Simplifying Entangled Polymer Synthesis

At the University of Houston, USA, researchers have recently developed and verified a new route for synthesising superior forms of entangled or knotted polymers with pre-designed characteristics for use in applications such as drug delivery and smart coatings. Using a Viscotek 270max triple detector gel permeation chromatography (GPC) system from Malvern Instruments, the Houston team successfully confirmed the innovative synthesis of interlocking polymer rings (catenanes) by atom transfer radical polymerisation (ATRP) from templated initiators. By combining refractive index (RI), viscosity and light scattering detection, the 270max provides reliable molecular weight data and easy detection of the degree of synthesis throughout the method development, as well as verifying the character of final polymers imaged using atomic force microscopy (AFM).

“The Viscotek 270max is critical to verifying this new method of polymerisation,” explained Professor Rigoberto
Advincula, Department of Chemistry, University of Houston. “These are high molecular weight polymers and ring closure is a thermodynamically difficult reaction that must be done under dilute conditions. Using the triple detection offered by 270max, we were able to effectively characterise the molecular weight of our sample and detect the degree of ring closure  versus the amount of non-closed polymer.”

The University of Houston’s initial success implies that it will be possible to synthesise superior knotted polymers for applications in coatings, lubricants and surface modifiers, among others. In terms of polymer theory, Professor Advincula’s team also plans to make catenated and knotted block copolymers.The project has been funded by the National Science Foundation (USA). A paper outlining the new method is being published in Chemical  Communication from the Royal Society of Chemistry and is now available online.

The Viscotek 270max from Malvern Instruments is a complete, advanced, multidetector GPC/SEC
system suitable for all macromolecular applications, particularly research.