Grafting of maleic acid on the polyester fibres initiated by plasma at atmospheric pressure

Poly(ethyleneterephtalate) fibres (PET) have been treated by low-temperature nitrogen plasma generated in a plasma reactor that works at atmospheric pressure. After the activation in plasma, PET fibres were subsequently grafted with maleic acid (MAc) in order to enhance their adhesion to the styrene–butadiene rubber (SBR) blend. The three factors, five levels analysis by means of the statistical and regression evaluation method was used to determine the influence of the concentration of MAc on solution, rate of fibre movement through the reactor, and grafting time on weight increment after grafting, adhesion strength, mechanical and structural characteristics of fibres. As a result of the grafting, the new polar groups belonging to MAc caused the change of morphology, which was confirmed by scanning electron microscopy (SEM). These changes can lead to the better adhesion strength between PET fibres and a rubber blend.