title: Molecular weight kinetics and chain scission models for dextran polymers during ultrasonic degradation.
abstract: Ultrasonic degradation of six dextran samples with different initial molecular weights (IMW) has been performed to investigate the degradation behavior and chain scission mechanism of dextrans. The weight-average molecular weight (Mw) and polydispersity index (D value) were monitored by High Performance Gel Permeation Chromatography (HPGPC). Results showed that Mw and D value decreased with increasing ultrasonic time, resulting in a more homologous dextran solution with lower molecular weight. A significant degradation occurred in dextrans with higher IMW, particularly at the initial stage of the ultrasonic treatment. The Malhotra model was found to well describe the molecular weight kinetics for all dextran samples. Experimental data was fitted into two chain scission models to study dextran chain scission mechanism and the model performance was compared. Results indicated that the midpoint scission model agreed well with experimental results, with a linear regression factor of R2>0.99.
authors.affiliation: Center for Sugar Engineering and Technology Research, Guangxi University, Nanning 530004, PR China; College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, PR China. Electronic address: yuanyuan.pu@ucdconnect.ie.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Pu
authors.affiliation: Center for Sugar Engineering and Technology Research, Guangxi University, Nanning 530004, PR China; College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, PR China. Electronic address: Qingsong.Zou@ul.ie.
authors.forename: Qingsong
authors.initials: Q
authors.lastname: Zou
authors.affiliation: Center for Sugar Engineering and Technology Research, Guangxi University, Nanning 530004, PR China; College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, PR China. Electronic address: xiaozhihou90@126.com.
authors.forename: Dianzhi
authors.initials: D
authors.lastname: Hou
authors.affiliation: Center for Sugar Engineering and Technology Research, Guangxi University, Nanning 530004, PR China; College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, PR China. Electronic address: feyzhang1989@mail.scut.edu.cn.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Center for Sugar Engineering and Technology Research, Guangxi University, Nanning 530004, PR China. Electronic address: chenshan@gxu.edu.cn.
authors.forename: Shan
authors.initials: S
authors.lastname: Chen
keywords: Chain scission; Dextran; Kinetics; Molecular weight; Ultrasound