The Research Of Surface Modification And Cohesiveness Of Domestic Polyimide Fiber Via Low Temperature Plasma

Polyimide refers to a class of polymers containing amide rings in the main chain of molecules,because of its excellent rigid molecular structure,with good mechanical properties,high temperature resistance,radiation resistance,can be widely used in aerospace,microelectronics,environmental protection and many other fields.However,because its molecular rigidity is too strong,the macromolecular chain lacks active groups,resulting in a smooth SURFACE of PI fiber,poor wetting,and weak binding ability with other materials.Therefore,this project adopts the low temperature plasma modification method,the surface modification of PI fiber is carried out,and the surface performance change of fiber and its fabric is studied.This project uses a single-factor analysis method to study the effect of three factors on the fracture strength of PI fiber and surface friction performance from three different angles:discharge power,discharge time and discharge voltage,so as to determine the level required for orthogonal experiment.Secondly,this project uses orthogonal experiment and range analysis to analyze the optimization scheme of fiber stretch performance,surface friction performance and wetting performance-discharge power230W,discharge time 240s,strong discharge voltage 15Pa.Then,four different treatment options samples of untreated,lighter treatment,better treatment,heavy treatment were selected and observed by SEM microscope,XPS energy spectrometer and infrared spectrometer on surface.The results show that:low-temperature plasma modification will be etched on the PI fiber,so that the surface of the fiber appears a ripple-like protrusion;In addition,low-temperature plasma modification will make the proportion of C elements on the surface of the fiber reduced,O element and N element proportion increased;After low-temperature plasma modification,the surface of the fiber appeared C=O,COOH and other new function groups,at the same time hydroxyl,ammonia content has been increased.This project focuses on the bond performance of PI fibers and PI fabrics treated with low-temperature plasma,and shows the changes of fiber bonding performance and fabric bonding performance through the peeling strength and peeling working of fiber and polytetrafluoroethylene and the peeling power and peeling working of nano-metal film and fabric.The study found that under the treatment of the better solution A₃B₃C₁,that is,a discharge power of 230 W,a discharge time of 240 s,and a discharge voltage of 15 Pa,the peel work of PI fiber and polytetrafluoroethylene film increased by 43.97%compared to the untreated sample,and the replacement work was similar Untreated treatment increased by 59.45%,and the separation of the fabric from the nano-metal film was strongly cut.The fabric not treated with low-temperature plasma treatment was increased by 17.78%,and the replacement work ratio was increased by 32.13%.The peeling strength of the fabric and the nano-metal film is 17.78%higher than that of the non-low temperature plasma treated fabric,and the peeling power is 32.13%higher than that.At the same time,the subject also studied the wear resistance of coated fabrics subjected to low-temperature plasma pretreatment.The study found that low temperature plasma pretreatment can improve the wear resistance of coated fabrics.In addition,the subject also used the SPSS statistical software to analyze the relationship between static friction factor,dynamic friction factor and fiber peeling strength,peeling working of PI fibers.The analysis shows that there is correlation between the static and dynamic friction factors of PI fibers and the fiber stripping strength.The multivariate fitting function formula for the static and dynamic friction coefficient of PI fiber surface and the peeling strength of PI fiber is y=3.105+17.843x.The square of the correlation coefficient is 0.732.The subject also studied the effect of low temperature plasma pretreatment on the conductivity of coated PI fabrics and the effect of time on the effect of low temperature plasma on the treatment of PI materials.The study found that low-temperature plasma pretreatment can improve the conductivity of coated PI fabrics;the modification effect of low-temperature plasma on PI materials will weaken as the storage time increases,and under the same time and conditions,PI fibers The modification effect decreases faster than PI fabric.