ma8b01503_si_001.pdf (448.67 kB)
Crystallization and Segregation Behavior at the Submicrometer Scale of PCL/PEG Blends
journal contribution
posted on 2018-09-11, 18:50 authored by Phuong Nguyen Tri, Robert E. Prud’hommeThe
crystallization and segregation behavior of immiscible polycaprolactone/poly(ethylene
glycol) PCL/PEG (50/50) blends was investigated using mainly resonance-enhanced
atomic force microcopy coupled with infrared spectroscopy (AFM-IR)
which allows a spatial resolution of the order of 30–50 nm.
Chemical infrared images of the blends at different scales highlight
their island-like spherulitic structures. The nanoscale IR spectra
on both sides of the spherulitic interfaces are different. The polymer
segregation mechanism of the blend in the spherulitic structure is
also investigated in which PEG is rejected outside of PCL spherulites
at low crystallization temperature (30 °C) while it is rejected
in the form of small nodules with a dimension in the order of few
micrometers, inside of PCL spherulites at higher crystallization temperature
(40 °C) due to the presence of an upper critical solution temperature
(UCST).