., phenol units. UV absorbers can protect materials such as paints and plastic from sun damage.

Richard Venditti, North Carolina State University, Raleigh, USA, and colleagues have developed sustainable, biodegradable, and transparent cellulose-lignin films that absorb UV radiation. The team functionalized cellulose with azide groups and lignin with propargyl groups and used a copper-catalyzed click reaction to form covalent bonds between them. They added between 0.5 wt% and 2 wt% lignin to the cellulose. The team cast the solution of t