Ultrafine Friction Grinding of Lignin for Development of Starch Biocomposite Films

Abstract

The work demonstrates the utilization of fractionalized lignin from the black liquor of soda pulping for the development of starch-lignin biocomposites. The effect of ultrafine friction grinding on lignin particle size and properties of the biocomposites was investigated. Microscopic analysis and membrane filtration confirmed the reduction of lignin particle sizes down to micro and nanoparticles during the grinding process. Field Emission Scanning Electron Microscopy confirmed the compatibility between lignin particles and starch in the composites. The composite films were characterized for chemical structure, ultraviolet blocking, mechanical, and thermal properties. Additional grinding steps led to the reduction of large lignin particles and the produced particles were uniform. The formation of 7.7 to 11.3% lignin nanoparticles was confirmed in the two steps of membrane filtration. The highest tensile strain of the biocomposite films were 5.09 MPa, which displays a 40% improvement compared to starch films. Further, thermal stability of the composite films was better than that of starch films. The results from ultraviolet transmission showed that the composite films could act as an ultraviolet barrier in packaging applications.

Starch biocomposites preparation by incorporating organosolv lignins from potato crop residues

“…Additionally, a new peak at around 1523 cm -1 emerged in the biocomposite spectra, attributed to the C=C groups introduced by the added lignins [48]. The diffractogram of pure starch (Neat starch) unveils a semi-crystalline structure with peaks occurring at approximately 2θ = 14.7°, 17°, and 18.5°.…”

Low-Cost Alkaline Pretreatments and Ultrafine Grinding in Nanocellulose Crystal Extraction from Giant Swamp Taro (Crytosperma merkusii) Processing Waste

“…The ultrafine grinding of the pretreated pulp was done with a supermasscolloiderMKCA6-5J grinder (Masuko Sangyo Co., Ltd., Japan) at a speed of 1500 rpm and a temperature of 78-79 °C (measured from the feed cone). First, the pre-ground GST (100 g dry weight) was diluted to a consistency of 1.7% with distilled water and pH was adjusted to 7 [45]. The suspension, which was under continuous stirring with an overhead mixer, was circulated using a peristaltic tube pump (Watson-Marlow Fluid Technology Group, USA) through the silicon carbide stone grinder from the vessel submerged in a hot water bath.…”

Study on Experiment and Simulation of Shear Force on Membrane with Dynamic Cross-Flow for Lignin in Black Liquor

“…There are many approaches to obtaining lignin, and lignin with different structures and properties can be recovered by means of different separation methods. Compared with traditional chemical separation technologies, such as acid, alkali and ionic liquid treatments, membrane technology has the advantages of low energy consumption and high energy conversion efficiency without a phase change in the separation process [ 11 , 12 ]. It can operate at room temperature and is suitable for the separation of heat-sensitive materials.…”