An investigation into the polylactic acid texturization through thermomechanical processing and the improved d33 piezoelectric outcome of the fabricated scaffolds

Abstract

The bio/sensors performance has been established to be significantly affected through partially or entirely alignment of nano/microfibrous in polymeric mats. The matter of crystalline/amorphous proportion in semicrystalline polymers is another factor that can affect the application of the piezoelectric patches. The present work deals with fabricating the scaffolds of micro/nanofibers through a modified electrospinning procedure. The ratio of the relevant organic and polar solvents, the beading, the degree of fiber alignment, and fiber thickness have been intentionally elaborated. An unaligned unbeaded nanofibrous mat has been fabricated after tuning the solvents to poly-lactic acid ratio. This paper, for the first time, deals with the calculation of the value of d33 value of a commercial PLA and its improvement, it has been revealed that the d33 piezoelectric property is improved as a consequence of the thermo-mechanical processing above the cold crystallization temperature. The applied thermo (mechanical) processing causes the structural evolution from amorphous to crystallized states. Formation of the α and α′ crystalline phases is introduced as the main responsible for the improvement of the piezoelectric property. This improvement not only is correlated with the degree of crystallinity, but also the orientation and alignment of the crystallites is known to be influential. In this respect, the complex helical chain structural evolution of poly-lactic acid has been analyzed through Herman's orientation function. It has been found that, besides the characterized disorder-to-order phase transformation, the CO branched out dipoles interactions significantly affects by the texturization of the aligned polymeric chains in the direction of the electrospinning which is known as the main factor to promote the piezoelectric property of processed mat.

Keywords

• Piezoelectric
• Poly-lactic acid
• Thermomechanical processing
• Electrospinning
• Crystallinity
• Texturization