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
以尼龙66(PA66)和植酸(IP6)为前驱体、乙酸为溶剂,采用溶剂热法制备了PA66基碳点(66CDs)。利用TEM、FTIR、XPS、荧光光谱对其进行了表征,对其光学性能、离子稳定性和时间稳定性进行了测试,探究了其指纹识别、荧光防伪、光线阻挡的应用...以尼龙66(PA66)和植酸(IP6)为前驱体、乙酸为溶剂,采用溶剂热法制备了PA66基碳点(66CDs)。利用TEM、FTIR、XPS、荧光光谱对其进行了表征,对其光学性能、离子稳定性和时间稳定性进行了测试,探究了其指纹识别、荧光防伪、光线阻挡的应用。结果表明,将1.6 g PA66、1.1 g IP6加入20 mL乙酸中,于260℃下反应36h,制备的66CDs具有最大荧光强度。66CDs为球形结构,平均粒径4.00nm,表面含有羧基、羟基、氨基等官能团;66CDs的荧光为非激发波长依赖型,最佳激发波长和发射波长分别为360和490 nm,荧光量子产率可达11.69%,其荧光强度不受常见金属阳离子影响,30 d内具有稳定性。由66CDs与水溶性淀粉制备的荧光粉末可用于指纹识别,不仅可将66CDs制成油墨用于荧光防伪,还可将其制成防蓝光膜,用于蓝光防护。展开更多
Analysis of isothermal and nonisothermal crystallization kinetics of nylon 66 was carried out using differential scanning calorimetry (DSC). The commonly used Avrami equation and that modified by Jeziorny were used, r...Analysis of isothermal and nonisothermal crystallization kinetics of nylon 66 was carried out using differential scanning calorimetry (DSC). The commonly used Avrami equation and that modified by Jeziorny were used, respectively, to fit the primary stage of isothermal and nonisothermal crystallizations of nylon 66. In the isothermal crystallization process, mechanisms of spherulitic nucleation and growth were discussed. The lateral and folding surface free energies determined from the Lauritzen-Hoffman treatment are sigma = 9.77 erg/cm(2) and sigma (e) = 155.48 erg/cm(2), respectively; and the work of chain folding is q = 33.14 kJ/mol. The nonisothermal crystallization kinetics of nylon 66 was analyzed by using the Mo method combined with the Avrami and Ozawa equations. The average Avrami exponent (n) over bar was determined to be 3.45. The activation energies (DeltaE) were determined to be -485.45 kJ/mol and -331.27 kJ/mol, respectively, for the isothermal and nonisothermal crystallization processes by the Arrhenius and the Kissinger methods.展开更多
The analysis of the small angle X ray scattering(SAXS) data was based upon particle characteristic function, one dimensional electron density correlation function and particle distribution function. The microstruct...The analysis of the small angle X ray scattering(SAXS) data was based upon particle characteristic function, one dimensional electron density correlation function and particle distribution function. The microstructure of nylon 66 with different degrees of crystallinity was studied by means of X ray scattering method. The radius of gyration R g, the Porod radius R p, the thickness of crystalline region L c, the thickness of non crystalline region L a, the thickness of interphase region d tr , the long period L , the semiaxises of particles( a, a, b ), the distribution of the particle sizes and the scattering invariant were calculated. The results indicate that there was a significant interphase region between the crystalline region and the non crystalline region, and its content( W t,x ) should not be neglected in comparison with that of crystalline region W c,x . The morphology of nylon 66 prepared by isothermal crystallization at a high temperature was mainly a lamellar structure, while the spherical crystals dominated in the quenched sample. The size of the particles in the quenched sample was smaller than that of those in the isothermally crystallized sample, and the distribution of the particle sizes in the isothermally crystallized sample was wider.展开更多
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.
文摘以尼龙66(PA66)和植酸(IP6)为前驱体、乙酸为溶剂,采用溶剂热法制备了PA66基碳点(66CDs)。利用TEM、FTIR、XPS、荧光光谱对其进行了表征,对其光学性能、离子稳定性和时间稳定性进行了测试,探究了其指纹识别、荧光防伪、光线阻挡的应用。结果表明,将1.6 g PA66、1.1 g IP6加入20 mL乙酸中,于260℃下反应36h,制备的66CDs具有最大荧光强度。66CDs为球形结构,平均粒径4.00nm,表面含有羧基、羟基、氨基等官能团;66CDs的荧光为非激发波长依赖型,最佳激发波长和发射波长分别为360和490 nm,荧光量子产率可达11.69%,其荧光强度不受常见金属阳离子影响,30 d内具有稳定性。由66CDs与水溶性淀粉制备的荧光粉末可用于指纹识别,不仅可将66CDs制成油墨用于荧光防伪,还可将其制成防蓝光膜,用于蓝光防护。
基金This research was funded by the National Natural Science Foundation of China and subsidized by the Special Funds for Major State Basic Research Projects (G1999064800).
文摘Analysis of isothermal and nonisothermal crystallization kinetics of nylon 66 was carried out using differential scanning calorimetry (DSC). The commonly used Avrami equation and that modified by Jeziorny were used, respectively, to fit the primary stage of isothermal and nonisothermal crystallizations of nylon 66. In the isothermal crystallization process, mechanisms of spherulitic nucleation and growth were discussed. The lateral and folding surface free energies determined from the Lauritzen-Hoffman treatment are sigma = 9.77 erg/cm(2) and sigma (e) = 155.48 erg/cm(2), respectively; and the work of chain folding is q = 33.14 kJ/mol. The nonisothermal crystallization kinetics of nylon 66 was analyzed by using the Mo method combined with the Avrami and Ozawa equations. The average Avrami exponent (n) over bar was determined to be 3.45. The activation energies (DeltaE) were determined to be -485.45 kJ/mol and -331.27 kJ/mol, respectively, for the isothermal and nonisothermal crystallization processes by the Arrhenius and the Kissinger methods.
基金Supported by the Key Project of National Natural Science Foundation of China(No. 2 99340 72 ) and subsidized by theSpecial Fund for Major State Basic Research Projects(No.G19990 6 4 80 6 ) .
文摘The analysis of the small angle X ray scattering(SAXS) data was based upon particle characteristic function, one dimensional electron density correlation function and particle distribution function. The microstructure of nylon 66 with different degrees of crystallinity was studied by means of X ray scattering method. The radius of gyration R g, the Porod radius R p, the thickness of crystalline region L c, the thickness of non crystalline region L a, the thickness of interphase region d tr , the long period L , the semiaxises of particles( a, a, b ), the distribution of the particle sizes and the scattering invariant were calculated. The results indicate that there was a significant interphase region between the crystalline region and the non crystalline region, and its content( W t,x ) should not be neglected in comparison with that of crystalline region W c,x . The morphology of nylon 66 prepared by isothermal crystallization at a high temperature was mainly a lamellar structure, while the spherical crystals dominated in the quenched sample. The size of the particles in the quenched sample was smaller than that of those in the isothermally crystallized sample, and the distribution of the particle sizes in the isothermally crystallized sample was wider.
