%0 Journal Article
%T Ionic Liquid-Catalyzed Preparation of Aromatic Polyamides Containing Phthalazinone Moiety
%A Saeed Zahmatkesh
%J ISRN Polymer Science
%D 2012
%R 10.5402/2012/121984
%X An unsymmetrical heterocyclic dicarboxylic acid monomer, 4-[4-(4-carboxy phenoxy)-naphthyl]-2-(4-carboxyphenyl) phthalazin-1-one (1) was successfully prepared. A series of polyamides containing phthalazinone were prepared from the prepared dicarboxylic acid with various aromatic diamines in an ionic liquid (IL) as a green, safe, and eco-friendly medium and also reactions catalysis agent. Evaluation of data shows that IL is the better polyamidation medium than the reported method and the catalysis stands on the higher inherent viscosities and yields of the obtained PAs and the rate of polymerizations beyond the greener reaction conditions and deletion of some essential reagents in conventional manner. Characterization was performed by means of 1H-NMR and FT-IR spectroscopy, elemental analysis, thermogravimetric analysis, and differential scanning calorimetric techniques. Molecular weights of the obtained polyamides were evaluated viscometrically, and the measured inherent viscosities were in the range of 0.46¨C0.71£¿dL/g. These polyamides were readily soluble in many organic solvents. These polymers still keep good thermal stability with high glass transition temperatures in the range of 310¨C345¡ãC and the decomposition temperature under the nitrogen atmosphere for 10% weight-loss temperatures in excess of 488¡ãC. 1. Introduction Due to the increasing demands for high-performance polymers as a replacement for ceramics or metals in the microelectronic, aerospace and automotive industries, and thermally stable polymers have received much interest over the past decade. Polyimides and their copolymers are certainly one of the most useful classes of high-performance polymers, which have found many applications in industries [1¨C3]. Aromatic polyimides are an important class of heterocyclic polymers with remarkable heat resistance and superior mechanical and electrical properties, and also durability [4¨C6]. Poor thermoplastic fluidity and solubility are the major problems in wide application of polyimides. This makes it impossible for most polyimides to be directly processed in their imidized forms; thus, their applications have been restricted in some fields. Processable engineering plastics possessing moderately high softening temperatures and/or solubility in some organic solvents are required for practical use. Therefore, various efforts have been focused on the preparation of soluble and/or thermoplastic polyimides, while still maintaining the excellent thermal and mechanical properties. Typical approaches have been employed to improve the processability of
%U http://www.hindawi.com/journals/isrn.polymer.science/2012/121984/