Electrospinning of poly(lactic acid) stereocomplex nanofibers

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Stereocomplexation of poly(lactic acid) isomers is crucial for advanced material properties.
• High-molecular-weight poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA) present challenges in achieving pure stereocomplex structures.
• Electrospinning offers a versatile method for nanofiber fabrication.

Purpose of the Study:

• To investigate the electrospinning of high-molecular-weight PLLA/PDLA blends.
• To characterize the resulting stereocomplex nanofibers.
• To determine the effect of applied voltage on crystallite formation.

Main Methods:

• Electrospinning of PLLA/PDLA (1:1) blends using chloroform as a solvent.
• Varying applied voltages (-12 kV and -25 kV) to control nanofiber diameter.
• Wide-angle X-ray scattering (WAXS) analysis to assess crystallinity.

Main Results:

• Successfully produced stereocomplex nanofibers with diameters ranging from 400-1400 nm.
• Increasing voltage decreased homo-crystallite content (PLLA or PDLA) from 5% to 1%.
• Increasing voltage slightly increased stereocomplex crystallite content from 16% to 20%.

Conclusions:

• Electrospinning is effective for preparing stereocomplex nanofibers with minimal homo-crystallites, even from high-molecular-weight polymers.
• High voltage-induced orientation enhances stereocomplex crystallite formation and growth.
• Electrospinning suppresses homo-crystallite formation, yielding purer stereocomplex structures.