Soluble and electrically conductive polyaniline-modified polymers: Incorporation of biocompatible polymeric chains through ATRP technique Bakhshali Massoumi, 1 Mostafa Shafagh-kalvanagh, 1 Mehdi Jaymand 2 1 Department of Chemistry, Payame Noor University, Tehran, P.O. BOX: 19395-3697, Islamic Republic of Iran 2 Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, P.O. Box: 51656-65811, Islamic Republic of Iran Correspondence to: M. Jaymand (E-mail: m_jaymand@yahoo.com or m.jaymand@gmail.com or jaymandm@tbzmed.ac.ir) ABSTRACT: This article describes the incorporation of biocompatible polymeric chains [poly(2-hydroxyethyl methacrylate) and poly(N-isopropylacrylamide)] into the polyaniline backbone through atom transfer radical polymerization technique to produce solu- ble and electrically conductive polyaniline-based materials. The chemical structures of all samples as representatives were characterized by means of Fourier transform-infrared and proton nuclear magnetic resonance spectroscopies. The electroactivity behaviors and elec- trical conductivities of the synthesized samples were verified under cyclic voltammetric conditions, and the standard four-probe meth- od, respectively. In addition, the thermal behaviors and morphologies of the synthesized samples were investigated by means of thermogravimetric analysis and scanning electron microscopy, respectively. We envision that the synthesized polyaniline-modified pol- ymers may be find applications in biomedical fields such as tissue engineering, mainly due to their water solubilities, electrical con- ductivities, and biocompatibilities. VC 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44720. KEYWORDS: ATRP; electrical conductivity; graft copolymer; polyaniline; solubility Received 3 June 2016; accepted 21 November 2016 DOI: 10.1002/app.44720 INTRODUCTION Electrically conductive polymers (ECPs) are the fourth genera- tion of polymeric materials, and this type of engineering poly- mers has recently received a great deal of interest for various practical, technological, and biomedical applications, mainly due to their unique physicochemical properties. 1–7 Among the ECPs, polyaniline (PANI) is the most promising member owing to its unique electrical conductivity, low cost synthesis, multi- redox state, high energy density, good environmental, and ther- mal stability as well as wide range of commercial and techno- logical applications such as electromagnetic interference (EMI) shielding, 8 solar cells, 9 corrosion devices, 10 biomedical scien- ces, 11 electrochromic devices, 12 organic light emitting diodes (OLEDs), 13 electrical memory performance, 14 bio/chemical sen- sors, 15 and many more. PANI can be synthesized through two main approaches including electrochemical, 16 and chemical oxi- dation 17 polymerizations in various organic solvents and/or in aqueous media in the presence of a catalyst. However, the PANI is typically rigid, and the polymer tends to aggregate, resulting in poor solubility and processability, and low mechanical flexibility. These properties are originated from the stiffness of its main chain and the existence of a strongly conjugated p electron system. Considering this fact, modifica- tion of PANI is an immensely important in modern material science, to broaden its application fields, and has been the sub- ject of many investigations. 3,18,19 To end this goal, the main approaches are as follows: 1. Monomer modification (e.g., rings and N-substituted anilines) 20 2. Doping of PANI with functional organic acids (e.g., dodecyl- benzenesulfonic acid (DBSA)) 21 3. Preparation of PANI composites with processable polymers 22 4. Incorporation of polar functional groups (e.g., sulfonation), and polymeric or long and flexible alkyl chains into the PANI backbone. 23 Copolymerization can be considered as an efficient and versatile approach to prepare polymeric materials with specific properties through the proper selection of monomers and architectural design by manipulation of constituent monomers of copoly- mers. It is now well accepted that copolymers exhibit different physicochemical characteristics in comparison with blends of the same corresponding homopolymers. 2,3,24 From this point of VC 2017 Wiley Periodicals, Inc. WWW.MATERIALSVIEWS.COM J. APPL. POLYM. SCI. 2017, DOI: 10.1002/APP.44720 44720 (1 of 10)