Polyphenylene sulfide (PPS) fiber plasma treatment can improves hydrophilicity. PPS is a high polymer composed of alternating benzene rings and sulfur atoms. PPS material is known as the "plastic gold" and is the most cost-effective engineering plastic to date. It is known as the sixth largest general-purpose engineering plastic. PPS is divided into coating grade, injection grade, and fiber grade. PPS fiber is one of the high-performance fibers, which has excellent temperature resistance, corrosion resistance, flame retardancy, and good mechanical properties. The unique structure of PPS gives it high structural properties, with a crystallinity of up to 50%~85%, making it have good mechanical properties and dimensional stability, and minimal deformation during use. PPS fibers have excellent chemical corrosion resistance, especially outstanding resistance to non oxidizing acids and hot alkaline solutions. They are almost insoluble in any solvent below 200 ℃ and can maintain high performance even under extremely harsh conditions. PPS fibers have excellent strength, rigidity, and fatigue resistance at high temperatures, and can be continuously used at 200-240C. They are relatively stable in air and nitrogen below 400 ℃ without any quality loss. PPS fiber products are difficult to burn, with a maximum oxygen index value of 34%, and can meet UL-94V-0 standards without the need for flame retardants. Despite its numerous advantages, PPS also has some shortcomings. PPS has no polar groups in its macromolecular structure, resulting in low surface free energy and surface tension. At the same time, the cross-section of the fibers is circular, with a dense structure and a lack of micropores and gaps. Therefore, PPS is a typical hydrophobic material. The poor hydrophilicity of PPS limits the application of PPS fibers and fabrics in the field of water electrolysis membranes. Therefore, hydrophilic modification of PPS is an urgent task that needs to be addressed.

Plasma surface treatment is the process of using various particles in plasma to bombard the surface of PPS fibers for surface etching. At the same time, active particles such as excited molecules, ions, and free radicals in plasma react with the surface of the material to introduce functional groups and improve its performance. Treating PPS fabric with O2 as the plasma discharge atmosphere can introduce oxygen-containing polar groups on the surface of PPS material, improving its hydrophilic properties.

The process flow of plasma treatment

Turn on the power of the plasma processing machine, insert the pre processed PPS fabric sample, and then close the processing chamber. Under an O2 atmosphere, set different discharge powers, processing times, and working pressures to perform plasma treatment on the PPS fabric.

Principle of plasma treatment

O2 plasma contains free electrons and oxygen-containing active particles. During the plasma treatment of PPS fibers, numerous active particles collide with the fabric surface, causing partial chemical bond breakage and generating free radicals. These radicals combine with oxygen-containing active particles or react with 0 in the air after treatment, introducing -0H on the fabric surface to improve the hydrophilicity of PPS fibers.