This document introduces the characteristics of polystyrene products, including molecular weight and molecular weight distribution.
Polystyrenes are widely used for packaging and other materials, and their properties depend on monomers and molecular weights. The document illustrates how injection moulding processes affect polystyrene properties, showing significant changes in molecular weight distribution after grinding and re-moulding chips compared to the original granulate.
To characterize these small differences reliably, the Agilent 1100 Series GPC-SEC system is required. The note details the specific equipment used, including the vacuum degasser, isocratic pump, autosampler, thermostatted column compartment, and refractive index detector, along with the ChemStation Plus software for data analysis.
| Column | 3 x PLgel mixed B, 7.5 x 300 mm, 10 um |
|---|---|
| Mobile phase | Tetrahydrofuran |
| Flow rate | 1.0 mL/min |
| Column compartment temperature | 20°C |
| Injection volume | 10 ul |
| Detector | Refractive index detector, alternatively VWD, 254 nm |
A GPC-SEC instrument with excellent precision, such as the Agilent 1100 Series GPC-SEC system.
Polystyrene EasyCal Vial standards (Agilent p/n 79911-60500 and 79911-60501) were used.