Characterization of High Molecular Weight poly(p-phenylenethynylene)s by Pyrolysis Gas Chromatopography/Mass Spectometry With Multivariate Data Analysis

Pyrograms of the different polymers contained peaks both common to the group of polymers analyzed and unique to the different side groups. Substituted PPEs can be identified by the presence of these chemical markers as degradation products in the pyrograms. Principal component analysis was applied to the multivariate Py-GC/MS data, and differences between the substituted PPEs were visually apparent in PCA projections. GC/MS patterns have also been applied to the data from these polymers. Analytical pyrolysis followed by GC/MS is a particularly useful tool for qualitative or quantitative analysis of polymeric materials that are not amenable for GC or MS analysis. These materials have applications in the optical and electronic industries and have been recently synthesized by alkyne metathesis of 1,4-dipropynylated benzenes. Structural aspects of interest for characterization include identifying the presence of substituent side-chains, identification of end groups, determining the polymer molecular weight, and diagnosing structural defects. Materials and methods are described in detail. 11 figures and 23 references