| Polyimide(PI)have brilliant comprehensive properties due to its own structure,and it had attracted attention and research in many fields.And high-strength and high-modulus PI fibers have the advantages of material and organic fiber properties.The prepared fabrics have the characteristic of high strength,lightness,flexibility,and environmental resistance,and they are the good raw material for aerospace,bulletproof protection and other fields.In the application process,PI fibers are often presented in the form of fabrics,and then processed by coating,compounding,etc.to obtain the final product.However,due to the limitation of the surface-free state and characteristics of high-strength and high-modulus PI fiber products on the market,its wear resistance is difficult to satiate the requirements of smooth weaving,and the surface polarity of the fabric is low,and the interface bonding is poor when it is composited with other materials.Therefore,in order to improve the weaving and surface treatment technology of PI fibers,the weaving process of PI fibers and the surface modification of fabrics were studied in this experiment,which expanded new methods for the weaving and application of PI fibers.The main results of this reaserch are as follows:The surface physicochemical characteristics and fabric weaving process of high-strength and high-modulus PI fibers were studied.In the experiment,high-strength and high-modulus PI fiber(S35-200D)was used for twisting,sizing,weaving,and desizing treatment.The findings show that the optimum twist of the fiber is 80 twists/m,and the abrasion resistance can be increased by 17.8 %.The best sizing conditions: the solid content of the sizing agent is15 %,the tensile strength of the fiber is 23.06 c N/dtex,the wear resistance with the quartz roller is increased by 12.8 %,and the wear resistance between fibers is increased by 276.3 %;the sizing speed is 90 m/min.Under the condition of hydrothermal desizing,The desizing rate of fabrics treated by hydrothermal desizing at 80 ℃ for 1 h can reach 94.9 %,and temperature is the main factor affecting desizing.The fabric surface treatment technology is studied.The effect of alkaline solution on the surface properties of PI fabrics was investigated.Using 4mol/L NaOH solution,under the conditions of different treatment time(0～5min)and different temperatures(30～50 ℃),the surface properties and tensile properties of the fabric before and after treatment were compared,and the optimal treatment temperature and time were obtained.The results show that the optimal conditions for PI fabric treating are: concentration was 4 mol/L,temperature was 50 ℃,time was 1 min or temperature was 30 ℃,time was 5min.At this conditions,the water contact angles of the fabrics are 82.3 ° and84.6 °,respectively,which are reduced by about 20 %,and the mechanical properties of the fabrics can still be maintained at a loss rate of less than 5 %on this conditions.The effects of different kinds of silane coupling agents on the surface properties of PI fabrics were studied.The PI fabrics were treated by four kinds of silane coupling agents(KH550,KH560,KH570,KH602)with different concentrations(0～10 wt%).The results show that the feedback of the water contact angle after treating by KH550(KH602)with the change of the mass fraction is not obvious..The change of water contact angle and mass fraction of the fabric after KH560 and KH570 treatment It was negatively correlated.Changing the treatment time of the coupling agent solution,the water contact angle of the fabric did not change obviously.The tensile test found that the treated fabric can still maintain the original tensile properties..It`s say that KH560 and KH570 coupling agents are more suitable for PI fabric treatment than KH550 and KH602,and the coupling agent treatment effect is mild. |
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