Compatibility between Cellulose and Hydrophobic Polymer Provided by Microfibrillated Lignocellulose

Abstract

Microfibrillated lignocellulose (MFLC) was produced from wood subjected to partial lignin extraction using an ethanol/water mixture. After homogenization, the average fibril diameter of MFLC was in the same range as conventional microfibrillated cellulose (MFC). Although MFLC exhibited higher wettability with water compared to MFC, AFM adhesion force measurements revealed high variability in surface polarity of MFLC compared to MFC. Specifically, domains of higher polarity than in MFC but also domains of lower polarity than in MFC were observed in MFLC. This tendency towards amphiphilic behavior of MFLC was used to provide enhanced compatibility with polycaprolactone and polystyrene matrices. With both polymers, a significantly more homogeneous distribution of fibrils was achieved using MFLC compared to MFC. In line with better dispersion of the fibrils, significantly more efficient mechanical reinforcement of polymers was obtained using MFLC compared to MFC.

Reduced polarity and improved dispersion of microfibrillated cellulose in poly(lactic-acid) provided by residual lignin and hemicellulose

“…6) show evidence for precipitation of lignin in terms of the surface morphology of MFLC. While MFC fibrils appear smooth, MFLC is characterised by the occurrence of numerous fine granular structures along the fibril surface, which are presumably lignin residues [15].…”

“…It was observed that lignin-containing MFC (microfibrillated lignocellulose, MFLC) shows higher fineness of fibrils compared to MFC prepared from bleached pulp [13,14], presumably due to the radical scavenging property of lignin. Also, MFLC exhibited less hydrophilicity compared to MFC, and was well miscible with nonpolar solvents [14,15]. When compounded with hydrophobic polymeric matrices, MFLC showed better dispersion and improved reinforcement efficiency compared to MFC [14][15][16][17][18].…”

“…Also, MFLC exhibited less hydrophilicity compared to MFC, and was well miscible with nonpolar solvents [14,15]. When compounded with hydrophobic polymeric matrices, MFLC showed better dispersion and improved reinforcement efficiency compared to MFC [14][15][16][17][18].…”

Mechanical and Morphological Evaluation of the Reinforcement of Polycaprolactone With Different Cellulose Fibers

“…It is difficult to achieve proper dispersion of the cellulose fibers in the polymer matrix due to the hydrophilicity of fibers and hydrophobicity of polycaprolactone. [9] For improved dispersion, chemical treatments can be performed on the natural fiber surface to improve the adhesion within the polymer matrix. This enhancement in compatibility generates good interfacial interaction that allows the composite to reach maximum mechanical performance.…”

Fast microwave-assisted acidolysis: a new biorefinery approach for the zero-waste utilisation of lignocellulosic biomass to produce high quality lignin and fermentable saccharides

“…14,15,16 Microwave heating has a dramatic effect on the reaction kinetics 17 and reduces overall reaction times substantially. 18 Cellulose and hemicellulose are more polar than lignin, 19,20 therefore they receive more energy input on microwave irradiation. Based on this selective heating, a highly efficient separation could potentially be achieved through microwave treatment, with far shorter reaction times.…”