Associating Polymers

The insertion of a relatively small fraction of polar or ionic monomers in a polymer chain that interact via strong short-range specific attractions can strongly modify its dynamic and rheological properties in semi-dilute solutions and melts. There has been increasing interest in such “associative copolymers” due to applications such as self-healing materials, biomaterials, rheological modifiers, sensors, and actuators. The “sticky” groups can attract via H-bonding, coulomb, M-L coordination, charge transfer, and other forces and can be arranged in a regular or random manner along the polymer backbone, as discrete entities or blocks, and at a wide range of mole fractions compared to the “non-sticky” monomers. Depending upon the strength of attraction and temperature, the lifetime of physical bonds can be vastly different, leading to transient network behavior without chain entanglement.

We are interested in creating a microscopic non-equilibrium statistical mechanical theory to understand

• slow dynamics induced by the presence of stickers

• impact on the alpha relaxation and glass transition temperature of the system

• role of strong vs weak-association on the bulk properties of the system

• mechanism of bond-breaking