Conducting graft copolymers of pyrrole and thiophene with random copolymers of methyl methacrylate and 3-methylthienyl methacrylate Yusuf Guner a , Levent Toppare a, * , Yesim Hepuzer b , Yusuf Yagci b, * a Department of Chemistry, Middle East Technical University, 06531 Ankara, Turkey b Department of Chemistry, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey Received 15 December 2003; received in revised form 31 March 2004; accepted 31 March 2004 Available online 9 June 2004 Abstract Random copolymers of 3-methyl thienylmethacrylate and methyl methacrylate were synthesized via free radical polymerization. Electro-copolymerizations of random copolymers with thiophene and/or pyrrole were carried out in acetonitrile–tetrabutylammonium tetrafluoroborate (TBAFB), water–p-toluene sulfonic acid (PTSA) solvent–electro- lyte couples. Oxidative polymerization of thiophene functionalized random copolymer was also achieved by constant current electrolysis and chemical polymerization. The characterizations were done by conductivity measurements, cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermal gravimetry analysis (TGA), scanning electron microscopy (SEM). Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Electrochemical polymerization; Conducting copolymers; Graft copolymers 1. Introduction Conducting polymers (CPs) are an exciting new class of electronic materials, which have attracted rapidly increasing interest since Shirakawa’s report in 1977 [1]. CPs are beginning to find applications in the fields of battery materials [2], electrochromic devices [3,4], elec- tromagnetic shielding [5], sensor technology [6], non- linear optics [7], molecular electronics [8] and enzyme immobilization matrices [9,10] since they have combined properties of metals and polymers. Many unsubstituted conducting polymer systems have limited solubility and are intractable and infusible. This is due to the rigid rod nature of CPs, arising from their extended-delocaliza- tion. In order to make the polymer soluble, fusible and processable, polythiophene substitution at three and/or four position was achieved by various groups [11,12]. Synthesis of conducting polymer composites, graft and block copolymers were shown to be effective ways to compensate for the certain deficiencies of conducting polymers like poor mechanical and physical properties. Electropolymerization of the conducting component on an electrode previously coated with the insulating polymer is one of the most widely used method for that purpose [13–15]. Recently, conducting copolymers of thiophene func- tionalized methyl methacrylate with thiophene and/or pyrrole have been utilized [16,17]. In this work, syn- theses of random copolymers (RC) of 3-methylthienyl methacrylate (MTM) and methyl methacrylate (MMA) were achieved by free-radical polymerization with the use of azobisisobutyronitrile (AIBN) as the initiator. Conducting graft copolymerization of random copoly- mers with thiophene and/or pyrrole was achieved by * Corresponding authors. Tel.: +90-212-285-3241; fax: +90- 212-285-6386. E-mail addresses: toppare@metu.edu.tr (L. Toppare), yu- suf@itu.edu.tr (Y. Yagci). 0014-3057/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.eurpolymj.2004.03.029 European Polymer Journal 40 (2004) 1799–1806 www.elsevier.com/locate/europolj EUROPEAN POLYMER JOURNAL