摘要
为探究不同负荷条件下尼龙6工业丝的蠕变性能差异及其形变机理,采用广角X射线衍射、小角X射线散射、红外、双折射等测试方法,研究了尼龙6工业丝在不同负荷条件下的蠕变性能差异和蠕变前后的多层次结构变化规律。结果表明:尼龙6工业丝的蠕变形变率随着负荷的增大而增大;当蠕变负荷不超过40%平均断裂负荷(ABL)时,样品的弹性回复率和蠕变速率参数基本保持不变,当蠕变负荷大于40%ABL时,样品的弹性回复率明显降低,蠕变速率参数提高。蠕变回复后样品的结晶度、晶区取向和晶粒尺寸等晶区结构参数均未发生明显变化,结构变化主要发生在非晶区结构。样品非晶区取向、片晶厚度和玻璃化转变温度随着蠕变负荷的增大而增大,尤其当蠕变负荷大于40%ABL时,蠕变后样品非晶区结构参数变化程度更为明显。取向程度较低的部分无定形分子链在蠕变负荷的作用下沿纤维轴有序排列生成取向非晶区结构,取向非晶区结构在蠕变负荷撤去后无法完全回复。
Because of their excellent heat resistance,chemical resistance,high strength,and superior elastic properties,nylon 6 industrial fibers are widely used in tire cords,cables,geomaterials,and other industrial fields.Nylon 6 industrial fibers will creep during service under load conditions.The creep process involves changes in their internal microstructure,affecting their service performance.However,the creep properties and structural changes of nylon 6 industrial fibers under different load conditions are still unclear.In this paper,the creep experiments of nylon 6 industrial fibers across various load ranges(20%-70%average breaking load,ABL)were conducted,and the difference of creep properties of nylon 6 industrial fibers under different load conditions was compared.The microstructure changes of nylon 6 industrial fibers before and after creep under different load conditions were studied by using wide-angle X-ray diffraction(WAXD),small-angle X-ray scattering(SAXS),Fourier transform infrared spectroscopy(FTIR),and birefringence techniques.It can be seen from the creep experiment that the creep deformation rate of the sample increases with the increase of the creep load.When the creep load is not more than 40%ABL,both the elastic recovery rate and creep rate of the sample remain unchanged.However,when the creep load exceeds 40%ABL,there is a decrease in the elastic recovery rate accompanied by an increase in the creep rate.In order to explore the internal structural differences caused by creep at room temperature in nylon 6 industrial fibers under different creep loads,FTIR,WAXD,and SAXS were used to analyze the crystal type transformation,crystallinity,crystallite size,crystal orientation factor,fiber long period and lamellar structure of nylon 6 industrial fibers.Combined with birefringence and dynamic mechanical analysis(DMA),the multilayer structure changes of samples before and after creep tests under different creep loads were studied.The results obtained from FTIR,WAXD,and SAXS indicate that no crystal type transformation occurred during the creep process.Additionally,no significant changes were observed in the crystal structure parameters,including crystallinity,crystallite size,and crystal orientation factor of the nylon 6 industrial fibers.After creep recovery,the changes in the crystal structure of nylon 6 industrial fibers were almost completely recovered.SAXS and birefringence results show that the creep behavior of nylon 6 industrial fibers at room temperature mainly depends on the amorphous structure.When the creep load is low(≤40%ABL),the orientation and thickness of the amorphous zone in the nylon 6 industrial fibers will recover with the removal of the creep load,and when the creep load is high(>40%ABL),the structure of the crystalline zone and the amorphous zone will recover.The orientation and thickness of the amorphous zone of nylon 6 industrial fibers will increase with the increase of creep load.This is due to the fact that the molecular chains in the amorphous region are oriented along the creep deformation under high creep load,and the molecular chains in the amorphous region with a small degree of orientation are gradually stretched and cannot be completely recovered,and some of the molecular chains in the amorphous region are transformed into oriented amorphous structures,and the thickness of the crystal region increases.
作者
何灏
张迎亮
刘宸君
殷亚然
陈康
张先明
HE Hao;ZHANG Yingliang;LIU Chenjun;YIN Yaran;CHEN Kang;ZHANG Xianming(School of Materials Science&Engineering,Zhejiang Sci-Tech University,Hangzhou 310018,China;Zhejiang Provincial Innovation Center of Advance Textile Technology,Shaoxing 312030,China)
出处
《现代纺织技术》
北大核心
2025年第1期1-9,共9页
Advanced Textile Technology
基金
浙江省“尖兵”“领雁”研发攻关计划项目(2024C01083,2023C01095)
浙江省自然科学基金探索项目(Q24E030033)
浙江省博士后科研择优资助项目(ZJ2023093)
中国纺织工业联合会科技指导性计划项目(2022006)
浙江理工大学科研启动基金项目(21212305-Y)。
