Research On Water- And Oil-repellent And Antioxidant Performance Of Polyphenylene Nonwoven Sulfide Filter Materials

Polyphenylene sulfide (PPS) material is a thermoplastic polymer and PPS fiber has the excellent properties of high temperature resistance, chemical resistance, flame retardancy, excellent mechanical properties, and so on. Therefore, PPS non-woven filter material is widely used in some high temperature industrial gas filtration. High temperature industrial gas often contains some oxygen, PPS filter material can be more easily oxidized under high temperature and oxygen for a long time, resulting in large molecular chain rupture and fiber breakage. Meanwhile, the oxidizing gas in the industrial gas which containing much more moisture easily condenses into acid dew on the surface of PPS fiber and the filter material can be easily damaged, leading filter bag breakage. Besides, the oil mist and oil droplets in the flue gas are easy to be bonded with materials such as dust on the surface of the filter material, ash removal inconvenience thus shortening the service life of filter material. Response to this case, improving water- and oil-repellent and antioxidant properties, reducing the droplets(acid dew, oil droplet, etc.) attach to the fiber surface and oxidation corrosion can be helpful to extend its service life, meanwhile, this work is also an important significance in the process of scientific research and actual production.PPS filter material was finished through the single factor and orthogonal experiment with water-and oil-repellent agent. The optimum process conditions obtained by experiments were determined as followed:The concentration of finishing agent was 40g/L, curing temperature was 180℃ and curing time was 5min. Results showed that the finished material had superior water- and oil-repellent property and its antioxidant property also had improved.In order to improve the antioxidant property of the PPS filter material, adding a certain percentage of Polytetrafluroethylene(PTFE) dispersion and additives in water- and oil-repellent agent. The optimum process conditions obtained through SEM, oxidation resistance, water- and oil-repellent and contact angle measurement, etc., as followed:The concentration of compound finishing agent was 70g/L, curing temperature was 180℃ and curing time was 5min. Under this coating process, the oxidation resistance of PPS filter material had little improvement and it also had superior water-and oil-repellent property.The surface foam coating of PPS filter material was conducted with PTFE dispersion, adding a certain proportion of foaming agent, adhesives, etc., and the effect of coating on the structure and properties of PPS filter material were studied. The results of scanning electron microscopy indicated that a lay of compact and porous coating formed on the surface of the PPS filter material after coating treatment. The antioxidant property of PPS filter after coating had a little improvement. Filtration efficiency and aperture test showed the coated PPS material its filtering performance was improved, while the size of aperture was smaller. The coated material had no water- and oil-repellent property while its wear durability was improved highly.Summing up all the tests results obtained the better water- and oil-repellent finishing process on PPS filter material:The concentration of coating agent is 40g/L, rolling over rate: 80%-85%, pre-drying at 90℃ for 3min, curing temperature was 180℃ and curing time was 5 min. The better oxidant finishing process on PPS filter material:The concentration of compound agent was 70g/L, rolling over rate:80%-90%, pre-drying at 90℃ for 3min, curing temperature was 180℃ and curing time was 5min. Foam coating process on PPS filter material:Foaming temperature was about 160℃-170℃, rate of foaming was about 1:4, pre-drying at 80℃ for 2min, curing temperature was 140℃ and curing time was 3 min.