When a material is made using several different monomers, like a styrene/butadiene rubber, ethylene/propylene copolymer or a latex paint, pyrolysis-GC/MS can be a valuable tool in identifying both monomers used and quantitatively determining the relative amounts of each. Whether mixtures, blends, laminates, random or block copolymers, compounds will be produced relating to each of the monomers present, which can be used to study the molecular formula. This is frequently done using copolymers with just a few monomers, each of which represents a significant part of the copolymer. The same method can be used to determine small concentrations of monomers or even trace contaminants. In this application note, a polystyrene copolymer with levels of methyl methacrylate contamination was analyzed.
Polystyrene copolymer, approximately 100μg, containing 0.1%, 0.2% and 0.3% and 0.4% poly(methyl methacrylate) contamination was pyrolyzed to a setpoint of 750°C using a CDS Pyroprobe 6150 to create a calibration curve.
Experimental Setup
Pyroprobe
Model: CDS 6150
Pyrolysis: 750°C 15seconds
Interface: 300°C
Transfer Line: 325°C
Valve Oven: 325°C