The mechanical properties and dynamic mechanical properties of blends composed of Nylon 6 and poly （ butylenes terephthalate） （PBT）, with styrene/maleic anhydride（SMA） as compatibilizer, were studied. The observ...The mechanical properties and dynamic mechanical properties of blends composed of Nylon 6 and poly （ butylenes terephthalate） （PBT）, with styrene/maleic anhydride（SMA） as compatibilizer, were studied. The observation on the morphologies of the etched surfaces of the cryogenically fractured specimens via scanning electron microscopy（SEM） demonstrated that in the compatibilized Nylon 6/PBT blends, there exists a finer and more uniform dispersion induced by the in-situ interfacial chemical reactions during the preparation than that in the corresponding uncompatibilized blends. On the other hand, the overall mechanical properties of the compatibilized blends could be remarkably im- proved compared with those of the uncompatibilized ones. Moreover, increasing the amount of the compatibilizer SMA leads to a more efficient dispersion of the PBT phase in Nylon 6/PBT blends. Furthermore, there exists an optimum level of SMA added to achieve the maximum mechanical properties. As far as the mechanism of this reactive compatibilization is concerned, the enhanced interfacial adhesion is necessary to obtain improved dispersion, stable phase morphology, and better mechanical properties.展开更多
Cord fabric is a critical material used in the manufacture of tyres and various composite materials to increase durability and strength. The tyre consists of many layers of cord fabric, with each layer being referred ...Cord fabric is a critical material used in the manufacture of tyres and various composite materials to increase durability and strength. The tyre consists of many layers of cord fabric, with each layer being referred to as a cord ply. These layers are strategically positioned within the tyre’s internal structure, particularly in the tread and sidewall areas, to improve handling, durability and impact resistance. The cord fabric also serves a critical role in maintaining the structural integrity of the tyre, ensuring that it retains its contour and resists deformations under different operating conditions. This study discusses the advantages and disadvantages of using Nylon 6 (NY6) and Nylon 66 (NY66) cord fabrics in scooter tire production, with a focus on their mechanical behavior under varying curing temperatures and pressures. It was observed that while the curing time for both NY6 and NY66 remained consistent across different platen temperatures and pressures, their mechanical properties showed significant differences. NY6, known for its flexibility and impact resistance, exhibited greater changes in cord-breaking strength and elongation with increasing temperature, showing a marked decrease in breaking strength at higher temperatures. In contrast, NY66 maintained better stability and performance under similar conditions.展开更多
The preparation process-dependent phase morphology of blends composed of nylon 6 and acrylonitrile-butadiene- styrene(ABS)over a composition range of 30-70 wt% using a styrene-maleic anhydride(SMA)copolymer as the com...The preparation process-dependent phase morphology of blends composed of nylon 6 and acrylonitrile-butadiene- styrene(ABS)over a composition range of 30-70 wt% using a styrene-maleic anhydride(SMA)copolymer as the compatibilizing agent with a constant content(5phr)was investigated.The results of the scanning electron microscope (SEM)observation revealed that compared with the binary blends of nylon 6 and ABS,the existence of SMA caused a composition shift of phase inversion to a higher weight fraction of ny...展开更多
Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte reaction.However,their moderate unit-cellvolume expansion(gen...Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte reaction.However,their moderate unit-cellvolume expansion(generally 5%–10%)during Li^(+)storage causes unsatisfactory long-term cyclability.Here,“zero-strain”NiNb_(2)O_(6) fibers are explored as a new anode material with comprehensively good electrochemical properties.During Li^(+)storage,the expansion of electrochemical inactive NiO_(6) octahedra almost fully offsets the shrinkage of active NbO_(6) octahedra through reversible O movement.Such superior volume-accommodation capability of the NiO_(6) layers guarantees the“zero-strain”behavior of NiNb_(2)O_(6) in a broad temperature range(0.53%//0.51%//0.74%at 25//−10//60℃),leading to the excellent cyclability of the NiNb_(2)O_(6) fibers(92.8%//99.2%//91.1%capacity retention after 1000//2000//1000 cycles at 10C and 25//−10//60℃).This NiNb_(2)O_(6) material further exhibits a large reversible capacity(300//184//318 mAh g−1 at 0.1C and 25//−10//60℃)and outstanding rate performance(10 to 0.5C capacity percentage of 64.3%//50.0%//65.4%at 25//−10//60℃).Therefore,the NiNb_(2)O_(6) fibers are especially suitable for large-capacity,fast-charging,long-life,and all-climate lithium-ion batteries.展开更多
尼龙6(PA6)树脂具有优异的性能,其连续纤维复合材料在汽车、航空航天领域具有广泛应用。但是PA6树脂熔融后黏度较高,不易对连续纤维充分浸渍,并且连续纤维与PA6的复合材料界面黏附性较差,限制了其复合材料的性能和应用。针对这些问题,...尼龙6(PA6)树脂具有优异的性能,其连续纤维复合材料在汽车、航空航天领域具有广泛应用。但是PA6树脂熔融后黏度较高,不易对连续纤维充分浸渍,并且连续纤维与PA6的复合材料界面黏附性较差,限制了其复合材料的性能和应用。针对这些问题,文中对连续玻璃纤维增强尼龙6(CGF/PA6)复合材料开展了研究。首先,采用阴离子开环聚合制备PA6,确定了其最佳制备工艺;其次,用硅烷偶联剂KH550(AP)对连续玻璃纤维(CGF)进行改性,并对其进行了红外光谱表征;最后,通过原位聚合法制备了CGF/PA6复合材料,研究了AP改性对CGF/PA6复合材料力学性能的影响,并对CGF/PA6复合材料的拉伸断口进行了扫描电镜分析。结果表明,AP被键合到了CGF表面,AP改性可以增强CGF/PA6复合材料的界面黏附性,从而使CGF/PA6复合材料的拉伸强度得到改善,当AP用量为2%时,CGF/PA6复合材料的拉伸强度高达88.52 MPa,此时,复合材料的断裂伸长率最低,为4.90%。CGF/PA6复合材料的冲击强度变化不大,均在50 k J/m2左右,说明复合材料的韧性受CGF表面改性影响较小。展开更多
An experimental research was made to have a grasp of the overall thermo-mechanicalproperties of nylon 6 and nylon 66 tire cords. The strength, fatigue, thermal shrinkage, therm-al aging and dynamic-mechanical properti...An experimental research was made to have a grasp of the overall thermo-mechanicalproperties of nylon 6 and nylon 66 tire cords. The strength, fatigue, thermal shrinkage, therm-al aging and dynamic-mechanical properties of both were measured, investigated and corn-pared. So far as their comprehensive performance is concerned, and favoritism to nylon 66cord for tire cord fabrics is perhaps unwarranted. And the effect of twist on the tensile proper-ties and fatigue behavior also have been measured and analyzed.展开更多
Many researchers have shown interest in the reinforcement of commodity thermoplastic with natural fibers. However, the drawback of natural fibers is their low thermal processing temperatures, that border around 200℃....Many researchers have shown interest in the reinforcement of commodity thermoplastic with natural fibers. However, the drawback of natural fibers is their low thermal processing temperatures, that border around 200℃. In this investigation, we tried to improve the thermal stability of natural fibers with the use of flexible epoxy surface coating that could facilitate processing with engineering thermoplastics. Jute fabric and Polyamide 6 (PA6) composites were prepared by compression molding. The thermal decomposition characteristics of the jute fabric were evaluated by using thermo gravimetric analysis (TGA). Mechanical analysis was conducted to evaluate tensile test and three point bending test of composite. It was found that thermal degradation resistance of jute fabric was improved by coating with flexible epoxy resin. Moreover, the flexural modulus improved with increasing curative concentration. The interfacial interaction between the epoxy and PA6 was clearly indicated by the photo micrographs of the polished cross sections of the coated and uncoated jute fabric/PA6 composites.展开更多
基金Supported by the Natural Science Funds of Guizhou Province,China(No.GY-2005-3036)the National Basic Research Pro-gram of China(No.2005CB623802).
文摘The mechanical properties and dynamic mechanical properties of blends composed of Nylon 6 and poly （ butylenes terephthalate） （PBT）, with styrene/maleic anhydride（SMA） as compatibilizer, were studied. The observation on the morphologies of the etched surfaces of the cryogenically fractured specimens via scanning electron microscopy（SEM） demonstrated that in the compatibilized Nylon 6/PBT blends, there exists a finer and more uniform dispersion induced by the in-situ interfacial chemical reactions during the preparation than that in the corresponding uncompatibilized blends. On the other hand, the overall mechanical properties of the compatibilized blends could be remarkably im- proved compared with those of the uncompatibilized ones. Moreover, increasing the amount of the compatibilizer SMA leads to a more efficient dispersion of the PBT phase in Nylon 6/PBT blends. Furthermore, there exists an optimum level of SMA added to achieve the maximum mechanical properties. As far as the mechanism of this reactive compatibilization is concerned, the enhanced interfacial adhesion is necessary to obtain improved dispersion, stable phase morphology, and better mechanical properties.
文摘Cord fabric is a critical material used in the manufacture of tyres and various composite materials to increase durability and strength. The tyre consists of many layers of cord fabric, with each layer being referred to as a cord ply. These layers are strategically positioned within the tyre’s internal structure, particularly in the tread and sidewall areas, to improve handling, durability and impact resistance. The cord fabric also serves a critical role in maintaining the structural integrity of the tyre, ensuring that it retains its contour and resists deformations under different operating conditions. This study discusses the advantages and disadvantages of using Nylon 6 (NY6) and Nylon 66 (NY66) cord fabrics in scooter tire production, with a focus on their mechanical behavior under varying curing temperatures and pressures. It was observed that while the curing time for both NY6 and NY66 remained consistent across different platen temperatures and pressures, their mechanical properties showed significant differences. NY6, known for its flexibility and impact resistance, exhibited greater changes in cord-breaking strength and elongation with increasing temperature, showing a marked decrease in breaking strength at higher temperatures. In contrast, NY66 maintained better stability and performance under similar conditions.
基金This work was supported by the National Science Funds for GuiZhou Province Science Projects(No.GY-2005-3036)the Special Funds for Major State Basic Research Projects(No.2005CB623802).
文摘The preparation process-dependent phase morphology of blends composed of nylon 6 and acrylonitrile-butadiene- styrene(ABS)over a composition range of 30-70 wt% using a styrene-maleic anhydride(SMA)copolymer as the compatibilizing agent with a constant content(5phr)was investigated.The results of the scanning electron microscope (SEM)observation revealed that compared with the binary blends of nylon 6 and ABS,the existence of SMA caused a composition shift of phase inversion to a higher weight fraction of ny...
基金supported by the National Natural Science Foundation of China(51762014,52231007,12327804,T2321003,22088101)in part by the National Key Research Program of China under Grant 2021YFA1200600.
文摘Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte reaction.However,their moderate unit-cellvolume expansion(generally 5%–10%)during Li^(+)storage causes unsatisfactory long-term cyclability.Here,“zero-strain”NiNb_(2)O_(6) fibers are explored as a new anode material with comprehensively good electrochemical properties.During Li^(+)storage,the expansion of electrochemical inactive NiO_(6) octahedra almost fully offsets the shrinkage of active NbO_(6) octahedra through reversible O movement.Such superior volume-accommodation capability of the NiO_(6) layers guarantees the“zero-strain”behavior of NiNb_(2)O_(6) in a broad temperature range(0.53%//0.51%//0.74%at 25//−10//60℃),leading to the excellent cyclability of the NiNb_(2)O_(6) fibers(92.8%//99.2%//91.1%capacity retention after 1000//2000//1000 cycles at 10C and 25//−10//60℃).This NiNb_(2)O_(6) material further exhibits a large reversible capacity(300//184//318 mAh g−1 at 0.1C and 25//−10//60℃)and outstanding rate performance(10 to 0.5C capacity percentage of 64.3%//50.0%//65.4%at 25//−10//60℃).Therefore,the NiNb_(2)O_(6) fibers are especially suitable for large-capacity,fast-charging,long-life,and all-climate lithium-ion batteries.
文摘尼龙6(PA6)树脂具有优异的性能,其连续纤维复合材料在汽车、航空航天领域具有广泛应用。但是PA6树脂熔融后黏度较高,不易对连续纤维充分浸渍,并且连续纤维与PA6的复合材料界面黏附性较差,限制了其复合材料的性能和应用。针对这些问题,文中对连续玻璃纤维增强尼龙6(CGF/PA6)复合材料开展了研究。首先,采用阴离子开环聚合制备PA6,确定了其最佳制备工艺;其次,用硅烷偶联剂KH550(AP)对连续玻璃纤维(CGF)进行改性,并对其进行了红外光谱表征;最后,通过原位聚合法制备了CGF/PA6复合材料,研究了AP改性对CGF/PA6复合材料力学性能的影响,并对CGF/PA6复合材料的拉伸断口进行了扫描电镜分析。结果表明,AP被键合到了CGF表面,AP改性可以增强CGF/PA6复合材料的界面黏附性,从而使CGF/PA6复合材料的拉伸强度得到改善,当AP用量为2%时,CGF/PA6复合材料的拉伸强度高达88.52 MPa,此时,复合材料的断裂伸长率最低,为4.90%。CGF/PA6复合材料的冲击强度变化不大,均在50 k J/m2左右,说明复合材料的韧性受CGF表面改性影响较小。
文摘An experimental research was made to have a grasp of the overall thermo-mechanicalproperties of nylon 6 and nylon 66 tire cords. The strength, fatigue, thermal shrinkage, therm-al aging and dynamic-mechanical properties of both were measured, investigated and corn-pared. So far as their comprehensive performance is concerned, and favoritism to nylon 66cord for tire cord fabrics is perhaps unwarranted. And the effect of twist on the tensile proper-ties and fatigue behavior also have been measured and analyzed.
文摘Many researchers have shown interest in the reinforcement of commodity thermoplastic with natural fibers. However, the drawback of natural fibers is their low thermal processing temperatures, that border around 200℃. In this investigation, we tried to improve the thermal stability of natural fibers with the use of flexible epoxy surface coating that could facilitate processing with engineering thermoplastics. Jute fabric and Polyamide 6 (PA6) composites were prepared by compression molding. The thermal decomposition characteristics of the jute fabric were evaluated by using thermo gravimetric analysis (TGA). Mechanical analysis was conducted to evaluate tensile test and three point bending test of composite. It was found that thermal degradation resistance of jute fabric was improved by coating with flexible epoxy resin. Moreover, the flexural modulus improved with increasing curative concentration. The interfacial interaction between the epoxy and PA6 was clearly indicated by the photo micrographs of the polished cross sections of the coated and uncoated jute fabric/PA6 composites.
