γ辐照对回收LDPE改性沥青蠕变恢复特性的影响

Effect of Gamma-Irradiation on Creep and Recovery Properties of Recycled Low-density Polyethylene Modified Asphalt

为提高回收低密度聚乙烯(LDPE_R)改性沥青的性能,采用伽马射线(γ)辐照处置的回收低密度聚乙烯聚合物制备相应的改性沥青。通过表面形态、FTIR光谱研究了其中的化学改性机理,采用多应力蠕变恢复试验(MSCR)研究了γ-LDPE_R改性沥青高温蠕变恢复特性。结果表明,γ-LDPE_R对沥青的加劲效果增强了沥青的温度稳定性,且采用γ-LDPE_R聚合物改性具有更好的高温性能。当LDPE_R表面采用伽马射线辐照后形成自由基和一些官能团,使聚合物改性剂和沥青之间形成较强的化学键,从而提高了改性沥青的相容性。随着γ-LDPE_R用量增加,改性沥青高温稳定性增加,然而对于高掺量γ-LDPE_R的改性沥青,采用MSCR评价高温性能的适用性值得进一步研究。

In order to improve the performance of recycled low-density polyethylene（LDPER）,the modified asphalt with gamma-irradiated recycled low-density polyethylene（γ-LDPER） is prepared. The chemical modification effect of γ-LDPER on asphalt is investigated by means of morphology and FTIR spectroscopy,and the high temperature creep-recovery property of γ-LDPERmodified asphalt is studied by multiple stress creep recovery test. The result shows that（1） the stiffening effect of γ-LDPERincreased the temperature stability of base asphalt and γ-LDPERmodified asphalt has better high temperature performance;（2） the surface of the LDPERwhich treated by gamma beam irradiation provided formation of free radicals and some functional groups that may contribute to the creation of strong chemical bonds between polymer modifier and asphalt and improved the compatibility of the modified asphalt. With the increased use of γ-LDPER,the high temperature stability of the modified asphalt increased,but for the modified asphalt with high content of γ-LDPER,using MSCR to evaluate the applicability of the high temperature performance deserves further study.