Gel permeation chromatography unit for comprehensive polymer analysis

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Size exclusion chromatography (SEC), alternatively known as gel permeation chromatography (GPC), is universally used to determine the molecular weight distribution of polymeric materials. Knowledge of the molecular weight distribution is essential for relating it to key properties such as viscosity (and in turn processing conditions) and tensile and impact strength, which dictate final use performance. GPC is also a powerful technique for elucidating polymerization mechanisms and with the appropriate detection unit, can supply essential structural information such as coil conformation in solution, degree of branching and tagging of functional groups. All of these features are vital for designing polymers for novel biological delivery systems, next-generation sealants and coatings and materials for composites and microelectronics. For example, all of the projects I am pursuing solely or in collaboration with my co-applicants requires the complete suite of detection capability offered by the GPC unit. These range from non-isocyanate poly(urethanes) without toxic feedstock, self-healing, low viscosity and low volatility aerospace coatings; green plasticizers with improved defect removing features in calendared films, bio-based composites and novel biodegradable polymeric gas hydrate inhibitors/promoters. Consequently, the GPC units must have multiple detectors such as refractive index (to measure concentration and derive the molecular weight distribution relative to polymeric standards) and intrinsic viscosity to reveal branching and solution properties of the polymer. Further, the unique set up of the unit requested allows rapid elution on the order of a few minutes, compared to the nearly one hour of our existing GPC, allowing nearly real-time feedback on the polymerization being studied.  The multiple solvent switching enabled also permits gradient chromatography and rapid changeover for different samples with differing solubilities, without having to change columns.  The configurations requested in this proposal meets the current analytical needs but more importantly, allow my students and collaborators to envision novel future capabilities of GPC to analyze the unique polymers and properties we are building into our materials.