Olefin metathesis applied to cellulose derivatives—Synthesis, analysis, and properties of new crosslinked cellulose plastic films

Abstract

New crosslinked cellulose‐based plastic films were synthesized with olefin metathesis as a crosslinking reaction. Microcrystalline cellulose was first dissolved in a lithium chloride/N,N‐dimethylacetamide solvent system and acylated by ω‐undecenoyl chloride under microwave irradiation with N,N‐dimethyl‐4‐aminopyridine as the catalyst. Cellulose unsaturated fatty acyl esters with a degree of substitution (DS) ranging from 1.4 to 2.0 were then crosslinked by olefin metathesis with a first generation Grubbs catalyst. Crosslinking ratios (T) ranging from 20 to 90% were obtained for low catalyst amounts (<1.2%), but gels appeared when T was too high. To avoid this gel formation, cellulose was acylated with a mixture of lauroyl and ω‐undecenoyl chlorides. This internal dilution allowed us to obtain films of every case and various T (varying from 10 to 80% for a catalyst amount below 3.5%). Plastics were characterized by Fourier transform infrared (FTIR) spectroscopy, and the fatty acid mixture resulting from the hydrolysis of cellulose esters were analyzed by gas chromatography (GC) and NMR spectroscopy. Mechanical properties showed that the elastic modulus and tensile failure stress was higher when the plastic films were crosslinked. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 407–418, 2005

Chemical modification of cellulose by acylation: Application to adsorption of methylene blue

“…The carbon rate of cellulose in solution seems identical whereas the hydrogen one is slightly reduced due to the rupture of intermolecular hydrogen bonds (Joly et al 2004) in cellulose. Raw cellulose is able to trap water molecules between its polymer chains and during dissolution this adsorbed water is released.…”

“Click” reactions in polysaccharide modification

“…One major barrier is the potential for homodimerization (via self-metathesis (SM)) of the CM partners, especially for type I olefins. In a typical example, Joly et al [183] observed SM of cellulose undec-10-enoate using Grubbs' catalyst (1 st generation, Figure 27), affording crosslinked and insoluble cellulose plastic films. For polymer modification targeting discrete and soluble products though, such crosslinking is not only undesired, but even disastrous.…”

“…The authors demonstrated that the CM reaction occurred selectively at the oil-water interface of the aqueous nanodroplets. This strategy of using olefin metathesis to prepare cross-linked polysaccharides is not new (as mentioned in previous paragraph, Joly et al prepared cross-linked cellulose plastic film by SM reaction[183]). However, the current research showed the adaptability of the CM reaction under emulsion conditions.…”

Synthesis of fructooligosaccharide-based plastic films starting from inulin

“…The degrees of substitution (DS = number of grafted chains per anhydrofructose unit; DS max = 3) were determined by 1 H NMR (using integration), and confirmed by FT-IR spectroscopy and volumetry [8].…”