High-temperature characterization of polymers with HPLC system having multiple mobile-phase reservoirs

A method for characterizing a polymer sample, the method comprising

• injecting a polymer sample into a mobile-phase of a liquid chromatography system, the mobile-phase being supplied to a liquid chromatography column from a mixing zone, the mixing zone being in fluid communication with a first reservoir containing a first mobile phase fluid at a first temperature, and with a second reservoir containing a second mobile phase fluid at a second temperature,
• controlling the temperature of the mobile-phase in the mixing zone to vary over time by varying the relative amounts of the first and second mobile-phase fluids supplied to the mixing zone,
• separating one or more sample components of the polymer sample in the chromatography column, and
• detecting a property of at least one of the separated sample components.

A liquid chromatography system for characterizing a polymer sample, the system comprising

• an enclosure defining a heated environment, the heated environment being maintained at a temperature of not less than about 75° C.,
• a chromatographic column residing in the heated environment, the chromatographic column comprising a surface defining a pressurizable separation cavity, an inlet port for receiving a mobile phase and for supplying a polymer sample to the separation cavity, an effluent port for discharging the mobile phase and the polymer sample or separated components thereof from the separation cavity, and a stationary-phase within the separation cavity,
• an injection port adaptable for fluid communication with the chromatographic column for injecting polymer samples into the mobile phase,
• a first reservoir for containing a first mobile phase fluid,
• a second reservoir for containing a second mobile phase fluid,
• a mixing zone adaptable for fluid communication with the first reservoir and the second reservoir for mixing of the first and second mobile phases to form a mobile-phase eluant having compositions or temperatures that can vary over time, the mixing zone being further adaptable for fluid communication with the inlet port of the chromatographic column for eluting one or more sample components of the sample with the mobile-phase eluant to separate at least one sample component of the sample from other sample components thereof, and
• a detector in fluid communication with the effluent port of the chromatographic column for detecting a property of at least one of the sample components.