Title
Effect of different parameters on the fabrication of sustained release cellulose acetate and ethyl cellulose polymer blends
Authors
SYEDA UM-I-ZAHRA HEYU LI and LIMIN ZHU

Received July 7, 2015
Published Volume 51 Issue 9-10 September-December
Keywords electrospinning, polymer blends, cellulose acetate, ethyl cellulose

Abstract
In this paper, the effects of solvent system, applied voltage and ratio of polymers on the morphological appearance and diameters of nanofibers electrospun from cellulose acetate (CA) and ethyl cellulose (EC) polymer blends have been investigated. Single solvent systems, i.e. acetone, N,N-dimethyl acetamide (N,N-DMAc), N,N-dimethyl formamide (N,N-DMF) and acetic acid, and mixed solvent systems, i.e. acetone+N,N-DMAc, acetone+N,N-DMF, acetone+N,N DMAc+ethanol, were investigated. Electrospinning of polymer blends in acetone produced short and beaded nanofibers, while in N,N-DMAc, N,N-DMF and acetic acid, round, hollow and diffused microcapsules were produced, respectively. The effect of voltage on fiber morphology and diameter for solvent mixtures of acetone+N,N-DMAc and acetone+N,N DMF was also investigated. Moreover, the effect of polymer ratio on fiber morphology and diameter for the solvent mixture of acetone+N,N-DMAc+ethanol was studied. Bead-free nanofibers were observed as the concentration of CA increased and EC decreased in the polymer blend solution. After immersion in distilled water for 24 h, the electrospun CA+EC nanofibers swelled appreciably (i.e. from 702 to 1250%) with minor weight loss (1.6-1.2%). It was also found that the viscosities of the blend solutions decreased with an increase in the conductivity and voltage applied.