TY - JOUR
T1 - Turning two waste streams into one solution for enhancing sustainability of the built environment
AU - Zakertabrizi, Mohammad
AU - Hosseini, Ehsan
AU - Sukumaran, Suja
AU - Korayem, Asghar Habibnejad
AU - Fini, Elham H.
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/11
Y1 - 2021/11
N2 - This study reveals a synergy between an industrial waste (sulfur) and an urban waste (waste cooking oil). It further explores how sulfur binds to hydrocarbon derivatives in the presence of waste cooking oil to create a solution for enhancing sustainability of the built environment. Here, we chose a high-sulfur bitumen (hydrocarbons of high molecular weight) modified with a waste cooking oil rich in alkenes. Changes in the physicochemical and rheological properties of bitumen were used to track the extent of sulfur's binding to hydrocarbon derivatives. The study results show that sulfur radicals attack the double bonds of bio-oil molecules leading to an addition reaction. Our analysis via Density Functional Theory (DFT) showed the latter reaction involves a two-step process: first, the sulfur radical attacks alkene groups of bio-oils; and second, the reaction stabilizes the resulting molecule. It was also showed that the second step releases four times the free energy of the first radical attack. The latter addition reaction leads to strong intermolecular interactions and formation of sulfur-carbon bonds within the bitumen matrix, enhancing bitumen's rheological properties and subsequently its performance properties. Our computational modeling was supported by spectroscopic and rheometric analysis showing an increase in sulfur-carbon bonds as well as a significant increase in bitumen's complex shear modulus. Study results provide comprehensive insights into the stabilization of sulfur elements within bitumen modified with waste cooking oil. Considering that sulfur is a major indusial waste and waste cooking oil is a major urban waste, their synergistic application in bituminous composites mostly used in outdoor construction promotes resource conservation and sustainability of the built environment.
AB - This study reveals a synergy between an industrial waste (sulfur) and an urban waste (waste cooking oil). It further explores how sulfur binds to hydrocarbon derivatives in the presence of waste cooking oil to create a solution for enhancing sustainability of the built environment. Here, we chose a high-sulfur bitumen (hydrocarbons of high molecular weight) modified with a waste cooking oil rich in alkenes. Changes in the physicochemical and rheological properties of bitumen were used to track the extent of sulfur's binding to hydrocarbon derivatives. The study results show that sulfur radicals attack the double bonds of bio-oil molecules leading to an addition reaction. Our analysis via Density Functional Theory (DFT) showed the latter reaction involves a two-step process: first, the sulfur radical attacks alkene groups of bio-oils; and second, the reaction stabilizes the resulting molecule. It was also showed that the second step releases four times the free energy of the first radical attack. The latter addition reaction leads to strong intermolecular interactions and formation of sulfur-carbon bonds within the bitumen matrix, enhancing bitumen's rheological properties and subsequently its performance properties. Our computational modeling was supported by spectroscopic and rheometric analysis showing an increase in sulfur-carbon bonds as well as a significant increase in bitumen's complex shear modulus. Study results provide comprehensive insights into the stabilization of sulfur elements within bitumen modified with waste cooking oil. Considering that sulfur is a major indusial waste and waste cooking oil is a major urban waste, their synergistic application in bituminous composites mostly used in outdoor construction promotes resource conservation and sustainability of the built environment.
KW - Bio-oil
KW - Bitumen
KW - Inverse vulcanization
KW - Polymerization
KW - Sulfur
KW - Waste cooking oil
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U2 - 10.1016/j.resconrec.2021.105778
DO - 10.1016/j.resconrec.2021.105778
M3 - Article
AN - SCOPUS:85111799228
SN - 0921-3449
VL - 174
JO - Resources, Conservation and Recycling
JF - Resources, Conservation and Recycling
M1 - 105778
ER -