Cellulose Nanocrystal Isolation from Hardwood Pulp using Various Hydrolysis Conditions

Abstract

To expand the application field of the pulping industry, this study conducted a series of sample preparations for processing cellulose nanocrystals (CNCs) from a dry hardwood pulp to achieve optimal sulfuric acid hydrolysis. The properties of laboratory-prepared pulp CNCs (P-CNCs) were investigated with different preparation conditions including sulfuric acid concentrations, hydrolysis temperatures, and hydrolysis durations. Results showed a gradient of color changes observed with the increase of hydrolysis duration and temperature. Under certain conditions, the derived P-CNCs exhibited nanoscale dimensions, detected by transmission electron microscopy, and a crystallinity index similar to commercial products. In addition, the surface sulfate groups were assumed to be contributed by sulfuric acid hydrolysis. However, a high acid concentration and long hydrolysis processing duration introduced more sulfate groups on the derived P-CNCs, which may have acted as flame retardants and, thus, increased the amount of char residue.

Relationship between Structural Characteristics of Cellulose Nanocrystals Obtained from Kraft Pulp

“…In all the CNC samples, two stages of CNCs degradation are observed. Similar antecedents have been reported by Kargarzadeh et al [ 21 ] and Lin et al [ 49 ]. The first stage presents a maximum peak of degradation temperature around 230 °C, and the second stage presents a maximum peak of degradation temperature above 350 °C ( Figure 5 b).…”

Fabrication and Properties of Tree-Branched Cellulose Nanofibers (CNFs) via Acid Hydrolysis Assisted with Pre-Disintegration Treatment

“…Such a phenomenon is attributed to two-step degradation of nanocellulose with sulfate groups existing at the end of crystalline cellulose and sulfated amorphous cellulose [46]. A short and stable stage is identified with respect to the degradation process of all nanocelluloses just prior to the further degradation between 290 • C and 500 • C where maximum decomposition temperature occurs at approximately 385 • C in Table 1 owing to the evident degradation of unsulfated interior crystalline phase [47]. Finally, the degradation continues to increase up to 800 • C in a relatively slow pace.…”

Thermal Behavior of Green Cellulose-Filled Thermoplastic Elastomer Polymer Blends

“…Therefore, the development of a new generation of eco-friendly materials representing a less environment-harmful alternative to commonly used plastics is highly desired [5]. As a consequence, more and more natural additives are being introduced to the polymer processing processes, e.g., various wood components [6][7][8][9][10], natural anti-aging agents [11][12][13], mineral fillers [14][15][16], starch-based materials [17,18].…”