Synthetic lignin-like and degradable nanocarriers. Issue 32 (6th August 2021)

• Record Type: Journal Article
• Authors: Beckers, Sebastian J.; Fischer, Jochen; Wurm, Frederik R.
• Is Part Of: Polymer chemistry. Volume 12:Issue 32(2021)
• Page Start: 4661
• Page End: 4667
• Publication Date: 2021-08-06
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/d1py00818h
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : Bio-based lignin-like building blocks were synthesized and transformed into polyurethane nanocarriers by interfacial polymerization in a miniemulsion. The nanocarriers were degradable by fungal enzymes and might be used for agrochemical delivery. Abstract : Lignin is a highly abundant biopolymer that is a by-product formed during paper manufacturing. Lignin is degraded by certain lignase-producing fungi and is relatively stable towards hydrolysis, which makes it an attractive material for diverse applications ranging from packaging to agrochemical delivery. However, a major challenge that hinders the large-scale use of lignin is its ill-defined chemical structure as a crosslinked copolymer with a variable comonomer composition, which results in strong batch-to-batch variations. To eradicate such a structural heterogeneity, herein, we synthesized two lignin-like monomers, comprising linkages found in native lignin, i.e., phenylcoumaran and β-O-4-aryl ether, and used them for the preparation of lignin-like nanocarriers by interfacial crosslinking in an inverse miniemulsion. The lignin-like monomers are accessible by a 2- or 4-step synthesis starting from bio-based compounds and can be prepared on a multigram scale. They carry hydroxyl groups, which reacted with toluene diisocyanate to produce lignin-like polyurethane nanocarriers with diameters between 200 and 400 nm. The nanocarriers might be used for the encapsulation of fungicides and for plant protection, as the lignin-like structure allowed the degradation by lignase-producing fungi, which are the cause of many plant diseases. Therefore, the dispersions might be of interest as a degradable drug delivery system, e.g. in advanced plant protection, or as synthetic alternatives to natural lignin.