针对不同微波辐照时间对废轮胎胶粉（CR）的改性效果进行了研究。利用抽提法、凝胶渗透色谱及低场核磁共振技术测得的溶胶质量分数及交联密度来表征不同辐照时间的微波改性效果。采用FT-IR、SEM等方法检测微波辐照前后的废轮胎胶粉的结构及形貌变化。结果表明，微波功率为700 W、样品质量为40.0 g、辐照时间为5 min时，样品的溶胶质量分数增加，交联密度最低。微波能够促使C—S、S—S等交联键断裂，胶粉表面空隙增大，胶粉活化。但微波作用时间过长，样品交联密度增大，交联结构再生速率加快，改性效果变差。

Effects of microwave exposure time on modification behaviors of crumb rubber are studied.The influence of exposure time on microwave modification effect is characterized through sol content determined by both Soxhlet extraction and gel permeation chromatography, and crosslinking density obtained by LF-NMR.Structural and morphological changes of crumb rubber before and after microwave irradiation are characterized by FTIR and SEM.It is found that the sol content in samples will increase and the crosslinking density will decrease to the lowest when the microwave power is 700 W, sample mass is 40.0 g and exposure time is 5 min.Microwave treatment can promote C-S and S-S cross-link bonds to break out, increase the surface porosity of crumb rubber and activate consequently crumb rubber.However, with over long microwave exposure time, the crosslinking density will increase, the regeneration rate of cross-linked structure will accelerate and the modification effect tends to bad.

叶园园(1992-),女,硕士研究生,研究方向为微波活化废轮胎胶粉及其改性沥青的制备,2425639564@qq.com。