Location: Bioproduct Chemistry and Engineering Research
Title: Structural, electrical, mechanical, and thermal properties of electrospun poly(lactic acid)/polyaniline blend fibers
Submitted to: Macromolecular Materials and Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 15, 2010
Publication Date: July 12, 2010
Citation: Picciani, P.H., Medeiros, E.S., Pan, Z., Wood, D.F., Orts, W.J., Mattoso, L.H., Soares, B.G. 2010. Structural, electrical, mechanical, and thermal properties of electrospun poly(lactic acid)/polyaniline blend fibers. Macromolecular Materials and Engineering. 295: 618-627.
Interpretive Summary: Electrospinning is a simple and versatile technique that produces micro- and nano-structured polymer materials. Conductive electrospun nanofibers have multifunctional mechanical properties that allow their use in optics, electronics, biomedical devices, protective clothing, charge storage devices, sensors and actuators. Polyaniline is one of the most technologically promising precursors for electrospinning because of its chemistry, stability and low cost. Polylactic acid, a renewable, plant-derived resource, is a thermoplastic, biodegradable polymer that combines well with other materials to make composites. Casting or molding is an old technique used to make many types of materials. In this study, we develop composite materials made by electrospinning and by casting from blended polylactic acid and polyaniline. The electrospun materials were homogenous, without phase separation and had a single crystal type. The casted materials were heterogenous, exhibited phase separation and had at least two crystal types. Thus, properties of the electrospun material are more easily tailored to the end use of the material than casting. The electrical resistance of the electrospun material was two orders of magnitude higher than cast materials. The increased resistance suggests that electrospun materials would function well in electronic devices.
Conducting electrospun fiber mats based on PLA and PAni blends were obtained with average diameter values between 87 and 1,006 nm with PAni quantities from 0 to 5.6 wt.-%. Structural characteristics of fiber mats were compared to cast films with the same amount of PAni and studied by SEM, SAXS, and AFM. Thermal properties of fiber mats and cast films were compared by DSC analyses. Mechanical properties of fiber mats were also evaluated. It was found that electrospinning process governs the crystal structure of the fibers and strongly affects fiber properties. New properties of PLA/PAni blends are reported due to the size fiber reduction.