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Herein we report the preparation of high sulfur-content materials (HSMs) using food waste and elemental sulfur. 

Abstract Poly(methyl methacrylate) (PMMA) is an important commodity polymer having a wide range of applications. Currently, only about 10% of PMMA is recycled. Herein, a simple two‐stage process for the chemical upcycling of PMMA is discussed. In this method PMMA is modified by transesterification with a bio‐derived, olefin‐bearing terpenoid, geraniol. In the second stage, olefin‐derivatized PMMA is reacted with sulfur to form a network composite by an inverse vulcanization mechanism. Inverse vulcanization of PGMA with elemental sulfur (90 wt.%) yielded the durable compositePGMA‐S. This composite was characterized by NMR spectrometry, IR spectroscopy, elemental analysis, thermogravimetric analysis, and differential scanning calorimetry. Composite water uptake, compressional strength analysis, flexural strength analysis, tensile strength analysis, and thermal recyclability are presented with comparison to current commercial structural materials.PGMA‐Sexhibits a similar compressive strength (17.5 MPa) to that of Portland cement.PGMA‐Sdemonstrates an impressive flexural strength of 4.76 MPa which exceeds the flexural strength (>3 MPa) of many commercial ordinary Portland cements. This study provides a way to upcycle waste PMMA through combination with a naturally‐occurring olefin and industrial waste sulfur to yield composites having mechanical properties competitive with ecologically detrimental legacy building materials. 

High sulfur-content materials (HSMs) formed via inverse vulcanization of elemental sulfur with animal fats and/or plant oils can exhibit remarkable mechanical strength and chemical resistance, sometimes superior to commercial building products. Adding pozzolan fine materials—fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBFS), or metakaolin (MK)—can further improve HSM mechanical properties and stability. Herein, we detail nine materials comprised of rancidified chicken fat, elemental sulfur, and canola or sunflower oil (to yield CFS or GFS, respectively) and, with or without FA, SF, GGBFS, or MK. The base HSMs, CFS90 or GFS90, contained 90 wt% sulfur, 5 wt% chicken fat, and 5 wt% canola or sunflower oil, respectively. For each HSM/fine combination, the resulting material was prepared using a 95:5 mass input ratio of HSM/fine. No material exhibited water uptake >0.2 wt% after immersion in water for 24 h, significantly lower than the 28 wt% observed with ordinary Portland cement (OPC). Impressively, CFS90, GFS90, and all HSM/fine combinations exhibited compressive strength values 15% to 55% greater than OPC. After immersion in 0.5 M H2SO4, CFS90, GFS90, and its derivatives retained 90% to 171% of the initial strength of OPC, whereas OPC disintegrated under these conditions. CFS90, GFS90, and its derivatives collectively show promise as sustainable materials and materials with superior performance versus concrete. 

Abstract Environmental damage caused by waste plastics and downstream chemical breakdown products is a modern crisis. Endocrine‐disrupting bisphenol A (BPA), found in breakdown products of poly(bisphenol A carbonate) (PC), is an especially pernicious example that interferes with the reproduction and development of a wide range of organisms, including humans. Herein we report a single‐stage thiocracking method to chemically upcycle polycarbonate using elemental sulfur, a waste product of fossil fuel refining. Importantly, this method disintegrates bisphenol A units into monoaryls, thus eliminating endocrine‐disrupting BPA from the material and from any potential downstream waste. Thiocracking of PC (10 wt%) with elemental sulfur (90 wt%) at 320 °C yields the highly crosslinked networkSPC₉₀. The composition, thermal, morphological, and mechanical properties ofSPC₉₀were characterized by FT‐IR spectroscopy, TGA, DSC, elemental analysis, SEM/EDX, compressive strength tests, and flexural strength tests. The compositeSPC₉₀(compressive strength = 12.8 MPa, flexural strength = 4.33 MPa) showed mechanical strengths exceeding those of commercial bricks and competitive with those of mineral cements. The approach discussed herein represents a method to chemically upcycle polycarbonate while deconstructing BPA units, and valorizing waste sulfur to yield structurally viable building materials that could replace less‐green legacy materials.