Fabrication of Polylactide/Poly(epsilon-caprolactone) Blend Fibers by Electrospinning: Morphology and Orientation
writer：Lu, Liangliang，Wu, Defeng*，Zhang, Ming，Zhou, Weidong
keywords：none
source：期刊
specific source：Industrial & Engineering Chemistry Research
Issue time：2012年
Randomly oriented fiber mats and well-aligned fiber bundles of the biodegradable polylactide (PLA)/poly(ε-caprolactone) (PCL) blends were successfully produced by electrospinning in the present study. For the reticulate fibers, the effects of the blending ratio of two polymers and compositions of mixed solvents on fiber morphology were investigated. The results reveal that the fibers with lower PCL mass fraction show better morphology with larger average fiber diameter than those of the fibers with higher PCL mass fraction. Besides, a small addition of dimethylformamide (DMF) as the assistant solvent favors further improvement of fiber morphology because of the synergistic effects by improved conductivity and altered viscosity of the electrospun solutions. Although the as-obtained blend fibers show smooth surface structure, the phase separation between PCL and PLA occurs inside the fibers because the two components are thermodynamically immiscible, and the discrete phase shows an elongated morphology along with the fiber axis, instead of the droplet structure. For the aligned fiber bundles collected on a rotating disk, the degree of order increases with increase of the tangential velocity, accompanied by reduced average fiber diameter. Hierarchical orientations including the macroscopic fiber alignment, the elongation of discrete PCL phase, and the molecular orientation of both the PLA and PCL can be observed within the aligned blend fibers.