Biopolymer-based nanocomposites: effect of lignin acetylation in cellulose triacetate films

Abstract

We have prepared all-biopolymer nanocomposite films using lignin as a filler and cellulose triacetate (CTA) as a polymer matrix, and characterized them by several analytical methods. Three types of lignin were tested: organosolv, hydrolytic and kraft, with or without acetylation. They were used in the form of nanoparticles incorporated at 1 wt% in CTA. Self-supported films were prepared by vapor-induced phase separation at controlled temperature (35-55 °C) and relative humidity (10-70%). The efficiency of acetylation of each type of lignin was studied and discussed, as well as its effects on film structure, homogeneity and mechanical properties. The obtained results are explained in terms of intermolecular filler-matrix interaction at the nanometer scale, for which the highest mechanical resistance was reached using hydrolytic lignin in the nanocomposite.

Evaluation of PLA–lignin bioplastics properties before and after accelerated weathering

“…Depending on the source and extraction method used, the physico-chemical characteristics are different and influence the properties of materials in which are embedded. The effective use of lignin in composites with various biopolymers like PHB [12,13], starch [14], cellulose [15], chitosan [16] has been also reported in literature. Sahoo increasing polymeric dimethylene diphenyl diisocyanate (PMDI) compatibilizer content from 1% to 2%, due to a possible plasticization of the composite materials.…”

Organosolv lignin as natural grafting additive to improve the water resistance of films using cellulose nanocrystals

“…These films are based on cellulose nanocrystals 3-20 nm in width and 100 nm-2 lm in length that depend on their biological origin and are composed of linear chains of high molecular weight cellobiose, which are stabilized with numerous hydrogen bonds to obtain a highly crystalline polymer [38,39]. However, few coatings or nanocomposite films based on industrial lignins (e.g., lignosulfates, kraft lignin and acetylated lignin) containing cellulose fibers, its commercial derivatives, or noncellulosic polysaccharides have been developed [40][41][42][43].…”

Effect of mechanical activation on structure changes and reactivity in further chemical modification of lignin

“…It was performed according to the method reported in references [25,26] with minor modification: lignin sample (10 g) was added in a 250 mL Erlenmeyer flask using 4-dimethyl amino pyridine (DMAP, 0.5 g) as catalyst and 20 mL of 1,4-dioxane as solvent. Acetic anhydride was added to the flask as esterifying agent with a weight ratio of 2:1 (acetic anhydride:lignin).…”