Labeling polymers with 13C isotopes enables precise tracking of carbon during chemical transformations and biodegradation, offering valuable insights into degradation mechanisms and the environmental impact. Nevertheless, the commercial availability of such labeled polymers remains limited. This is primarily due to the lack of 13C-labeled monomers required for synthesizing the corresponding polymers and the high costs associated with their production. These challenges hinder the widespread application of 13C-labeled polymers in research and industry. In this study, we report the successful laboratory synthesis and characterization of 13C stable isotope-enriched polyethylene. Homopolyethylene and copolyethylene samples with an approximate 25 wt % 13C-enrichment were produced by polymerizing mixtures of standard and 13C isotope-labeled ethylene monomers. The characterization of the 13C-labeled polyethylene samples indicated that their microstructural properties were similar to those of the standard polyethylene samples produced from conventional ethylene monomers. Additionally, we present the quantification of 13C isotope enrichment in polyethylene using pyrolysis gas chromatography–mass spectrometry (Py-GCMS), alongside conventional nuclear magnetic resonance (NMR) and isotope ratio mass spectrometry (IRMS) analysis. Our results demonstrate that the 13C isotope enrichment values measured by Py-GCMS are comparable to those obtained from the conventional IRMS method, indicating the potential application of Py-GCMS as an alternative method for 13C isotope analysis in polymer samples.
Chowreddy et al. (Tue,) studied this question.