Surface Modification of Polypropylene Nonwoven Fabric with Plasma Activation and Grafting

Polypropylene fiber has the advantages of high tensile strength, excellent chemical and biological resistance and low production costs. But some drawbacks such as dyeing problems and low wettability, raised from highly crystalline and hydrophobic nature of polypropylene chain, has restricted the usage of this fiber in some applications. In this study, plasma induced grafting as an effective procedure for modifying the surface characteristics of polypropylene nonwoven fabrics has been applied. Atmospheric pressure plasma was used to generate active sites on the polymeric chains of polypropylene fibers, and then the plasma activated samples were grafted with acrylic acid. The effects of plasma treatment time, monomer concentration, grafting time and temperature on graft yield and water absorption behavior of treated samples were evaluated. To evaluate the surface morphology changes, SEM images were employed. FTIR analysis was used to examine the chemical changes made on the fabric sample surfaces. The FTIR analysis showed that carbonyl and carboxyl groups have been created on the surface of plasma treated and grafted fibers. Water absorption of untreated and plasma grafted samples were evaluated using contact angle measurements. The results show that water absorption of plasma grafted polypropylene nonwoven samples has been improved significantly.