Original Article Studies the behaviors of polyaniline on the properties of PS/PMMA blends Nehad N Rozik 1 , Aman I Khalaf 1 and Azza A Ward 2 Abstract The effect of dispersion of polyaniline on the mechanical, morphology, electrical, and thermal properties of the PS/PMMA blends prepared by solution casting fabrication process was investigated. PS/PMMA (50/50) wt% blend with 3% pluronic and 1% polyaniline gave the best tensile strength in comparison with other blends. So, different concentrations from polyaniline (1, 3, 5, 10, 15, and 20 wt%) were evaluated to obtain the suitable effective concentrations that can be used. The morphology suggests that 3% pluronic and 1% polyaniline can act as mechanical compatibilizer between PS and PMMA as well as a thermodynamic compatibilizer. The thermal stability of the PS/PMMA (50/50 wt%) blend with different concentrations of polyaniline in the presence of 3% pluronic was studied using thermogravimetric analysis, which showed an increase in thermal stability due to the presence of polyaniline. The dielectric investigations reflected an increase in both the permittivity and dielectric loss with increasing the content of polyaniline (PANI), due to interfacial polarization and conductivity effects. In addition the increase in the conductivity of the composites is related to the increase of the conductive paths among the filler. The pathway of conductive filler was easy to form lower percolation threshold of the composite due to betterdispersion of PANI. However, composites with low percolation threshold will be favorites for the practical applications with regard to the less deteriorated mechanical properties and processability. Keywords Polystyrene, polymethyl methacrylate, polyaniline, blend, mechanical and dielectric properties Date received: 13 January 2015; accepted: 19 March 2015 Introduction The mixture of two or more polymers to produce a blend or a composite is an efficient industrial strategy not only for the plastics industry but also for many other industries where the use of such products is becoming increasingly more common. Conducting polymers have been the subject of fundamental scien- tific interest due to their immense application poten- tial. Polyaniline (PANI) is an attractive conducting polymer due to its considerable conductivity, easy synthesis route, and good thermal stability. The main disadvantage for its industrial use is related to its powdered form, resulting in low processability and poor mechanical properties. A way of overcoming this problem is to prepare blends of PANI with insulating polymers to obtain suitable materials for being used in potential applications. 1,2 Most pairs of polymers are immiscible with each other. Even worse is the fact that they also have less compatibility than would be required in order to obtain the desired level of properties and performance from their blends. Compatibilizers are often used as additives to improve the compatibility of immiscible polymers and thus improve the morphology and the properties of their blends. Similarly, it is often challenging to disperse fillers effectively in the polymer matrix of a composite or to adhere layers of polymers to each other or to other substrates (such as glass or metals) in laminates. Continued progress in the devel- opment of compatibilization technologies is, hence, crucial in enabling the polymer industry to reap the full benefits of such approaches to obtaining materials with optimum performance and cost characteristics. 3 These blends can be prepared by chemical (casting or melting) or electrochemical methods. 4 Blending of two polymers having different proper- ties is usually producing a new polymeric material. These new polymeric material may possess the prop- erties of both polymers. The properties of polymer blends such as toughness, strength, dielectric 1 Polymer & Pigments Department, National Research Centre, Giza, Egypt 2 Microwave Physics and Dielectric Department, National Research Centre, Giza, Egypt Corresponding author: Nehad N Rozik, Polymer & Pigments Department, National Research Centre, 33 El Bohouth st. (former El Tahrir st.), Dokki, Giza, Egypt. Email: nehad.naem@yahoo.com Proc IMechE Part L: J Materials: Design and Applications 0(0) 1–11 ! IMechE 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1464420715581196 pil.sagepub.com