45 Years of Polymer HPLC: A Short Review

Abstract

Until the end of the 70s of the last century, the major tool for fractionating complex polymers regarding molecular size is gel permeation chromatography (GPC) (more accurately size exclusion chromatography, SEC). A milestone in fractionating polymers with regard to chemical composition is achieved when it is shown that random copolymers can be separated according to copolymer composition using solvent gradient HPLC. Another important step toward selective fractionation is taken when liquid chromatography at the critical point of adsorption is introduced as an efficient way to separate functional polymers with regard to their functionality type distribution. Another milestone is the discovery that temperature gradients can also be used for the selective separation of complex polymers with regard to composition. The combination of different LC methods in comprehensive 2D HPLC setups is another milestone. As of today, a toolbox of HPLC methods is in place that enables the fractionation of complex polymers according to all molecular parameters including tacticity and branching. Here, an overview on the different techniques and some major applications is presented. The most important developments in the field are discussed, and different techniques, experimental protocols, and applications are highlighted. In conclusion, challenges for future developments are outlined.