Tunable Contact Angle Properties of Polyaniline Enriched Epoxy/Unsaturated Polyester Blend

This chapter mainly deals with the contact angle properties of epoxy resin and an unsaturated polyester blend enriched with polyaniline microparticles by varying the ratio of unsaturated polyester and polyaniline. Polyaniline microparticles are prepared via oxidative polymerization. An elemental study using energy-dispersive X-ray analysis (EDX) was conducted on polyaniline microparticles. The particle size study clearly shows that the average particle size of polyaniline was determined to be 106.9 nm. Characterization was done for the prepared polyaniline microparticles, blends, and composites using Fourier transform infrared spectroscopy (FTIR) in order to find the existence of functional groups. The distribution of polyaniline microparticles in the matrix of pure epoxy and epoxy/unsaturated blends was studied using scanning electron microscopy (SEM). The SEM images show smooth surfaces for pure epoxy and epoxy/unsaturated polyester blends, but increased roughness with the addition of polyaniline to the matrix. The fabricated film’s mechanical properties, such as elongation at break and tensile strength, were assessed using a universal testing machine. The results indicate that the addition of 0.1% of polyaniline microparticles increased tensile strength, whereas the addition of unsaturated polyester decreased it. The tensile strength decreases with the further addition of polyaniline microparticles because of their reduced solubility in the polymer matrix. Water contact angle studies were done using a goniometer. It was noted that the fabricated blends have increased hydrophobicity. The water contact angle was significantly affected by the addition of polyaniline to the epoxy/unsaturated polyester matrix, which changed the nature of the fabricated blends from hydrophilic to hydrophobic (81.5° to 102.3°).