Current advancement on the isolation, characterization and application of lignin.

Lignin is the by-product of pulp and paper industries and bio-refining operations. It is available as the leading natural phenolic biopolymer in the market. It has chromophore functional groups and can absorb a broad spectrum of UV light in range of 250-400 nm. Using lignin as a natural ingredient in sunscreen cream, transparent film, paints, varnishes and microorganism protection has been actively investigated. Both in non-modified and modified forms, lignin provides enhancing UV protection of commercial products with less than a 10% blend with other material. In mixtures with other synthetic UV blockers, lignin indicated synergic effects and increased final UV blocking potential in compare with using only synthetic UV blocker or lignin. However, using lignin as a UV blocker is also challenging due to its complex structure, polydispersity in molecular weight, brownish color and some impurities that require more research in order to make it an ideal bio-based UV blocker.

Lignin as a UV Light Blocker-A Review.

Review on tannins: Extraction processes, applications and possibilities

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A review on the fused deposition modeling (FDM) 3D printing: Filament processing, materials, and printing parameters

A High-Performances Flexible Temperature Sensor Composed of Polyethyleneimine/Reduced Graphene Oxide Bilayer for Real-Time Monitoring

We propose a new idea for facile and green synthesis of urea-based highly branched polymers (HBPs) using polyamines and urea via deamination. More importantly, our strategy is to directly use the s...

Novel Highly Branched Polymer Wood Adhesive Resin

The structural changes during three-step synthesis of low-molar ratio urea⁻formaldehyde (UF) resin were tracked by quantitative 13C nuclear magnetic resonance (13C NMR) analysis and electrospray ionization-mass spectrometry (ESI⁻MS). Condensations that produced polymers were found to be linked by ether bonds in addition to hydroxymethylation reactions at the first alkaline stage with a formaldehyde to urea ratio of 2:1. Considerable formation of branched methylene linkages, with the highest content among all the condensed structures, was the key feature of the acidic stage. Notable changes were observed for the chemical structures and molecular masses of the resin components after the formaldehyde to urea molar ratio was lowered to 1.2 by adding post-urea at the final alkaline stage. Specifically, most of the branched hydroxymethyl groups on the polymers were cleaved, resulting in a significant decrease in the branching degree of the polymers. The performance degradation of the UF resin was attributed to this debranching effect and the production of components with low molecular masses. Based on the observations, the curing pattern of low molar ratio UF resin was postulated and branched polymeric formaldehyde catcher bearing urea-reactivity was proposed.

Characterization of the Low Molar Ratio Urea–Formaldehyde Resin with 13C NMR and ESI–MS: Negative Effects of the Post-Added Urea on the Urea–Formaldehyde Polymers

Using, urea, one of the cheapest chemicals and convenient deamination polycondensation (solvent-free, catalyst-free, one-pot, one-step) provides an industrially relevant and environmentally benign ...

Superstrong Adhesive of Isocyanate-Free Polyurea with a Branched Structure

Tannin-furanic resin foam reinforced with cellulose nanofibers (CNF)

https://hal.univ-lorraine.fr/hal-02508080/document

Xiaojian Zhou

Papers

Novel Highly Branched Polymer Wood Adhesive Resin

Characterization of the Low Molar Ratio Urea–Formaldehyde Resin with 13C NMR and ESI–MS: Negative Effects of the Post-Added Urea on the Urea–Formaldehyde Polymers

Superstrong Adhesive of Isocyanate-Free Polyurea with a Branched Structure

Tannin-furanic resin foam reinforced with cellulose nanofibers (CNF)

Characterization and 3D printability of poly (lactic acid)/acetylated tannin composites