SBS Modified Bitumen with Organic Layered Double Hydroxides: Compatibility and Aging Effects on Rheological Properties.

Meng Yu,Ting Wang,Zhengli Yan,Canlin Zhang,Zhenliang Jiang,Shi Xu,Hongjun Dong,Changbin Hu

doi:10.3390/ma14154201

Abstract

SBS-modified bitumen (SMB) is susceptible to aging, which seriously influences its service performance and life. In order to strengthen the anti-aging ability of SMB, triethoxyvinylsilane was designed to organically modify layered double hydroxides (LDHs) and was applied to modify SMB. The dispersibility and storage stability of LDHs in SMB were markedly enhanced after triethoxyvinylsilane organic modification, and the compatibility and storage stability of SBS in bitumen were simultaneously enhanced. Compared with SMB, the introduction of LDHs and organic LDHs (OLDHs) could ameliorate the high-temperature properties of SMB, and the thermostability of SBS in bitumen at a high temperature was also distinctly improved, especially OLDHs. After aging, due to the oxidation of molecular bitumen and the degradation of molecular SBS, SMB became hardened and brittle, and the rheological properties were significantly deteriorated, which had serious impacts on the performance of SMB. LDHs can mitigate the detriment of aging to bitumen and SBS, and the deterioration of the rheological properties of SMB is obviously alleviated. As a result of the better dispersibility and storage stability, OLDHs exerted superior reinforcement of the anti-aging ability of SMB.

Highlights

The unsatisfactory high-temperature and low-temperature performance of base bitumen have promoted the extensive application of styrene-butadiene-styrene (SBS) as a bitumen modifier in highway pavement [1,2,3]
In comparison with SBS-modified bitumen (SMB), it can be observed that the ∆S of LSMB or OLSMB increased, and the tendency became more noticeable with the increasing dosage of layered double hydroxides (LDHs) or organic LDHs (OLDHs), which was due to the sinking of LDHs in bitumen during storage, resulting in the softening point increase of the bottom
The surface hydrophilic groups of LDHs were reduced after silane coupling agent organic modification, which can inhibit the aggregation between LDH particles and improve the dispersiveness in SMB

Summary

Introduction

The unsatisfactory high-temperature and low-temperature performance of base bitumen have promoted the extensive application of styrene-butadiene-styrene (SBS) as a bitumen modifier in highway pavement [1,2,3]. Zhang et al [13] found that a large dosage of sodiummontmorillonite (MMT) can enhance the aging resistance of SMB. The lowtemperature performance of SMB was decreased after adding a large amount of MMT. Feng et al [14] discovered that UV absorbers can reduce the UV aging of SMB, but the Materials 2021, 14, 4201. Materials 2021, 14, 4201 Materials 2021, 14, 4201 montmorillonite (MMT) can enhance the aging resistance of SMB. The low-temperature performance of SMB was decreased after adding a large amount of MM2 Tof.1F2eng et al [14] discovered that UV absorbers can reduce the UV aging of SMB, but the effect of UV absorbers was not universal, which only worked for specific types of SMB. Triethoxyvinylsilane was produced by Shandong Huanzheng Chemical Company Limited (Jinan, China)

Sample Preparation

Aging Procedures

Storage Stability Test

Fluorescence Microscope Test

Rheological Properties Test

Compatibility and Storage Stability

Conclusions