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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.
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Glass‐transition temperature governs the thermal decrosslinking behavior of Diels–Alder crosslinked polymethacrylate networks
ABSTRACT A series of Diels–Alder (DA) crosslinked polymethacrylate networks covering a broad range of glass‐transition temperatures (Tg) was prepared to establish the relationship between theTgand the thermal decrosslinking behavior of these networks. A series of permanently crosslinked and uncrosslinked analogues were also prepared to better understand the thermoset‐to‐thermoplastic transition occurring in the DA networks at elevated temperatures. The network series were studied using dynamic mechanical analysis, which established an inverse relationship betweenTgand decrosslinking ability. Differential scanning calorimetry confirmed the viability of the DA linkages in all formulations, and a trapping experiment with 9‐anthracenemethanol demonstrated that even the least responsive network was capable of undergoing decrosslinking given appropriate thermal treatment. While polymer chain mobility has long been understood to be a critical factor in healable materials, this work verifies the importance of this parameter in the decrosslinking of DA networks. © 2019 Wiley Periodicals, Inc. J. Polym. Sci.2020,58, 193–203
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- Award ID(s):
- 1904631
- PAR ID:
- 10457576
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Polymer Science
- Volume:
- 58
- Issue:
- 1
- ISSN:
- 2642-4150
- Page Range / eLocation ID:
- p. 193-203
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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