Effects of SBS Microstructure on the Properties of SBS Modified Asphalts
The microstructure of SBS affects the properties of SBS modified asphalts.lhe livingness of anionic polymerization can achieve precise control over the microstructure.The structure parameters of SBS in-clude architecture,molecular weight,styrene content,diblock content,vinyl content and functionalization.The molecular weight and its distribution,diblock content,styrene content,and vinyl content can be meas-ured by size exclusion chromatography and nuclear magnetic resonance.SBS with radial architecture or higher molecular weight has better modification effects,but worse compatibility with asphalts.The hot-storage sta-bility and cracking resistance of asphalts modified by SBS with lower styrene content are better,while the workability and high-temperature properties of those with higher styrene content are better.Diblock can im-prove processability and cracking resistance,but damage high-temperature performance.Higher vinyl con-tent can improve compatibility,aging resistance and high-temperature performance,but is detrimental to low-temperature performance.Functionalization can improve the compatibility between SBS and asphalts.SBS modifiers with appropriate microstructures should be selected for specific service conditions.
SBS modified asphaltssize exclusion chromatographydiblockvinyl contentproperty
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