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Introduction to Polymer Science and Engineering
Badge A: Polymer Chemistry
Lecture A10-E: Size Exclusion Chromatography ExperimentJames M.
CaruthersGerald and Sarah Skidmore Professor of Chemical
EngineeringPurdue UniversityWest Lafayette, IN
[email protected]
February 17, 2015
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Size Exclusion Chromatography ExperimentWe will now go the
PolySim Virtual Polymer Laboratory to perform the necessary
experimentExperiment Objective:Determine a calibration curve using
a series of polystyrene standards in THF. Then, determine the
number and weight molecular weight of a broad polystyrene sample
(called Polystyrene A in the PolySim interface) using the
calibration curve.
Procedure:Measure the GPC curve of a series of polystyrene
standards in THF. A good concentration for the GPC experiment is 5
mg/ml.Determine peak point elution volume of each standard from GPC
data.Plot the elution volume vs. log(MW) to obtain the calibration
curve.Measure the GPC curve of a broad polystyrene sample.Determine
the broad PS samples number and weight average molecular
weight.
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Measure MWD using GPC
This is the interface of Light Scattering instrument
simulator.
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Measure MWD using GPC
1. Choose your sample vial
3. Set the temperature (30C in this demo)
4. Set the flow rate (1ml/min in this demo) 6. Hit Run button to
see your result
2. Choose Column set (200 mixed THF in this demo)
5. Set the injection volume (0.1ml in this demo)
6. Choose detectors (RI only in this demo)
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Measure MWD using GPC
Hit this button to save your data as csv file
Your result shows at the bottom of the interface.
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Saved csv file will look like this.Construct Spread Sheet
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Construct Spread Sheet
Plot elution volume vs. RI signal and find the peak point
elution volume. 30.4 ml in this case.*Tip : use max and vlookup
function to find the peak point volume.Ex) vlookup(max(RI
signal,RI&V table,V column #, false)
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Construct Spread Sheet
1) Record MW and corresponding Peak volume.2) Plot peak volume
vs. log(MW)3) Add linear fit to obtain the calibration curve.
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Repeat first step using Polystyrene A.Obtain the RI curve of the
sample.Measure MWD of broad sample
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Construct Spread Sheet
Calculate log(MW) using the calibration curve we obtained from
the previous step.
* log(MW)=-0.25V+11.62) Calculate MW from log(MW)
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Construct Spread Sheet
Calculate weight fraction from RI data.
RI signal is proportional to the concentration, where the
normalized RI signal is the weight fraction.
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Construct Spread Sheet
Calculate number fraction from weight fraction.
The normalized number fraction is the weight fraction/MW
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Result
Calculate number and weight average molecular weight.Mn = 5, 410
g/moleMw = 8760 g/molePDI = 1.62
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