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ABSTRACT High sulfur‐content materials (HSMs) prepared via inverse vulcanization are attractive for a range of sustainable material applications, particularly when synthesized from waste‐derived feedstocks such as brown grease (BG). Two BG‐based composites,SunBG₉₀andaBG₉₀, were prepared using elemental sulfur and either native or allylated brown grease, respectively. This study explores the effect of reinforcing these sulfur‐rich networks with low loadings (0.5–2 wt. %) of highcis‐1,4‐content liquid polybutadiene (PBD). Incorporation of PBD resulted in significant increases in storage modulus, with a near‐linear relationship between PBD content and stiffness enhancement for both material types. At −60°C, storage modulus increased more than fivefold foraBG₉₀and more than tripled forSunBG₉₀. In contrast, flexural strength and flexural modulus exhibited non‐linear responses, with diminishing or reversed gains at higher PBD loadings, suggesting limits to rubber domain compatibility and dispersion. Thermal analysis confirmed high decomposition temperatures (212°C–226°C) and stable glass transitions, indicating thermal robustness of the reinforced networks. Compared with previous studies requiring higher PBD loadings, these results demonstrate that BG‐based HSMs can be effectively reinforced at low additive levels, offering mechanically robust, low‐cost, and renewable alternatives for structural applications. 

Abstract Herein high-strength composites are prepared from elemental sulfur, sunflower oil, and wastewater sludge. Fats extracted from dissolved air flotation (DAF) solids were reacted with elemental sulfur to yield compositeDAFS(10 wt% DAF fats and 90 wt% sulfur). Additional composites were prepared from DAF fat, sunflower oil and sulfur to giveSunDAF_x(x = wt% sulfur, varied from 85–90%). The composites were characterized by spectroscopic, thermal, and mechanical methods. FT-IR spectra revealed a notable peak at 798 cm^–1indicating a C–S stretch inDAFS,SunDAF₉₀, andSunDAF₈₅indicating successful crosslinking of polymeric sulfur with olefin units. SEM/EDX analysis revealed homogenous distribution of carbon, oxygen, and sulfur inSunDAF₉₀andSunDAF₈₅. The percent crystallinity exhibited byDAFS(37%),SunDAF₉₀(39%), andSunDAF₈₅(45%) was observed to be slightly lower than that of previous composites prepared from elemental sulfur and fats and oils.DAFSandSunDAF_xdisplayed compressive strengths (26.4–38.7 MPa) of up to 227% above that required (17 MPa) of ordinary Portland cement for residential building foundations. The composite decomposition temperatures ranged from 211 to 219 °C, with glass transition temperatures of − 37 °C to − 39 °C. These composites thus provide a potential route to reclaim wastewater organics for use in value-added structural materials having mechanical properties competitive with those of commercial products. 

Abstract The valorization of waste‐derived feedstocks for polymer synthesis represents a sustainable alternative to petroleum‐based materials. In this study, brown grease, a low‐value waste lipid source, is utilized as a precursor for polyol monomer synthesis via a two‐step functionalization process. Transesterification of brown grease with allyl alcohol generates allyl esters, which are subsequently modified via thiol‐ene click chemistry with 2‐mercaptoethanol to yield hydroxyl‐functionalized polyols (BG‐diol). The thiol‐ene reaction proceeds under mild UV‐initiated conditions, achieving high conversion efficiency (>90%) while preserving the structural integrity of the derived polyol.BG‐diolis further polymerized with 4,4′‐methylene diphenyl diisocyanate (MDI) through step‐growth polymerization to form brown grease‐derived polyurethane (BG‐PU). Comparative analysis ofBG‐PUwith polyurethane (PU) synthesized from purified oleic acid (OLA‐PU) demonstrates comparable molecular weight distributions (M_n = 14.4 kDa,M_w = 20.4 kDa forBG‐PU) and thermal properties (T_g = 24 °C,T_d,5%= 270 °C forBG‐PU). These results underscore the feasibility of brown grease as a cost‐effective and renewable alternative to plant oil‐based polyols, offering a pathway toward sustainable PU production while mitigating food security concerns. This approach exemplifies the potential of waste lipids in circular economy strategies for high‐performance polymer synthesis. 

Over 80 MT of elemental sulfur, a byproduct of fossil fuel desulfurization, are generated annually. This has spurred the development of high sulfur content materials (HSMs) via inverse vulcanization as a productive pathway towards sulfur utilization. In this study, we evaluate the antimicrobial performance of SunBG90, an HSM made from brown grease and sulfur, as tiles or infused into fabric squares. The static antimicrobial activity of SunBG90 tiles was assessed, revealing excellent efficacy against Gram-positive bacteria, with reductions of 96.84% for Staphylococcus aureus and 91.52% for Listeria monocytogenes. The tiles also exhibited strong antifungal activity, reducing Candida auris by 96.20% and mold (fumigatus) by 83.77%. In contrast, efficacy against Gram-negative bacteria was more variable, with moderate reductions for Escherichia coli (61.10%) and Salmonella enteritidis (62.15%), lower activity against Campylobacter jejuni and Salmonella typhi, and no effect on Clostridium perfringens. Under dynamic conditions, SunBG90-infused fabrics achieved a near-complete inhibition of L. monocytogenes (99.91%) and high reduction of E. coli (98.49%), along with a 96.24% inhibition of Candida auris. These results highlight the potential and limitations of SunBG90 for antimicrobial applications, emphasizing the need for further optimization to achieve consistent broad-spectrum activity. 

Post-polymerization modification with rigid aryl dithiols enables systematic control over the thermal and mechanical properties of guaiacol-derived high sulfur-content materials. 

ABSTRACT Brown grease (BG) is a high‐free fatty acid (FFA) waste coproduct from the food industry that remains largely unexploited. Herein, we describe a design strategy to upcycle BG into high sulfur‐content materials (HSMs) via inverse vulcanization, circumventing the need for costly transition metals or food‐grade compatibilizers. First, BG was esterified with methyl or allyl groups, yielding MeBG and aBG, respectively. This modification masked the polar carboxylic acids and enhanced miscibility with molten sulfur. Subsequent inverse vulcanization produced remeltable HSMs at 80 or 90 wt% sulfur with uniform elemental distributions by SEM–EDX. FT‐IR spectroscopy revealed the consumption of C=C moieties and the formation of C–S bonds, signifying robust cross‐linking. Thermal analysis (TGA, DSC) indicated good thermal stability (T_d,5%up to 223°C) and glass transitions characteristic of polysulfide networks. Mechanical evaluations demonstrated compressive strengths up to 19.2 MPa, exceeding the minimum requirement for residential foundation‐grade cement (17 MPa) and rivaling previously reported HSMs containing similarly high sulfur content. Notably, MeBG and aBG incorporate organics comprising up to 97 wt% BG, significantly improving the upcycled mass efficiency relative to earlier BG‐based composites. This esterification‐driven approach thus offers a practical, scalable pathway to convert low‐value BG into advanced materials with tunable thermomechanical properties. 

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

This study evaluates the use of post-consumer fast-food restaurant waste and elemental sulfur to create high-strength composite materials. Compressive strengths exceed those of C62 building brick and flexural strengths are competitive with OPC. 

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 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.