Abstract:
Blending different polymers is a well-known method to tailor material properties for specific applications requiring a unique set of characteristics. However, most polymers are immiscible and require the addition of a compatibilizer to promote better adhesion between phases. From an industry perspective, this method implies the use of chemistry techniques to manufacture the compatibilizer, commonly a graft copolymer miscible with both components, adding additional cost and complexity. In this work, we further study a proposed novel method for compatibilization of a PP-PA6 blend by applying an in-situ plasma treatment, comparing it with the standard use of PP-g-MAH as a compatibilizer for this blend. Plasma is widely used as a surface modification technique, known to introduce polar oxygen groups such as C−O, C=O and O−C=O to the polymer. It has the advantage of being a physical process and not requiring any reagents or solvents, thus more environmentally friendly. An air atmospheric pressure plasma jet (APPJ) was applied during compounding, introducing the same groups into the bulk structure of the polymers to promote the formation of hydrogen bonds between phases [9]. Pure PP was also melt-treated in an internal mixer to evaluate the introduction of functional groups. ATR-FTIR analysis showed the presence of C−O, C=O, and -OH bands, indicating the formation of carboxyl or ester groups. The plasma-treated blends presented a slight increase in mechanical properties over the untreated blends, explained by a finer phase dispersion observed through SEM images.
