Lignin as a UV Light Blocker-A Review.

Area of Science:

• Polymer Science
• Materials Science
• Photochemistry

Background:

• Lignin is a abundant natural phenolic biopolymer, a byproduct of pulp/paper and biorefining industries.
• It possesses chromophore functional groups, enabling broad-spectrum UV light absorption (250-400 nm).
• Lignin's potential as a UV-protective agent in sunscreens, films, paints, and varnishes is under investigation.

Purpose of the Study:

• To evaluate lignin's efficacy as a UV-blocking agent in commercial products.
• To explore synergistic effects of lignin with synthetic UV blockers.
• To identify challenges and areas for future research in utilizing lignin as a bio-based UV blocker.

Main Methods:

• Incorporation of lignin (non-modified and modified forms) into various product formulations.
• Assessment of UV protection enhancement in commercial products with low lignin blends (<10%).
• Evaluation of lignin's performance in mixtures with synthetic UV blockers.

Main Results:

• Lignin, even in small amounts, enhances UV protection in commercial products.
• Synergistic effects observed when lignin is combined with synthetic UV blockers, increasing overall UV blocking potential.
• Lignin demonstrated improved UV protection compared to using synthetic blockers or lignin alone.

Conclusions:

• Lignin shows significant promise as a natural, bio-based UV blocker for diverse applications.
• Its combination with synthetic blockers offers enhanced UV protection.
• Challenges such as complex structure, molecular weight variability, color, and impurities require further investigation for optimization.