Surface modification of polypropylene nonwoven using a plasma focus device for lamination with polyester and cotton nonwoven

To present a novel application of a UNU/ICTP plasma focus device for modifying the surface of a polymer in order to improve the adhesion between the components of a composite material. Polypropylene (PP) nonwoven was surface-modified using a plasma focus device operated with nitrogen gas at a pressure of 1.5 mbar. The number of plasma shots was varied from 1 to 5 shots. The plasma focus device produced reactive nitrogen plasma which bombarded the surface of the fabric at a supersonic speed. From water contact angle analysis and water absorption of PP nonwoven, it was found that surface modification by plasma caused an increase in hydrophilicity of PP. The lamination of PP and polyester/cotton (PET/C) nonwovens were carried out by compression molding at 190 ํC for 12 minutes to obtain PP-PET/C composites. The weight ratios of PP nonwoven to PET/C nonwoven were varied from 95:5, 90:10, 85:15 to 80:20. It was found that tensile and flexural properties prepared from surface-modified PP were higher than those of the composites prepared from the unmodified one. However, impact strength of both composites was comparable. The results also revealed that the composite prepared from PP nonwoven surface-modified with 4 plasma shots and PET/C nonwoven 20% by weight exhibited the optimum mechanical properties