ma7b02004_si_001.pdf (745.17 kB)
Manipulation of Crystallization Sequence in PEO‑b‑PCL Films Using Solvent Interactions
journal contribution
posted on 2017-11-06, 14:24 authored by Natasha Brigham, Christopher Nardi, Allison Carandang, Kristi Allen, Ryan M. Van HornThe
physical structure of polymer films is important for understanding
the observed macroscopic properties. In crystalline–crystalline
block copolymers, the hierarchical nature of assembly is even more
influential. Controlling this assembly process is crucial for tailoring
film properties. In materials where crystallization of each block
occurs nearly simultaneously, the ability to manipulate crystallization
order is desirable. Poly(ethylene oxide)-b-poly(ε-caprolactone)
(PEO-b-PCL) films were monitored via ATR-FTIR to
determine the crystallization order during drying from varying solvents.
PCL crystallized first from most solvents except toluene and ethyl
acetate, where PEO nucleation occurred first. Moreover, after melting
the sample to remove solvent–polymer interaction effects, PCL
was first to crystallize from the melt, as has been previously reported.
Differences in the films’ morphologies based on crystallization
order were observed using polarized optical microscopy. These results
demonstrate that the order of crystallization and the assembly within
the film were controllable when casting symmetric diblock PEO-b-PCL films from different solvents.