Microcapsulated chlorocyclophosphazenes were synthesized,and then microcapsulated chlorocyclo- phosphazene/polypropylene(PP)composites were prepared.The results showed that microcapsulated chlorocyclo- phosphazene had...Microcapsulated chlorocyclophosphazenes were synthesized,and then microcapsulated chlorocyclo- phosphazene/polypropylene(PP)composites were prepared.The results showed that microcapsulated chlorocyclo- phosphazene had good high thermal stability through thermogravimetric analysis(TGA).The flammability and mechanical properties of microcapsulated chlorocyclophosphazene/polypropylene composites were investigated by limiting oxygen index experiment,UL 94V flame retardancy test,cone calorimetry,tensile experiment,and impact test,respectively.It was shown that the microcapsulated chlorocyclophosphazene/PP composites had better tensile strength,impact strength,flame retardant properties and smoke suppress properties compared with chlorocyclo- phosphazene/PP composites.展开更多
The Arizona Department of Transportation （ADOT） in the USA conducted a series of asphalt aging related research and special studies between the 1970s and 1990s. The studies covered over 157 test sections representin...The Arizona Department of Transportation （ADOT） in the USA conducted a series of asphalt aging related research and special studies between the 1970s and 1990s. The studies covered over 157 test sections representing both neat （virgin） asphalt and crumb rubber modified （asphalt-rubber） binders. The data comprised of a wide range of penetration, viscosity, and Performance Grade （PG） parameters, at original and aged conditions. In the late 1990s, asphalt PG complex shear modulus （G＊）, and phase angle （5） data were collected. The main purpose of this paper was to use the assembled database of the field core-aged asphalt test data and compare the test results to the American Association of State Highway and Transportation Officials approved Mechanistic-Empirical Pavement Design Guide （MEPDG） predictive modeled asphalt properties such as penetration and viscosity, G＊, and 5. Furthermore, G＊ and laboratory measurements on neat and asphalt-rubber binders extracted from the field cores of the pavement sections aged ten or more years were compared to the pressure aging vessel PG G＊ and ~. values. It was observed that the MEPDG predicted asphalt binder properties were rational for originally （tank） sampled binders, but fairly correlated for the aged binders. Additionally, penetration and viscosity aging indices representing over 20 years of field aged sections were established for a wide variety of asphalt binder grades. Overall, the relationships for aging indices were meaningful and rational. Results of this research indicated the degree of difficulty in predicting asphalt binder properties for pavements with ten or more years of field aging. The findings from this research study are envisioned to be of substantial value in future asphalt binder aging studies.展开更多
基金Supported by the National Natural Science Foundation of China （No.50303005）, the Natural Science Foundation of Shanxi Province （No.20041029） and the Project of Science and Technology of Shanxi Province （No.012078）.
文摘Microcapsulated chlorocyclophosphazenes were synthesized,and then microcapsulated chlorocyclo- phosphazene/polypropylene(PP)composites were prepared.The results showed that microcapsulated chlorocyclo- phosphazene had good high thermal stability through thermogravimetric analysis(TGA).The flammability and mechanical properties of microcapsulated chlorocyclophosphazene/polypropylene composites were investigated by limiting oxygen index experiment,UL 94V flame retardancy test,cone calorimetry,tensile experiment,and impact test,respectively.It was shown that the microcapsulated chlorocyclophosphazene/PP composites had better tensile strength,impact strength,flame retardant properties and smoke suppress properties compared with chlorocyclo- phosphazene/PP composites.
文摘The Arizona Department of Transportation （ADOT） in the USA conducted a series of asphalt aging related research and special studies between the 1970s and 1990s. The studies covered over 157 test sections representing both neat （virgin） asphalt and crumb rubber modified （asphalt-rubber） binders. The data comprised of a wide range of penetration, viscosity, and Performance Grade （PG） parameters, at original and aged conditions. In the late 1990s, asphalt PG complex shear modulus （G＊）, and phase angle （5） data were collected. The main purpose of this paper was to use the assembled database of the field core-aged asphalt test data and compare the test results to the American Association of State Highway and Transportation Officials approved Mechanistic-Empirical Pavement Design Guide （MEPDG） predictive modeled asphalt properties such as penetration and viscosity, G＊, and 5. Furthermore, G＊ and laboratory measurements on neat and asphalt-rubber binders extracted from the field cores of the pavement sections aged ten or more years were compared to the pressure aging vessel PG G＊ and ~. values. It was observed that the MEPDG predicted asphalt binder properties were rational for originally （tank） sampled binders, but fairly correlated for the aged binders. Additionally, penetration and viscosity aging indices representing over 20 years of field aged sections were established for a wide variety of asphalt binder grades. Overall, the relationships for aging indices were meaningful and rational. Results of this research indicated the degree of difficulty in predicting asphalt binder properties for pavements with ten or more years of field aging. The findings from this research study are envisioned to be of substantial value in future asphalt binder aging studies.
