Dynamic networks – Assembly

Crystallization and block polymer assembly

The ability of polymers to crystallize is key to their optical, thermal, and mechanical properties. Polymer networks can typically only crystallize if the molecular weight of the chains between crosslinks is high enough. We have demonstrated that dynamic bonds allow very dense networks to crystallize, and that this leads to anincrease in their percent crystallinity and perfection. Ongoing work is looking to manipulate the kinetics of this process by controlling bond exchange.

The role of bond exchange is also being explored in block polymers, comprised of two immiscible polymers linked by a covalent bond. When the junction is dynamic, blocks can exchange and diffuse as objects of much lower weight compared to the overall copolymer. The block may also randomize to form AA, AB, and BB pairs depending on the precise chemistry employed. Understanding how this process can lead to faster assembly or lower defects is underway.