Study on extracting hemicellulose, cellulose, and carboxymethyl cellulose from Vietnamese rice straw waste
Keywords:carboxymethyl cellulose, cellulose, hemicellulose, Vietnamese rice straw waste
Cellulose and hemicellulose were successfully extracted from Vietnamese rice straw waste. The maximum hemicellulose yield of the process was 22.60% with 1.5 M NaOH at 90oC for 1.5 h. The pure cellulose obtained from the rice straw was prepared by refluxing the rice straw powder with a 1.0 M HNO3 solution at 90oC for 1.5 h. The Vietnamese rice straw cellulose was converted to carboxymethyl cellulose (CMC) by etherification. The extracted cellulose was soaked in a mixed solution of isopropyl alcohol and NaOH solution for 1.5 h. After that, it was reacted with monochloroacetic acid at 70oC for 1.5 h. The optimum conditions for carboxymethylation were 5 g cellulose, 4.0 g monochloroacetic acid, and 15 ml 25% w/v NaOH and the obtained product had a degree of substitution (DS) of 0.70.
Received 15 May 2020; accepted September 2020