Synthesis of Polyamides from Substituted Fluorene and Diamides in the Presence of a Copper(I) Catalyst Mousa Ghaemy, Mohammad Barghamadi Faculty of Chemistry, University of Mazandaran, Babolsar, Iran Received 26 May 2008; accepted 30 July 2008 DOI 10.1002/app.29011 Published online 30 October 2008 in Wiley InterScience (www.interscience.wiley.com). ABSTRACT: 2,7-Dibromo-9,9-dioctylfluorene was synthe- sized by a two-step reaction from fluorene and n-octylboro- mide. This was reacted with benzamide for the preparation of a model compound and with terephthalamide, isophtha- lamide, and adipamide for the preparation of polyamides in the presence of a mixture of 10 mol % CuI and 20 mol % N,N 0 -dimethylethylenediamine as a catalyst and K 2 CO 3 as a base. The monomer and the model compound were charac- terized with Fourier transform infrared, proton nuclear magnetic resonance, and elemental analysis. The prepared polyamides were characterized with Fourier transform infrared, proton nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis, and solu- bility and viscosity measurements. The obtained polya- mides possessed excellent solubility in common organic solvents, and they exhibited inherent viscosities in the range of 0.93–1.19 dL/g. According to the differential scanning calorimetry analysis, the glass-transition temperatures of the polyamides were in the range of 84–154  C. Thermogravi- metric analysis indicated that a 2% weight loss of the polya- mides occurred in the temperature range of 218–253  C under a nitrogen atmosphere. V V C 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 1588–1593, 2009 Key words: polyamides; thermal properties; polyconden- sation; solubility INTRODUCTION High-performance polyamides are an important class of polymers, and their applications are growing steadily. In the last few decades, thermally stable polymers have received extensive interest because of the increasing demands for high-temperature poly- mers as replacements for metals or ceramics in the automotive, aerospace, and microelectronics indus- tries. Aromatic polyimides and polyamides (ara- mids) are certainly two of the most successful classes of high-temperature polymers. They possess thermal stability, chemical resistance, low flammabil- ity, and excellent mechanical properties. 1–6 However, it is difficult for aramids to be used as thin films and coatings because of their low solubility and high melting temperature (T m ) and glass-transition temperature (T g ) values. To obtain different proper- ties and for different applications, various structural changes have been introduced into the aramid back- bone. 7–15 The introduction of a flexible bond into the rigid polymer backbone is known to be an effective method for enhancing the solubility and also lower- ing T g and T m of these rigid polymers while mini- mizing the deterioration of their physical properties. 16–18 Another conventional approach to increasing the solubility is the introduction of bulky pendant groups into the polymer backbone. 19–25 This modification lowers T m and produces soluble and amorphous polymers. Transition-metal-catalyzed C(aryl)AN bond form- ing processes play an important role in organic syn- thesis. Transition-metal-catalyzed cross-coupling of amides with aryl halides provides a straightforward route to N-arylamides. To date, catalysts based on sev- eral transition metals have been examined for the N- arylation of amides. One example is Pd, which often requires the use of expensive, unstable, and poisonous compounds, such as phosphine ligands. Removal of palladium residues from polar reaction products can also be challenging. In recent years, there have been many reports focused on the deliberate use of ligands to facilitate the copper-catalyzed aryl amidation reac- tion. 26,27 Buchwald and coworkers 27–29 developed a general, mild, and experimentally simple method for the amidation of aryl halides by using inexpensive and air-stable copper(I) iodide and N,N 0 -dimethylated 1,2-diamine ligands as precatalysts. Polyamides are usually synthesized with common methods such as the polycondensation of dicarbox- ylic acids or diacid chlorides with diamines. For the first time, we have developed the aforementioned amidation method to prepare new polyamides by using the copper-catalyzed coupling of 9,9-dioctyl- 2,7-dibromofluorene with different amides in the presence of K 2 CO 3 as a base and CuI and N,N 0 - Journal of Applied Polymer Science, Vol. 111, 1588–1593 (2009) V V C 2008 Wiley Periodicals, Inc. Correspondence to: M. Ghaemy (ghaemy@umz.ac.ir).