Study on synthesis, rheological and electrospinning functional materials of carboxymethyl cellulose lithium (CMC-Li)

Abstract

The study on electrospinning of natural polysaccharide polymer to be nano-crystallized is still difficult in the current time. Carboxymethyl cellulose sodium (CMC-Na) was successfully synthesized and acidized to obtain carboxymethyl cellulose hydrogen (CMC-H), and new ionic cellulose ether CMC-Li was synthesized by alkalization, and then we analyzed the difference of structure between the three products. By comparing the rheological measurement and analysis of CMC-Na and CMC-Li, which have different mass fractions, it is found that they both show the characteristics of non-Newtonian fluid. The non-Newtonian index of CMC-Li is lower than that of CMC-Na when the degree of substitution (DS) and viscosity of both is similar. For the same material, the ionic cellulose ether solution of lower DS and higher concentration shows the lower non-Newtonian index. For the structure and property characteristic of polymers, it was easy to combine them with water-soluble hydroxyl terminated high molecular weight polyethylene oxide (PEO) to allocate the excellent electrospinning solution. Processing conditions were adjusted to a flow rate of 4 mL/h, an applied voltage of 25 kV, the spinning distance of 12 cm, the better appearance of nanofibers whose average diameter is about 70 nm can be obtained. In the process of electrospinning, hydroxyl lithium ester enolates was obtained by reductive reaction of the ionized Li+ with active hydroxyl, which caused the molecular structure to be destroyed. CMC-Li showed the exceptional Non-Newtonian fluid properties and had the better spinning performance than CMC-Na. When the surface tension of liquid was damaged by external electric force of spinning voltage to balance each other, the obtained morphology of the fiber was better. Nano-aluminum powder is coated with CMC-Li to form composite nanofibers, and carbonized at the high temperatures. Al/CNF/Li composite fiber was obtained in which nano particles were uniformly distributed. We preliminarily studied the obtained composite material that remained morphology and structure of fiber, which lays the foundation for the later research that the material is applied to soluble membrane, tissue engineering scaffolds, biological medicine, lithium battery and super capacitor, etc. The satisfactory effects have been achieved through analysis of IR, Rheology and SEM. The paper expands the type of polysaccharide polymer that can be electrospun and filled the void of related research, and it also lays the foundation for the study on nano functional materials of new ionic cellulose ether. © 2013 Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.