1. Thermoreversible Supramolecular Architecture for Improved Melt Processibility and Performance
Emily B. Anderson and Timothy E. Long, Department of Chemistry, Virginia Tech, Blacksburg, VA 24061
Complementary, Thermoreversible Hydrogen-bonding of Polymers on Surfaces
Synthesis of Phosphonium Ion-containing Polyesters for Thermoreversible Ionic Aggregation hv
H-bonding Functionality
Blocking Group
Complimentary H-bonding Functionality n m
Commercial viability of polyesters requires facile melt processing. Synthesis of phosphonium-based ionomers with only weak ionic interactions and sterically hindered cations may maintain facile processing of high impact polyesters and other high performance polymers while improving mechanical performance. Phosphonium-based telechelic polymers were prepared, and melt rheology indicates only weak to no ionic interactions above 120 °C.
The introduction of ionic and hydrogen bonding functionalities into polymers provides thermoreversible sites. Thymine and adenine are complementary hydrogen bonding groups. Protecting thymine with photocleavable nitrobenzyl groups prevents hydrogen bonding, and a photomask and 365 nm light can be used to selectively cleave nitrobenzyl groups off of surface-grafted thymines for preparation of patterned hydrogen bonding with adenine-based polymers.