Green route to modification of wood waste, cellulose and hemicellulose using reactive extrusion

• Published in: Carbohydrate polymers Vol. 136; pp. 1238 - 1250
• Main Authors: Vaidya, Alankar A., Gaugler, Marc, Smith, Dawn A.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 20-01-2016
• Subjects: Cellulose; Cellulose - chemistry; Cyclic anhydride; Dust; Esterification; Extrusion; Green Chemistry Technology - methods; Hemicellulose; Molecular Weight; Polysaccharides - chemistry; Reactive extrusion; Succinic Anhydrides - chemistry; Temperature; Waste Products; Wood - chemistry; Wood waste; Hemicellulose; REX; Cyclic anhydride; Reactive extrusion; Cellulose; Esterification; Wood waste; SA; DS; TGA; DDSA; SD; MA; FTIR; Extrusion; SEM; MI
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2015.10.033

•Green and scalable route to functionalise wood waste, cellulose and hemicellulose.•Reactivity of anhydrides different with different biomass.•The effect of catalyst is variable and depends on anhydride and biomass.•High thermal stability of functionalised wood waste or cellulose.•Functionalised wood and cellulose can be potential filler materials in composite.
A large volume of wood waste is produced in timber processing industry which traditionally used in low value applications. Here, value addition to the wood waste (Sander dust) and cellulose, hemicellulose isolated thereof by functionalisation using cyclic anhydrides in a solvent-free and green reactive extrusion process is reported. The effect of extrusion temperature, catalyst and different weight ratios of Sander dust (SD):succinic anhydride (SA) on the esterification reaction is evaluated. The esterified products were characterised by the acid value, degree of substitution (DS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), solid state 13C NMR and thermo-gravimetric analysis (TGA). Under optimum extrusion conditions, mixed esters are formed, with highest acid value obtained for succinylation of cellulose (0.122g/g at DS of 0.350) which is two times higher compared to succinylated SD (0.059g/g at a weight gain of 0.452) and hemicellulose (0.043g/g at DS of 0.290). The reactivity trend for individual anhydride was: (1) SA−Cellulose>SD>hemicellulose; (2) maleic anhydride (MA)−SD>hemicellulose>cellulose and (3) dodecenyl succinic anhydride (DDSA)−SD≈cellulose≫hemicellulose. The pendant free carboxyl groups generated through functionalisation of wood waste, cellulose and hemicellulose without the presence of polymeric carriers will allow more tailored or targeted modification of wood-plastic composites.