Study On Water And Oil Repellent Finishing Of Polysulfonamide Fabric

Polysulfonamide (PSA) is a new kind of high temperature resistance fiber developed and produced by Shanghai Textile Science Research Institute and Shanghai Synthetic Fiber Research Institute. The LOI (Limiting Oxygen Index) of PSA is 33, which indicates that PSA has good fire retardant performance. PSA, our own-patented synthetic fiber, which can resist the temperature above 250℃, has filled the blank of high temperaure fiber in China. It has good performance of fire retardant, flame resistance, thermal stability and resistance to cauterization. PSA is mainly applied in protective products, filtering materials, insulation products, etc. With the annual market demand of 2000 tons, PSA fiber has a bright prospect. It is proved that PSA can be a high temperature resistant textile material, flame retardant textile material and household textile material.The existence of Acylamino on the macromolecular structure of the PSA leads to good hydrophilicity of PSA. But it is not suitable to be used in the damp and contaminated environment. So we consider improving PSA's wet-repellency, dirt repellency and self-cleaning capability by water and oil repellent finishing. This dissertation discusses the necessity of water and oil repellent finishing of the PSA fabric. After the treatment, the PSA fabric can be applied in industries and adornments, such as tarp. Water and oil repellent finishing can expand PSA's utilization, and is meaningful for the development of high-performance fiber industry in its popularization and application.Based on the study of water and oil repellent finishing technics of cotton, polyester/cotton, wool fabric, this dissertation takes the characteristics of the PSA's water and oil repellent finishing as a break-through point. The discussion towards the surface tension has determined the measurements of the finishing of the PSA fabric. The PSA fabric is treated by water and oil repellent organic fluorine AG-7600 and cross-linking agent melamine formaldehyde resin. According to Uniform-precision Rotatble Central Composite Design, it is analyzed in the dissertation that different parameters influence the effect of the finishing effect, and optimized parameters are obtained. These optimized parameters are amended by the experiment on the dosage of cross-linking agent. The optimum results are as follows: the volume percentage of AG-7600 is 5%, the volume percentage of melamine formaldehyde resin is 1%, the curing temperature is 170℃, while the curing time is 1 min.After treating the PSA fabric with the amended optimum finishing parameters, we carried out performance comparison experiments of the finished and original fabric, including the testing of tenacity, water vapour permeability, air permeability and so on. The numerical value of the significance testing after finishing shows a little drop in the performances of PSA fabric. The average warp tenacity is reduced by 4.5%, the average weft tenacity is reduced by 4.8%, the average air permeability is reduced by 11.73%, and the average water vapor transmission is reduced by 10.21%. We also carried out the burning retardant test on the finished PSA fabric. The performance numbers only have a slight difference with the untreated ones. The warp afterglow time is raised by 0.7s, the warp damaged length is raised by 0.7mm. The weft afterglow time is raised by 0.7s, the weft damaged length is raised by 0.7mm. It shows that the water and oil repellent finishing hardly influences the flame retardant of the PSA fabric.During the course of finishing, appending a cross-linking agent to the finishing agent is an important measure for the durability. The finished fabric, after 5, 10 and 15 washing cycles, can keep the original water repellent grade and also the oil repellent grade. Even after 30 washing cycles, the water repellent grade remains at 8 while the oil repellent grade remains at 6. The durability test shows that the PSA fabric acquires good water and oil repellent function as well as good durability.The dissertation has carried out pilot study on the water and oil repellent finishing of the PSA fabric and has obtained ideal results by optimization. After the significance testing of the finishing fabric, the results shows that the finishing scarcely changes the original characteristics and the functions.