摘要
胶粉颗粒在热沥青中会发生溶胀、溶解导致体积膨胀和质量衰减,为了分析胶粉颗粒变化对橡胶沥青粘度的影响,采用搅拌工艺在不同的条件下制备了橡胶沥青,分析了胶粉体积膨胀率(VR)、质量衰减率(T)以及颗粒变化复合指数(φ)等参数与橡胶沥青粘度的关系。并采用筛析方法分离胶粉得到沥青样品,通过红外光谱(IR)探析了橡胶沥青物化作用行为。结果表明,VR和T可以分别表征胶粉颗粒在沥青中的体积膨胀程度和质量衰减,φ可以有效表征胶粉在橡胶沥青体系的综合颗粒变化。φ与橡胶沥青的粘度变化趋势一致,二者呈良好的指数关系。随着制备温度的升高,φ与橡胶沥青的粘度均先增大后减小,在180℃条件下达到峰值,即胶粉溶胀和溶解作用对粘度的贡献最大,温度继续升高会导致胶粉充分溶解并局部降解导致质量衰减,膨胀率有所降低,橡胶沥青粘度减小。在此过程中,部分橡胶分子发生断链降解,特征官能团吸收峰大幅增强,降解程度与制备温度和时间密切相关。由胶粉颗粒体积膨胀引起位阻效应和溶解改性引起的沥青相粘滞增强是橡胶沥青粘度的主要来源。
Swelling and dissolution of crumb rubber exist in hot asphalt,resulting in volume expansion and mass attenuation.To analyze the effect of particle changes of crumb rubber on the viscosity of rubber asphalt,the stirring process was used to prepare rubber asphalt under different conditions.And the relationship between the parameters of volume expansion ratio(VR),mass attenuation ratio(T)and particle change composite index(φ)of crumb rubber particle and the viscosity of rubber asphalt was analyzed.Infrared spectroscopy(IR)analysis was conducted on the asphalt samples separated from crumb rubber to ascertain the phy-chemical behavior.The results show that the parameters VRand T can respectively reflect the volume expansion and mass attenuation degrees of rubber particles in asphalt,and the indexφcan effectively characterize the comprehensive particle changes of crumb rubber in rubber-asphalt system.The variation trend of the parameterφis consistent with the viscosity of rubber asphalt,and the two have a good exponential relationship.With the increase of preparation temperature,φand the viscosity of rubber asphalt both increase first and then decrease,and the peak values appear at 180℃,that is,the comprehensive effect of swelling and dissolution of crumb rubber contributes the most to the viscosity.The rising temperature will lead to adequate dissolution and partial degradation of rubber with mass attenuation,which cause that the volume expansion rate and the viscosity of rubber asphalt decrease.In the process,some of rubber molecules are degraded by chain breaking,and the absorption peaks of typical functional groups are significantly enhanced.The degradation degree is closely related to the preparation temperature and time.The steric hindrance of rubber particles caused by the volume expansion and the viscosity enhancement of asphalt phase caused by the dissolution and modification of rubber molecules are the main sources of viscosity for rubber asphalt.
作者
丁湛
王爱波
栗慧峰
张琳青
丁双
DING Zhan;WANG Ai-bo;LI Hui-feng;ZHANG Lin-qing;DING Shuang(School of Water and Environment,Chang’an University,Xi’an 710054,China;Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region,Ministry of Education,Chang’an University,Xi’an 710054,China;School of Highway,Chang’an University,Xi’an 710064,China;Industry and Information Technology Department of Shaanxi Province,Xi’an 710006,China)
出处
《应用化工》
CAS
CSCD
北大核心
2023年第2期350-354,共5页
Applied Chemical Industry
基金
国家自然科学基金(52278426)
陕西省自然科学基金项目(2019JM195)
陕西省重点研发计划项目(2022SF-169)
中央高校基本科研业务费项目(300102212206)。
关键词
橡胶沥青
胶粉
颗粒变化
体积膨胀率
质量衰减率
复合指数
rubber asphalt
crumb rubber
particle change
volume expansion ratio
mass attenuation ratio
composite index
