Song Xu , Xiangjie Niu , Shaoxu Cai , Bingtao Xu , Lei Fang , Zhilong Cao , Canlin Zhang , Hongyan Ma
{"title":"Investigation on active rejuvenation mechanism of aged SBS modified bitumen: Insights from experiments and molecular dynamics","authors":"Song Xu , Xiangjie Niu , Shaoxu Cai , Bingtao Xu , Lei Fang , Zhilong Cao , Canlin Zhang , Hongyan Ma","doi":"10.1016/j.polymdegradstab.2025.111336","DOIUrl":null,"url":null,"abstract":"<div><div>SBS modified bitumen (SMB) is widely used for its excellent physical and rheological properties, but it is susceptible to aging due to exposure to environmental factors such as heat, light, and oxygen. This aging process involves bitumen aging and SBS degradation, which complicates the rejuvenation of SMB. In order to explore the rejuvenation mechanism of aged SMB, particularly emphasizing the rejuvenation effects of epoxy compounds (BUDGE, TMPGE, and RDGE), a combination of molecular dynamics simulation and experiments was employed. The thermodynamic, chemical, and physical properties of rejuvenated SMB were analyzed. Results show that BUDGE and its repaired SBS exhibit excellent flexibility compared to TMPGE, improving cohesive energy density and free volume of aged bitumen, which facilitates recovery of ductility in aged SMB. Conversely, SBS repaired with RDGE increases cohesive energy density of aged SMB while reducing free volume, which enhances stiffness of bitumen. Additionally, rigid groups in RDGE inhibit mobility of both itself and the repaired SBS, leading to a reduction in the ductility of aged SMB to 10.1 cm. Besides, SBS repaired with RDGE shows strongest binding with resins and aromatics, which diminishes lubricating effect of these components on asphaltenes. This reduction in lubrication enhances aggregation of asphaltenes, ultimately raising flow resistance.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"238 ","pages":"Article 111336"},"PeriodicalIF":6.3000,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Polymer Degradation and Stability","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0141391025001661","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
SBS modified bitumen (SMB) is widely used for its excellent physical and rheological properties, but it is susceptible to aging due to exposure to environmental factors such as heat, light, and oxygen. This aging process involves bitumen aging and SBS degradation, which complicates the rejuvenation of SMB. In order to explore the rejuvenation mechanism of aged SMB, particularly emphasizing the rejuvenation effects of epoxy compounds (BUDGE, TMPGE, and RDGE), a combination of molecular dynamics simulation and experiments was employed. The thermodynamic, chemical, and physical properties of rejuvenated SMB were analyzed. Results show that BUDGE and its repaired SBS exhibit excellent flexibility compared to TMPGE, improving cohesive energy density and free volume of aged bitumen, which facilitates recovery of ductility in aged SMB. Conversely, SBS repaired with RDGE increases cohesive energy density of aged SMB while reducing free volume, which enhances stiffness of bitumen. Additionally, rigid groups in RDGE inhibit mobility of both itself and the repaired SBS, leading to a reduction in the ductility of aged SMB to 10.1 cm. Besides, SBS repaired with RDGE shows strongest binding with resins and aromatics, which diminishes lubricating effect of these components on asphaltenes. This reduction in lubrication enhances aggregation of asphaltenes, ultimately raising flow resistance.
期刊介绍:
Polymer Degradation and Stability deals with the degradation reactions and their control which are a major preoccupation of practitioners of the many and diverse aspects of modern polymer technology.
Deteriorative reactions occur during processing, when polymers are subjected to heat, oxygen and mechanical stress, and during the useful life of the materials when oxygen and sunlight are the most important degradative agencies. In more specialised applications, degradation may be induced by high energy radiation, ozone, atmospheric pollutants, mechanical stress, biological action, hydrolysis and many other influences. The mechanisms of these reactions and stabilisation processes must be understood if the technology and application of polymers are to continue to advance. The reporting of investigations of this kind is therefore a major function of this journal.
However there are also new developments in polymer technology in which degradation processes find positive applications. For example, photodegradable plastics are now available, the recycling of polymeric products will become increasingly important, degradation and combustion studies are involved in the definition of the fire hazards which are associated with polymeric materials and the microelectronics industry is vitally dependent upon polymer degradation in the manufacture of its circuitry. Polymer properties may also be improved by processes like curing and grafting, the chemistry of which can be closely related to that which causes physical deterioration in other circumstances.