聚氨酯固-固相变材料改性沥青的流变性能与改性机理

Rheological Properties and Modified Mechanism of Polyurethane Solid-solid Phase Change Materials Modified Asphalt

为评价聚氨酯固-固相变材料(PUSSPCMs)作为沥青改性剂的潜力,确定PUSSPCMs对沥青流变性能的影响及作用机理,以不同质量分数的软段制备了PUSSPCMs(P70、P75、P80、P85和P90)及PUSSPCMs改性沥青,采用沥青调温性能、动态剪切流变(DSR)以及弯曲梁流变(BBR)试验测试了热性能和流变性能,并借助差示扫描量热(DSC)、红外光谱(FTIR)和原子力显微镜(AFM)分析了改性机理。结果表明:PUSSPCMs改性沥青较基质沥青的调温性能、抗变形和高温性能提高,低温性能降低;PUSSPCMs软段质量分数增加,PUSSPCMs改性沥青的调温性能和低温性能明显提高,抗变形和高温性能降低,其中P90沥青具有最好的调温性能和低温性能,而P70沥青的抗变形和高温性能最好;PUSSPCMs的储能放热性能优良,P90焓值较高而P70相变起始温度较低,焓值与PUSSPCMs改性沥青的调温性能高度相关。PUSSPCMs与沥青之间未产生新的官能团,为物理改性;PUSSPCMs对沥青微观形貌影响显著,弹性模量增大,但随着软段质量分数增加,沥青“蜂状结构”增多而周边相态差异降低,弹性模量减小,这与PUSSPCMs改性沥青高低温性能的转变关联紧密。

To evaluate the potential of polyurethane solid-solid phase change materials(PUSSPCMs)as asphalt modifiers,the influence of PUSSPCMs soft segments on the rheological properties and mechanism of asphalt was investigated.Therefore,PUSSPCMs with different soft-segment mass fractions(P70,P75,P80,P85,and P90)and the corresponding PUSSPCMs modified asphalt were prepared as testing materials in this study.Temperature regulating properties,dynamic shear rheology(DSR),and bending beam rheology(BBR)tests were used to investigate the temperature regulation and rheological properties of PUSSPCMs modified asphalt,and the modified mechanism was analyzed by differential scanning calorimetry(DSC),Fourier transform infrared(FTIR),and atomic force microscopy(AFM).The results show that PUSSPCMs modified asphalt exhibits better temperature-regulating properties than base asphalt,as well as greater deformation resistance and high-temperature performance,while low-temperature performance is lower.The temperature regulating properties and low-temperature performance of PUSSPCMs modified asphalt are greatly enhanced as the soft segment mass fraction increases,while the deformation resistance and high-temperature performance are correspondingly reduced.P90 asphalt has the best temperature-regulating properties and low-temperature performance,whereas P70 asphalt has the highest deformation resistance and high-temperature performance.PUSSPCMs have excellent heat storage-release properties,and P90 has a greater enthalpy and a lower initial temperature than P70.Furthermore,the enthalpy of PUSSPCMs is closely linked to the temperature-regulating properties of PUSSPCMs modified asphalt.In addition,there is no new functional group between the PUSSPCMs and asphalt,which means that it is a physical modification.As the soft segment mass fraction of PUSSPCMs increases,the“bee-like structure”of the asphalt expands,while the difference between the peripheral phase state and Young’s modulus decreases.These are inextricably related to the high-and low-temperature performances of PUSSPCMs modified asphalt.