Study on Ultraviolet Aging Mechanism of Carbon Nanotubes/SBS Composite-Modified Asphalt in Two-Dimensional Infrared Correlation Spectroscopy

Abstract

In order to explore the influence mechanism of carbon nanotubes on the ultraviolet (UV) aging properties of the SBS-modified asphalt binder, the changes of functional groups in the one-dimensional infrared spectrum and two-dimensional infrared correlation spectrum are studied in this paper. The results show that the UV aging process of the SBS-modified asphalt binder is the process of alkane chain cleavage and reorganization, the formation of oxygen-containing functional groups and decomposition of SBS. The incorporation of carbon nanotubes can reduce the mutual conversion of methyl and methylene functional groups, inhibit the decomposition of butadiene and the destruction of C = C double bonds in SBS. The degradation of SBS during the process of UV aging leads to the change of many functional groups and acceleration of the aging of the SBS-modified asphalt binder. The addition of carbon nanotubes can effectively alleviate the degradation of SBS and the formation of oxygen-containing functional groups at the early stage of UV aging, and reduce the influence of these two changes on other functional groups; thus, improving the anti-aging performance of the SBS-modified asphalt binder.

A Janus membrane doped with carbon nanotubes for wet–thermal management

“…A C C stretching vibration peak appearing at 1650 cm −1 of the CNTs@CA fibrous membrane could be attributed to sp 2 hybridization of the carbon–carbon double bonds in CNTs. 45 These phenomena indicated that CNTs were well doped.…”

A Multistage Analysis of Asphalt Binder Nanocrack Generation and Self-Healing Behavior Based on Molecular Dynamics

“…In order to verify the reliability of the asphalt binder model, Table 3 presents the simulated and experimental data of the (i) density, (ii) glassy transition temperature, (iii) solubility parameters and (iv) diffusion coefficient. As an important index in molecular simulation, the density of the asphalt binder model at 298.15 K is 0.981 (g/cm 3 ), which is lower than the density of 1.01-1.04 (g/cm 3 ) obtained in the experiment, which may be due to the excessive complexity of the asphalt binder components, and the asphalt binder model constructed with 12 representative molecules cannot fully represent the complex composition of the actual asphalt materials.…”

“…After establishing 12 representative molecules of AAA-1 asphalt binder, the combined model of AAA-1 asphalt binder was established by Packmol; the initial model size was 140 Å × 140 Å × 140 Å, and the density was approximately equal to 0.1 g/cm 3 . The simulation steps used in this paper are shown in Table 2.…”

“…In the early stage of cracks in the asphalt pavement, the nanocracks inside the asphalt material have little impact on the smoothness and driving comfort of the pavement. However, in a humid environment, these nanocracks will expand and cause water damage and other diseases, which will seriously affect the performance and longevity of the pavements [3,4]. Current researchers tend to use two methods to avoid asphalt pavement cracking failure, by developing stronger asphalt pavement materials or studying the healing properties of asphalt pavement materials.…”

Infrared spectroscopic monitoring of solid-state processes

“…The use of IR spectroscopy to monitor non-thermal decomposition and chemical alterations of materials involve the study of UV aging of asphalt involving carbon nanotubes/polystyrene composite, 370 as well as alterations of microplastics, 371 discharge-initiated decomposition of SF6, 372 and environmental degradation of various real-world materials. 373,374 The experiments in transmission mode usually require the use of alkaline halogenide matrix materials, most commonly KBr.…”