A kinetic study of ultrasonic degradation of carboxymethyl cellulose

Abstract

In this study, the effect of power of ultrasound, temperature, and concentration of carboxymethyl cellulose (CMC) solution on the rate of ultrasonic degradation were investigated, and a kinetic model based on viscometry data was used to calculate the rate constants in different conditions. To investigation of effect of ultrasonic power on the degradation of CMC, the power of ultrasound was increased and observed that the viscosity of the CMC solution was decreased with an increase in the power of ultrasound, but the extent of the degradation in a constant power was found to decrease with an increase in concentration or temperature. The ultrasonic degradation of CMC solutions was carried out at different temperatures to investigate the effect of the temperature on the rate of degradation. The calculated rate constants indicated that the degradation rate of the CMC solutions decreased as the temperature increased. The degraded CMCs were characterized by gel permeation chromatography, and average molecular weights of ultrasonicated CMCs were compared in different reaction conditions.

Influence of Different Degradation Techniques on the Molecular Weight Distribution of κ -Carrageenan

“…Although a number of different rate models have been proposed for the degradation of polymers [37,38]. Previous studies proved that with an increase in concentration, the rate constant, k, was decreased respectively [39,40]. These observations are explained in terms of viscosity changes for different polymer concentrations.…”

The Effect of Molecular Weight of Carboxymethyl Cellulose on the Dispersion of Silicon Suspensions Investigated by the Ultrasonic Degradation Method

“…Unlike ball milling methods that require prolonged mixing (several hours), the ultrasonic degradation method simply requires a few minutes to adjust the chain length of polymers, rendering experimental procedures more convenient 20,22,24) . Moreover, unlike planetary centrifugal mixing, chemical degradation, and thermal degradation, ultrasonic degradation can control the chain length of polymers without altering their primary structure [25][26][27][28][29][30][31] . These advantages have made the ultrasonic degradation method extensively used for adjusting the molecular weight of various polymers, including CMC.…”

Ultrasonic Degradation of Polystyrene for Tailoring Molecular Weight and Polydispersity of Polystyrene Fragments

“…The application of the listed tertiary recycling methods depends especially on the respective synthesis process of the polymer. Additional interesting chemical recycling methods are photodegradation [12,13], ultrasound degradation [14][15][16][17][18][19][20][21][22] as well as microwave degradation [23][24][25]. These methods are not directly linked to a specific polymer synthesis method.…”