TY - JOUR
T1 - Evaluation of Organosolv Lignin as an Oxidation Inhibitor in Bitumen
AU - Zhang, Yi
AU - Liu, Xueyan
AU - Apostolidis, Panos
AU - Jing, Ruxin
AU - Erkens, Sandra
AU - Poeran, Natascha
AU - Skarpas, Athanasios
PY - 2020
Y1 - 2020
N2 - Organosolv lignin, a natural polymer, has been used in this study as an oxidation inhibitor in bitumen. Particularly, the effect of oxidative aging on the chemical compositional changes and on the rheology of bituminous binders with organosolv lignin and the impact to inhibit oxidation in bitumen were evaluated. Firstly, after analyzing the microstructure and surface characteristics of utilized organosolv lignin, a high shear mixing procedure was followed to produce binders of different proportions of lignin in bitumen. Pressure aging vessel conditioning was applied to these binders to simulate in-field aging and a series of tests were performed. Fourier transform infrared spectroscopy was used to track the compositional changes of lignin–bitumen systems before and after aging respectively. The rheological changes due to oxidative aging in the different lignin–bitumen systems were studied by means of dynamic shear rheometer tests. Based on the spectroscopic laboratory analyses, certain proportions of organosolv lignin in bitumen have shown a potential oxidation retardation effect in bitumen since a reduction of carbonyl and sulfoxide compounds was observed. However, the addition of lignin reduced the fatigue life of bitumen and potentially led to an increase in brittle fracture sensitivity at low and medium temperatures. Nevertheless, lignin improved the rutting resistance at high temperatures. Overall, it can be concluded that organosolv lignin can suppress the oxidation of sulfur and carbon compounds in bitumen either by direct deceleration of oxidation reaction or interaction with compounds that otherwise are oxidizable, without seriously degrading the mechanical properties.
AB - Organosolv lignin, a natural polymer, has been used in this study as an oxidation inhibitor in bitumen. Particularly, the effect of oxidative aging on the chemical compositional changes and on the rheology of bituminous binders with organosolv lignin and the impact to inhibit oxidation in bitumen were evaluated. Firstly, after analyzing the microstructure and surface characteristics of utilized organosolv lignin, a high shear mixing procedure was followed to produce binders of different proportions of lignin in bitumen. Pressure aging vessel conditioning was applied to these binders to simulate in-field aging and a series of tests were performed. Fourier transform infrared spectroscopy was used to track the compositional changes of lignin–bitumen systems before and after aging respectively. The rheological changes due to oxidative aging in the different lignin–bitumen systems were studied by means of dynamic shear rheometer tests. Based on the spectroscopic laboratory analyses, certain proportions of organosolv lignin in bitumen have shown a potential oxidation retardation effect in bitumen since a reduction of carbonyl and sulfoxide compounds was observed. However, the addition of lignin reduced the fatigue life of bitumen and potentially led to an increase in brittle fracture sensitivity at low and medium temperatures. Nevertheless, lignin improved the rutting resistance at high temperatures. Overall, it can be concluded that organosolv lignin can suppress the oxidation of sulfur and carbon compounds in bitumen either by direct deceleration of oxidation reaction or interaction with compounds that otherwise are oxidizable, without seriously degrading the mechanical properties.
KW - aging
KW - bitumen
KW - chemistry
KW - microstructure
KW - organosolv lignin
KW - oxidation inhibitor
KW - rheology
UR - http://www.scopus.com/inward/record.url?scp=85085636166&partnerID=8YFLogxK
U2 - 10.3390/molecules25102455
DO - 10.3390/molecules25102455
M3 - Article
VL - 25
JO - Molecules: a journal of synthetic organic and natural product chemistry
JF - Molecules: a journal of synthetic organic and natural product chemistry
SN - 1420-3049
IS - 10
M1 - 2455
ER -