Chemistry Reference
In-Depth Information
physical property performance as well as morphology and processing behavior. The
recent development of multiple hydrogen bonding groups that associate more
strongly than single hydrogen bonds has led to greater control of physical and mech-
anical properties.
The introduction of hydrogen bonding groups in block copolymers leads to
increased hydrogen bonding interactions through locally increased hydrogen
bonding group concentration and cooperativity of the hydrogen bonding groups.
The microphase separation in hydrogen bond containing block copolymers often
exhibits greater temperature dependence, and ODTs are linked directly to the hydro-
gen bonding phenomenon. In the case of complementary hydrogen bonding groups,
such as nucleobases, the introduction of guest molecules and complexation of comp-
lementary polymer blocks is achievable. Interesting morphologies are observed in
both the solution and solid state for hydrogen bonding block copolymers.
Telechelic hydrogen bonding functionality has been the focus of great attention in
recent years. Telechelic functionality results in a simpler system for studying hydro-
gen bonding, although microphase separation can still complicate the system in the
solid state. Self-complementary quadruple hydrogen bonding UPy groups have
been a strong focus in this area. Solution rheology is a particularly powerful tool
for studying these systems, and both concentration and the present of “chain
blocker” monofunctional hydrogen bonding groups control the effective molecular
weight in solution.
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