Crystallization of Poly(L-/D-Lactide) in the Presence of Electric Fields

• Published in: Macromolecular chemistry and physics 2012-03, Vol.213 (6), p.635-642
• Main Authors: Yuryev, Yury, Wood-Adams, Paula M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Crystallization; electric field; Exact sciences and technology; nucleation; Organic polymers; Physicochemistry of polymers; polylactide; Properties and characterization; rheology
• ISSN: 1022-1352; 1521-3935
• DOI: 10.1002/macp.201100448

We report, for the first time, an enhancement in melt crystallization kinetics of poly(L‐/D‐lactide) (a type‐A1 polymer) in the presence of static electric fields as observed through measurement of the complex viscosity. Static electric fields of varying intensity (0–2.4 × 105 V m−1) are applied directly to the crystallizing polylactide melt at five different temperatures. The crystallization rate enhancement increases both with crystallization temperature and applied electric field intensity. An XRD analysis and optical microscopy studies allows us to attribute this to increased nucleation in the presence of an electric field. A technique allowing for the estimation of the rate of homogeneous nucleation induced by the electric field is developed. Enhanced crystallite nucleation in polylactide is observed under electric fields. This is caused by the permanent dipole parallel to the chain backbone in this type A1 polymer, which leads to chain orientation and stretch along equipotential lines. Understanding this phenomenon allows for improvements in electrospinning technology and more information about the physical processes associated with crystallization in polymers.