Both macro and micro-methods were introduced to study the physical and chemical properties of thermal oxidative aging of SBS （styrene-butadiene-styrene） modified asphalt. The physical properties of SBS modified asph...Both macro and micro-methods were introduced to study the physical and chemical properties of thermal oxidative aging of SBS （styrene-butadiene-styrene） modified asphalt. The physical properties of SBS modified asphalt before and after aging were analyzed by normal tests. The structure and quality variation of SBS modified asphalt during the aging process was analyzed by FTIR （Fourier transform infrared spectrum）. FTIR result shows that the degeneration of SBS modified asphalt is mainly caused by oxidative reaction and rupture of C=C double bond. The molecular weight variations of asphalt function groups and SBS polymer were studied by GPC （Gel Permeation Chromatography）. GPC result shows that small molecules transform into larger one in asphalt and SBS polymer molecule degrade during the aging process. SBS polymer may lose its modifying function after long time aging.展开更多
This study investigates the long-term thermal-oxidative stability and mechanical properties of phenolcontaining phthalonitrile monomer(PN75)and dicyanate ester of bisphenol-A(DCBA)composites reinforced with short carb...This study investigates the long-term thermal-oxidative stability and mechanical properties of phenolcontaining phthalonitrile monomer(PN75)and dicyanate ester of bisphenol-A(DCBA)composites reinforced with short carbon fibers T700SC(SCF)within a temperature range of 330375℃.The research focuses on the PN75 monomer and DCBA blend reinforced SCF composites with varying SCF content,examining mass loss and changes in flexural strength after thermal aging for 50 h(h).Results show that the SCF-reinforced composites based on the PN75/DCBA blend consistently outperform the neat blend in flexural strength,both at room temperature and after thermal aging.The introduction of the SCF significantly improves the composites'thermal stability and mechanical retention,with higher SCF content correlating to better performance.Notably,after aging at 350℃,the SCF-reinforced composites based(30%(mass)SCF)retained 88.8%of its flexural strength,compared to 61.1%for the neat blend.Morphological analysis reveals that while thermal aging causes degradation of the PN75/DCBA blend layer on SCF surfaces,the overall composite structure maintains good mechanical properties up to 350℃.At 375℃,significant degradation occurs,yet the composites still retain flexural strengths above 78 MPa.This study demonstrates the potential of the SCF-reinforced composites based on PN75/DCBA blend for high-temperature applications,establishing their upper-temperature limit for long-term use in oxidative environments.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.50878054,51108081)
文摘Both macro and micro-methods were introduced to study the physical and chemical properties of thermal oxidative aging of SBS （styrene-butadiene-styrene） modified asphalt. The physical properties of SBS modified asphalt before and after aging were analyzed by normal tests. The structure and quality variation of SBS modified asphalt during the aging process was analyzed by FTIR （Fourier transform infrared spectrum）. FTIR result shows that the degeneration of SBS modified asphalt is mainly caused by oxidative reaction and rupture of C=C double bond. The molecular weight variations of asphalt function groups and SBS polymer were studied by GPC （Gel Permeation Chromatography）. GPC result shows that small molecules transform into larger one in asphalt and SBS polymer molecule degrade during the aging process. SBS polymer may lose its modifying function after long time aging.
基金funded by the Innovative Research Group project of the National Natural Science Foundation of China(52373003).
文摘This study investigates the long-term thermal-oxidative stability and mechanical properties of phenolcontaining phthalonitrile monomer(PN75)and dicyanate ester of bisphenol-A(DCBA)composites reinforced with short carbon fibers T700SC(SCF)within a temperature range of 330375℃.The research focuses on the PN75 monomer and DCBA blend reinforced SCF composites with varying SCF content,examining mass loss and changes in flexural strength after thermal aging for 50 h(h).Results show that the SCF-reinforced composites based on the PN75/DCBA blend consistently outperform the neat blend in flexural strength,both at room temperature and after thermal aging.The introduction of the SCF significantly improves the composites'thermal stability and mechanical retention,with higher SCF content correlating to better performance.Notably,after aging at 350℃,the SCF-reinforced composites based(30%(mass)SCF)retained 88.8%of its flexural strength,compared to 61.1%for the neat blend.Morphological analysis reveals that while thermal aging causes degradation of the PN75/DCBA blend layer on SCF surfaces,the overall composite structure maintains good mechanical properties up to 350℃.At 375℃,significant degradation occurs,yet the composites still retain flexural strengths above 78 MPa.This study demonstrates the potential of the SCF-reinforced composites based on PN75/DCBA blend for high-temperature applications,establishing their upper-temperature limit for long-term use in oxidative environments.
