Preparation and performance evaluation of low-melting polypropylene-based asphalt modifier
The use of waste polypropylene(PP)in bitumen modification is a technical bottleneck because its melting temperature is far higher than the conventional blending temperature of asphalt.This study adopted different dosages of dicumyl peroxide(DCP)to pretreat waste PP for preparing different low-melting asphalt modifiers through a mechanochemical degradation method,and the modified asphalts were prepared using a melt-mixing method,which the mass ratios of DCP to waste PP were 0.0%,0.1%,0.3%,and 0.5%,respectively.Using the differential scanning calorimeter test,the effect of DCP dosages on the thermal stability of waste PP was studied,and the effects of different PP modifiers on the molecular structure,microscopic morphology and rheological properties of bitumen were also evaluated using the Fourier transform infrared spectroscopy,fluorescence microscopy,and dynamic shear rheology tests.The results show that DCP reduces the thermal stability of waste PP,and the degradation degree of waste PP reaches a maximum level as the mass ratio of DCP to waste PP is 0.3%;the modification processes of PP modifiers to bitumen physical interaction;the compatibility between waste PP and bitumen can be further improved;and the degradation impact of DCP on waste PP does not significantly affect the deformation resistance of asphalt binder,and the rheological properties of their modified asphalts are close to each other when the mass ratios of DCP to waste PP are 0.0%and 0.3%,respectively.
万方数据
维普
