Ultrasonic mediated production of carboxymethyl cellulose: Optimization of conditions using response surface methodology

In the present research the optimization of ultrasound-mediated production of carboxymethyl cellulose under microwave irradiation, towards achieving reduction of chemicals, time of reaction and energy was carried out. Cellulose was extracted and treated by environmentally friendly chlorine free bleaching method using hydrogen peroxide. Produced alpha-cellulose was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric/differential thermal analysis (TG/DTA). Response Surface Methodology (RSM) was used to optimize the preparation of carboxymethyl cellulose (CMC). Highest degree of substitution 0.74 was obtained at 240 W ultrasonic power for 37 min followed by etherification at 490W microwave power for 12 min. Results show that the preparation of CMC from cotton linter using ultrasound and microwave energy can reduce the processing time, chemicals and energy consumption. Additionally, X-ray analysis shows that the ultrasonic energy is able to break cellulose crystals into smaller parts compared to other methods. SEM photographs showed that this treatment is able to remove impurities from raw material.