2 research outputs found
Structure and Mechanical Properties of Polybutadiene Thin Films Bound to Surface-Modified Carbon Interface
The
structure and mechanical properties of polybutadiene (PB) films
on bare and surface-modified carbon films were examined. There was
an interfacial layer of PB near the carbon layer whose density was
higher (lower) than that of the bulk material on the hydrophobic (hydrophilic)
carbon surface. To glean information about the structure and mechanical
properties of PB at the carbon interface, a residual layer (RL) adhering
to the carbon surface, which was considered to be a model of “bound
rubber layer”, was obtained by rinsing the PB film with toluene.
The density and thickness of the RLs were identical to those of the
interfacial layer of the PB film. In accordance with the change in
the density, normal stress of the RLs evaluated by atomic force microscopy
was also dependent on the surface free energy: the RLs on the hydrophobic
carbon were hard like glass, whereas those on the hydrophilic carbon
were soft like rubber. Similarly, the wear test revealed that the
RLs on the hydrophilic carbon could be peeled off by scratching under
a certain stress, whereas the RLs on the hydrophobic carbons were
resistant to scratching
Nanostructures and Dynamics of Macromolecules Bound to Attractive Filler Surfaces
We report in situ nanostructures
and dynamics of polybutadiene
(PB) chains bound to carbon black (CB) fillers (the so-called “bound
polymer layer (BPL)”) in a good solvent. The BPL on the CB
fillers was extracted by solvent leaching of a CB-filled PB compound
and subsequently dispersed in deuterated toluene to label the BPL
for small-angle neutron scattering and neutron spin echo techniques.
The results demonstrate that the BPL is composed of two regions regardless
of molecular weights of PB: the inner unswollen region of ≈
0.5 nm thick and outer swollen region where the polymer chains display
a parabolic profile with a diffuse tail. In addition, the results
show that the dynamics of the swollen bound chains can be explained
by the so-called “breathing mode” and is generalized
with the thickness of the swollen BPL