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Abstract Synthetic plastics sourced from petroleum have gained widespread use since the 1950s. Polystyrene (PS) is one of the most extensively used plastics, as it is colorless, has high mechanical strength, and exhibits excellent chemical and thermal stability; however, it is also one of the least recycled plastics because of the high cost and low profit in recycling. Herein, we demonstrate a mechanochemical recycling approach that allows PS to be efficiently degraded into benzene when it is ground in a ball mill with AlCl₃. For example, when 165 kDa PS pellets are milled with AlCl₃, the extent of degradation reaches 90% at 15 min. Isotope labeling experiments indicate that both ambient water and the polymer backbone can be proton sources for the formation of benzene. The benzene generated in the mechanochemical degradation can be used to synthesize styrene, which can be repolymerized to produce polystyrene, allowing for the closed‐loop recycling of PS. In addition, a mechanochemical Friedel–Crafts acylation between the generated benzene and the subsequently added benzoic anhydride produces benzophenone in 40%–50% yield. The mechanochemical degradation process demonstrated here is solvent‐free, cost‐effective, and energy‐efficient, providing a promising route for the chemical recycling and upcycling of PS. 

Abstract Ever since the inception of synthetic polymeric materials in the late 19th century, the number of studies on polymers as well as the complexity of their structures have only increased. The development and commercialization of new polymers with properties fine‐tuned for specific technological, environmental, consumer, or biomedical applications requires powerful analytical techniques that permit the in‐depth characterization of these materials. One such method with the ability to provide chemical composition and structure information with high sensitivity, selectivity, specificity, and speed is mass spectrometry (MS). This tutorial review presents and exemplifies the various MS techniques available for the elucidation of specific structural features in a synthetic polymer, including compositional complexity, primary structure, architecture, topology, and surface properties. Key to every MS analysis is sample conversion to gas‐phase ions. This review describes the fundamentals of the most suitable ionization methods for synthetic materials and provides relevant sample preparation protocols. Most importantly, structural characterizations via one‐step as well as hyphenated or multidimensional approaches are introduced and demonstrated with specific applications, including surface sensitive and imaging techniques. The aim of this tutorial review is to illustrate the capabilities of MS for the characterization of large, complex polymers and emphasize its potential as a powerful compositional and structural elucidation tool in polymer chemistry. 

Polyfluoroalkyl substances (PFASs) and para-phenylenediamines (PPDs) are emerging classes of anthropogenic contaminants that are environmentally persistent (most often found in ground and surface water sources), bioaccumulative, and harmful to human health. These chemicals are currently regulated in the US by the Environmental Protection Agency (EPA), the Food and Drug Administration (FDA), and the Occupational Safety and Health Administration (OSHA). Analysis of these contaminants is currently spearheaded by mass spectrometry (MS) coupled to liquid chromatography (LC) because of their high sensitivity and separation capabilities. Although effective, a major flaw in LC-MS analysis is its large consumption of solvents and the amount of time required for each experiment. Direct analysis in real time mass spectrometry (DART-MS) is a new technique that offers high sensitivity and permits rapid analysis with little to no sample preparation. Herein, we present the qualitative and quantitative analysis of PFASs and PPDs by high-resolution DART-MS, interfaced with ion mobility (IM) and tandem mass spectrometry (MS/MS) characterization, demonstrating the utility of this multidimensional approach for the fast separation and detection of environmental contaminants. 

The catalytic conversion of carbon dioxide into polymers via high-energy comonomers offers a sustainable, low-cost, and low-emission approach for developing conveniently manufactured high-performance materials without competing for land-use or food resources. We present the synthesis of poly(amidoamine) polymers stoichiometrically derived from carbon dioxide, butadiene, and amines displaying useful mechanical properties (tensile strength 43 MPa, Young’s modulus 840 MPa, and flexural modulus 2.8 GPa). The low viscosity precursors are applicable to producing carbon fiber reinforced polymers with fiber wetting and rapid network formation (16 minutes at 150°C). This work reveals that internal hydrogen-bonding catalyzes the ring-opening polymerization, and the intramolecular alcohol moiety promotes chemical recyclability in acidic conditions, allowing fiber recovery with <1.0 wt % difference from virgin fiber and monomer in 72% yield.