Characterize the molecular weight of cellulose with ionic liquids

Characterize the molecular weight of cellulose with ionic liquids

Cellulose , 1,4-β-glucan, is found in large quantities in the cell walls of various plants and is the most important skeletal component of plants. As an inexhaustible and inexhaustible biopolymer, cellulose has been considered a raw material with future development prospects and sustainability in the chemical industry. In addition, cellulose also has the advantages of extremely strong reversibility, complete biodegradability, excellent biocompatibility, high mechanical properties and structural designability.

Cellulose-based materials have been widely used in various fields of human society, such as textiles, food, medicine, papermaking, engineering materials, biofuels and composite materials. Since cellulose is a polydispersed polymer, the molecular weight and polydispersity index (PDI) of cellulose-based materials have a great impact on its mechanical properties, crystallization properties, rheology properties, etc. For example, the tensile strength of regenerated cellulose fibers is positively correlated with the molecular weight of cellulose. In addition, cellulose chains with high polymerization degree (DP) are more likely to form orientation structures during the stretching process, further improving the mechanical properties of cellulose fibers.

In addition, PDI also has a significant impact on the spinability and tensile properties of cellulose fibers. As shown in Figure 1c, cellulose solution obtained has good spinning properties using high molecular weight cellulose (DP > 2000) with a proportion of cellulose with an intermediate PDI of 3.4 as raw material. It has high mechanical properties.

Therefore, determining the molecular weight parameters of cellulose is crucial for the design and application of cellulose-based materials. Developing effective methods that accurately measure cellulose molecular weight parameters is not only an urgent need for cellulose structural characterization, but also the basis for understanding the relationship between cellulose-based materials' structure and performance.

Characterization of At present, a standardized scheme for determining the molecular weight of cellulose has not been formed. The emergence of cellulose fibers has brought opportunities to develop new cellulose characterization methods, such as new viscosity methods, direct GPC methods and derivatized GPC methods. Compared with the traditional CED method, the viscosity method using ILs as solvent has the advantages of fast dissolution speed, mild, small cellulose degradation, high stability, and transparent and colorless solution. The direct GPC method and the derivatized GPC method use il as the eluent or reaction medium, and have the characteristics of fast detection process, wide adaptability and easy operation. Therefore, ILs show great potential in cellulose molecular weight characterization technology and will surely promote the development of cellulose science.cellulose molecular weight parameters is the basis and necessary condition for the design and application of cellulose materials.