ma8b02265_si_001.pdf (2.13 MB)
Configurationally Constrained Crystallization of Brush Polymers with Poly(ethylene oxide) Side Chains
journal contribution
posted on 2019-01-10, 21:20 authored by Huilou Sun, Duk Man Yu, Shaowei Shi, Qingqing Yuan, So Fujinami, Xiaoli Sun, Dong Wang, Thomas P. RussellThe
influence of physical confinement on the crystallization of
poly(ethylene oxide) (PEO) has received much attention in past years.
Here, rather than constraining the crystallization of the polymer
by a physical or geometric boundaries, the influence of the constraints
imposed by the chain architecture on the crystallization of the PEO
was investigated, where the PEO chains were anchored to a poly(norbornene)
(PNB) backbone. In this brush or comb-type polymer, the crystallizable
polymer PEO are side chains comprising the bristles of the brush while
the PNB comprises the spine. The brush or comb-type polymers were
synthesized by the ring-opening metathesis polymerization (ROMP) of
a NB-modified macromonomer. Here, the crystallizable PEO is anchored
to the PNB backbone, placing constraints on the PEO during crystallization
and annealing. The crystalline morphologies, crystallization kinetics,
melting behavior, and crystal structure of the resultant polymers
were investigated by polarized optical microscopy (POM), different
scanning calorimetry (DSC), and X-ray scattering. Constraining the
PEO to the PNB backbone was found to significantly influence the mobility
of PEO chains, the degree of crystallinity, the crystal thickness
and the equilibrium melting point. Increasing the molecular weight
of the PEO or annealing at higher temperature alleviates this constraint
to some extent. In addition to crystallization, the influence of annealing
on the morphology was also investigated.