Esterified starch/polylactic acid(ES/PLA) blending composite was prepared by melting extrusion with maleic anhydride esterified starch and PLA as the raw materials. The composite was accelerated aging by using UV ag...Esterified starch/polylactic acid(ES/PLA) blending composite was prepared by melting extrusion with maleic anhydride esterified starch and PLA as the raw materials. The composite was accelerated aging by using UV aging box, and its properties were characterized by Fourier transform infrared spectroscopy(FT-IR), scanning electron microscopy(SEM), X-ray diffraction(XRD), thermo gravimetric analysis(TGA) and mechanical testing machine. FT-IR and SEM results show that the infrared absorption peak intensities of C-O, C-H, and C=O in aged samples decrease gradually with increasing aging time. The damage degree of surface and internal of aged samples increases gradually. XRD analysis results show that after aging treatment, the crystalline diffraction peak of thermoplastic esterified starch at 2θ = 21° disappears and the diffraction peaks of PLA at 2θ = 16.5° appear, indicating that the hydrolysis rate of esterified starch is greater than that of PLA. The crystallinity of PLA in aged sample shows an increasing trend at first followed by a decreasing one along with the increasing time of aging treatment, suggesting that the hydrolysis of amorphous regions of PLA is more preferential than its crystalline regions. Because of the influence of crystal structure and the change of composition structure, the initial decomposition temperature of aging test specimen gradually increases with the extension of aging time. The maximum decomposition rate temperature and residual mass increases at first, and then decrease after the aging time extending to 1600 h. As the aging time increases, the damage degree of combination interface between esterification starch and PLA is exacerbated, resulting in the tensile strength and bending strength of aged specimen decreasing gradually.展开更多
We applied LDHs to modify the bitumen by melt blending, and studied the viscoelasticity of LDHs modifi ed bitumen by means of dynamic shear rheometer(DSR). The creep test was used to evaluate the viscoelastic behavi...We applied LDHs to modify the bitumen by melt blending, and studied the viscoelasticity of LDHs modifi ed bitumen by means of dynamic shear rheometer(DSR). The creep test was used to evaluate the viscoelastic behavior. The experimental results indicated that, due to the addition of the LDHs, the viscoelastic properties of modifi ed bitumen were superior to those of pristine bitumen. Therefore, the LDHs would be an alternative to modifi ers used in the bitumen to improve the UV-aging resistance during the service of asphalt pavement.展开更多
Effects of organosilicon coating with light stabilizer UV326,UV531 and 770 on ultraviolet (UV) aging resistance of bitumen were investigated by testing the viscosity,softening point and the changes of chemical compone...Effects of organosilicon coating with light stabilizer UV326,UV531 and 770 on ultraviolet (UV) aging resistance of bitumen were investigated by testing the viscosity,softening point and the changes of chemical component before and after UV aging. The results show that UV aging resistance of bitumen is improved due to the good weatherability of organosilicon. And the UV aging resistance of bitumen is further enhanced by adding light stabilizer into organosilicon coating due to the good UV absorption of light stabilizers. Bitumen coated with organosilicon coating containing UV326 exhibits better UV aging resistance in comparison with bitumen coated with organosilicon containing UV531 or 770.展开更多
Layered double hydroxides (LDHs)/styrene-butadiene-styrene (SBS) eopolymer modified bitumen was prepared by melt blending. The effect of LDHs on the ultraviolet (UV) aging behavior of SBS modified bitumen was in...Layered double hydroxides (LDHs)/styrene-butadiene-styrene (SBS) eopolymer modified bitumen was prepared by melt blending. The effect of LDHs on the ultraviolet (UV) aging behavior of SBS modified bitumen was investigated. The changes of chemical structures of modified bitumen before and after UV aging were characterized by Fourier transform infrared spectroscopy (FTIR). The results show that LDHs obviously reduce the variation of softening point and low temperature flexibility of SBS modified bitumen under different UV radiation intensities, which indicates that the UV aging resistance performance of SBS modified bitumen is improved effectively by LDHs. Compared with SBS modified bitumen, the changes of carbonyl, sulfoxide and butadienyl of LDHs/SBS modified bitumen decrease significantly after UV aging according to FTIR analysis, demonstrating that the oxidation and degradation reactions of SBS modified bitumen were restrained effectively by adding LDHs.展开更多
Dynamic rheological properties of asphalt modified by Supramolecular UV resistant material—layered double hydroxides(LDHs) was studied by means of the dynamic shear rheometer(DSR) test.Two typical base asphalts w...Dynamic rheological properties of asphalt modified by Supramolecular UV resistant material—layered double hydroxides(LDHs) was studied by means of the dynamic shear rheometer(DSR) test.Two typical base asphalts were chosen and modified by 2 different LDHs contents.DSR tests were performed on the original samples,samples after exposed to outdoor and samples after the artificial accelerated UV aging tests respectively to analyze the rheological properties.It is found that when the LDHs content is between 3wt% and 5wt% of asphalt weight,the high temperature performance and fatigue resistant property of the modified asphalt become better,the UV aging resistance properties are improved.展开更多
LDHs was introduced into 70# asphalt binder by different weight ratio. Asphalt penetration test, soft point test, ductility test, viscosity test, dynamic shear rheometer(DSR) test and Fourier transform infrared(FTI...LDHs was introduced into 70# asphalt binder by different weight ratio. Asphalt penetration test, soft point test, ductility test, viscosity test, dynamic shear rheometer(DSR) test and Fourier transform infrared(FTIR) test, were conducted to characterize and predict the LDHs modified asphalt. Research results indicated that the LDHs has great effect on resistance to UV of asphalt, which makes the asphalt absorb less ultraviolet radiation under the same UV intensity. Complex modulus, phase angle and FTIR test results indicate that the LDHs can significantly enhance the property of anti-ultraviolet aging of asphalt. The test results show that the LDHs has an obvious improvement on the anti UV aging of asphalt.展开更多
A completely green pathway for the preparation of Ag nanoparticles was proposed, by using soy protein isolate (SPI) as stabilizer under UV irradiation and H2O as the environmentally benign solvent throughout the pre...A completely green pathway for the preparation of Ag nanoparticles was proposed, by using soy protein isolate (SPI) as stabilizer under UV irradiation and H2O as the environmentally benign solvent throughout the preparation. Transmission electronic microscopy (TEM) and zeta potential characterization results indicated that the Ag nanoparticles were stable and well dispersed with an average diameter about 13 nm, and X-ray diffraction (XRD) analysis of SPI/Ag composite nanoparticles confirmed the formation of metallic silver. UV-Vis spectrum showed that the Ag nanoparticles dispersion solution had the maximum absorbance at about 430 nm due to surface plasmon resonance of the Ag nanoparticles. Infrared spectroscopy confirmed that the polypeptide backbone of SPI was not cleaved during the conjugation process and that some active amino groups were oxidized. The SPI/Ag composite nanoparticles have excellent antibacterial activity against two representative bacteria, staphylococcus aureus (Gram positive) and escherichia coli (Gram negative) in the presence of SPI.展开更多
Asphalt binder is inevitably aged by ultraviolet(UV)light during its service period.UV ageing can significantly decrease the technical properties of asphalt binder.The sensitivity of asphalt to UV ageing and thermal-o...Asphalt binder is inevitably aged by ultraviolet(UV)light during its service period.UV ageing can significantly decrease the technical properties of asphalt binder.The sensitivity of asphalt to UV ageing and thermal-oxidative ageing differs,such that the UV ageing performance cannot be determined based on the thermal-oxidative ageing performance.Previous researches mainly focused on the chemical composite and technical performance changes of asphalt binder during UV ageing,and the UV light parameters effect on the ageing rate of asphalt binder.However,the theory for characterizing and explaining the development of UV ageing depth does not get too much attentions,and the UV ageing mechanism of asphalt binder is not very clear.Therefore,it cannot guide to develop or select the good methods or anti-UV ageing additives for asphalt binders.This paper focuses on the latest researches of the mechanisms and anti-ageing methods of asphalt binders.With the increase of UV ageing time,the UV ageing of asphalt binder develops gradually from the surface to inner part.There are various methods,such as low-penetration grade asphalt,less air void ratio,UV stabilizers and UV light absorbers,that can improve the UV ageing resistance of asphalt binders.A new theory of sensitive wavelengths of asphalt UV ageing is proposed,which can enrich the basic theory of asphalt UV ageing.Depending on this theory,different wavelengths of UV light have different ageing effects on asphalt binder.The composite anti-UV ageing additives with barrier and specific absorption effects on UV light is proposed,and may have better improvement effect on the anti-UV ageing performance of asphalt binder.展开更多
基金Funded by the Key Laboratory of Bio-based Material Science&Technology(Northeast Forestry University)Ministry of Education(SWZCL2016-04)+1 种基金the Scientific Research Project of Hunan Provincial Education Department(15C1428)the State Bureau of Forestry 948 Project(2009-4-51)
文摘Esterified starch/polylactic acid(ES/PLA) blending composite was prepared by melting extrusion with maleic anhydride esterified starch and PLA as the raw materials. The composite was accelerated aging by using UV aging box, and its properties were characterized by Fourier transform infrared spectroscopy(FT-IR), scanning electron microscopy(SEM), X-ray diffraction(XRD), thermo gravimetric analysis(TGA) and mechanical testing machine. FT-IR and SEM results show that the infrared absorption peak intensities of C-O, C-H, and C=O in aged samples decrease gradually with increasing aging time. The damage degree of surface and internal of aged samples increases gradually. XRD analysis results show that after aging treatment, the crystalline diffraction peak of thermoplastic esterified starch at 2θ = 21° disappears and the diffraction peaks of PLA at 2θ = 16.5° appear, indicating that the hydrolysis rate of esterified starch is greater than that of PLA. The crystallinity of PLA in aged sample shows an increasing trend at first followed by a decreasing one along with the increasing time of aging treatment, suggesting that the hydrolysis of amorphous regions of PLA is more preferential than its crystalline regions. Because of the influence of crystal structure and the change of composition structure, the initial decomposition temperature of aging test specimen gradually increases with the extension of aging time. The maximum decomposition rate temperature and residual mass increases at first, and then decrease after the aging time extending to 1600 h. As the aging time increases, the damage degree of combination interface between esterification starch and PLA is exacerbated, resulting in the tensile strength and bending strength of aged specimen decreasing gradually.
基金Funded by the Key Scientific Apparatus Development Program from the Ministry of Science and Technology of China(No.2013YQ160501)the National Basic Research Program of China(No.2014CB932104)+1 种基金the Natural Science Foundation of China(No.51278392)the Science and Technology Plan Projects of the Ministry of Transport of China(No.2013318811250)
文摘We applied LDHs to modify the bitumen by melt blending, and studied the viscoelasticity of LDHs modifi ed bitumen by means of dynamic shear rheometer(DSR). The creep test was used to evaluate the viscoelastic behavior. The experimental results indicated that, due to the addition of the LDHs, the viscoelastic properties of modifi ed bitumen were superior to those of pristine bitumen. Therefore, the LDHs would be an alternative to modifi ers used in the bitumen to improve the UV-aging resistance during the service of asphalt pavement.
基金a research project 51078300 supported by National Natural Science Foundation of chinasupported by self-determined and innovative research funds of WUT(2010-YB-04)
文摘Effects of organosilicon coating with light stabilizer UV326,UV531 and 770 on ultraviolet (UV) aging resistance of bitumen were investigated by testing the viscosity,softening point and the changes of chemical component before and after UV aging. The results show that UV aging resistance of bitumen is improved due to the good weatherability of organosilicon. And the UV aging resistance of bitumen is further enhanced by adding light stabilizer into organosilicon coating due to the good UV absorption of light stabilizers. Bitumen coated with organosilicon coating containing UV326 exhibits better UV aging resistance in comparison with bitumen coated with organosilicon containing UV531 or 770.
基金Funded by the National Basic Research Program of China(973 Program)(No.2014CB932104)
文摘Layered double hydroxides (LDHs)/styrene-butadiene-styrene (SBS) eopolymer modified bitumen was prepared by melt blending. The effect of LDHs on the ultraviolet (UV) aging behavior of SBS modified bitumen was investigated. The changes of chemical structures of modified bitumen before and after UV aging were characterized by Fourier transform infrared spectroscopy (FTIR). The results show that LDHs obviously reduce the variation of softening point and low temperature flexibility of SBS modified bitumen under different UV radiation intensities, which indicates that the UV aging resistance performance of SBS modified bitumen is improved effectively by LDHs. Compared with SBS modified bitumen, the changes of carbonyl, sulfoxide and butadienyl of LDHs/SBS modified bitumen decrease significantly after UV aging according to FTIR analysis, demonstrating that the oxidation and degradation reactions of SBS modified bitumen were restrained effectively by adding LDHs.
文摘Dynamic rheological properties of asphalt modified by Supramolecular UV resistant material—layered double hydroxides(LDHs) was studied by means of the dynamic shear rheometer(DSR) test.Two typical base asphalts were chosen and modified by 2 different LDHs contents.DSR tests were performed on the original samples,samples after exposed to outdoor and samples after the artificial accelerated UV aging tests respectively to analyze the rheological properties.It is found that when the LDHs content is between 3wt% and 5wt% of asphalt weight,the high temperature performance and fatigue resistant property of the modified asphalt become better,the UV aging resistance properties are improved.
基金supported by the National Natural Science Foundation of China (No. 51778515)Ministry of Science and Technology National Key R&D Plan (No. 2017YFE0111600)
文摘LDHs was introduced into 70# asphalt binder by different weight ratio. Asphalt penetration test, soft point test, ductility test, viscosity test, dynamic shear rheometer(DSR) test and Fourier transform infrared(FTIR) test, were conducted to characterize and predict the LDHs modified asphalt. Research results indicated that the LDHs has great effect on resistance to UV of asphalt, which makes the asphalt absorb less ultraviolet radiation under the same UV intensity. Complex modulus, phase angle and FTIR test results indicate that the LDHs can significantly enhance the property of anti-ultraviolet aging of asphalt. The test results show that the LDHs has an obvious improvement on the anti UV aging of asphalt.
基金the National Natural Science Foundation of China(Nos.50673038 and 20374025)the Fundamental Research Funds for the Central Universities of China(No.JUSRP111A08)
文摘A completely green pathway for the preparation of Ag nanoparticles was proposed, by using soy protein isolate (SPI) as stabilizer under UV irradiation and H2O as the environmentally benign solvent throughout the preparation. Transmission electronic microscopy (TEM) and zeta potential characterization results indicated that the Ag nanoparticles were stable and well dispersed with an average diameter about 13 nm, and X-ray diffraction (XRD) analysis of SPI/Ag composite nanoparticles confirmed the formation of metallic silver. UV-Vis spectrum showed that the Ag nanoparticles dispersion solution had the maximum absorbance at about 430 nm due to surface plasmon resonance of the Ag nanoparticles. Infrared spectroscopy confirmed that the polypeptide backbone of SPI was not cleaved during the conjugation process and that some active amino groups were oxidized. The SPI/Ag composite nanoparticles have excellent antibacterial activity against two representative bacteria, staphylococcus aureus (Gram positive) and escherichia coli (Gram negative) in the presence of SPI.
基金The authors acknowledge the financial supported by National Natural Science Foundation of China(No.52108415 and No.51808517)the National Key R&D Program of China(No.2018YFB1600200)+5 种基金the Key Technical Innovation Projects of Hubei Province(No.2019AEE023)the Key R&D Program of Hubei Province(No.2020BCB064)the State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(No.SYSJJ2022-21),the Transportation Technology Project of Department of Transport of Hubei Province(No.2022-11-1-10)the European Union's Horizon 2020 Research and Innovation Programme Under the Marie Skłodowska-Curie Grant Agreement(No.101030767)the Scientific Research Fund Project of Wuhan Institute of Technology(No.K2021032)the Open Fund of National&Local Joint Engineering Laboratory of Traffic Civil Engineering Materials,Chongqing Jiaotong University(No.LHSYS-2020-004).
文摘Asphalt binder is inevitably aged by ultraviolet(UV)light during its service period.UV ageing can significantly decrease the technical properties of asphalt binder.The sensitivity of asphalt to UV ageing and thermal-oxidative ageing differs,such that the UV ageing performance cannot be determined based on the thermal-oxidative ageing performance.Previous researches mainly focused on the chemical composite and technical performance changes of asphalt binder during UV ageing,and the UV light parameters effect on the ageing rate of asphalt binder.However,the theory for characterizing and explaining the development of UV ageing depth does not get too much attentions,and the UV ageing mechanism of asphalt binder is not very clear.Therefore,it cannot guide to develop or select the good methods or anti-UV ageing additives for asphalt binders.This paper focuses on the latest researches of the mechanisms and anti-ageing methods of asphalt binders.With the increase of UV ageing time,the UV ageing of asphalt binder develops gradually from the surface to inner part.There are various methods,such as low-penetration grade asphalt,less air void ratio,UV stabilizers and UV light absorbers,that can improve the UV ageing resistance of asphalt binders.A new theory of sensitive wavelengths of asphalt UV ageing is proposed,which can enrich the basic theory of asphalt UV ageing.Depending on this theory,different wavelengths of UV light have different ageing effects on asphalt binder.The composite anti-UV ageing additives with barrier and specific absorption effects on UV light is proposed,and may have better improvement effect on the anti-UV ageing performance of asphalt binder.