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 0.46–0.71？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 310–345°C and the decomposition temperature under the nitrogen atmosphere for 10% weight-loss temperatures in excess of 488°C. 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 [1–3]. Aromatic polyimides are an important class of heterocyclic polymers with remarkable heat resistance and superior mechanical and electrical properties, and also durability [4–6]. 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
References
[1]
J. Tan, C. Wang, W. Peng, G. Li, and J. M. Jiang, “Synthesis, characterization, and properties of novel aromatic polyamides containing phthalazinone moiety,” Polymer Bulletin, vol. 62, no. 2, pp. 195–207, 2009.
[2]
K. L. Mittal, Polyimides: Synthesis, Characterization and Application, Plenum, New York, NY, USA, 1984.
[3]
M. J. M. Abade, Ed., Polyimides and Other High-Temperature Polymers, Elsevier, New York, NY, USA, 1991.
[4]
A. Banihashemi and A. Abdolmaleki, “Novel aromatic polyimides derived from benzofuro[2,3-b]benzofuran-2,3,8,9- tetracarboxylic dianhydride (BBTDA),” European Polymer Journal, vol. 40, no. 8, pp. 1629–1635, 2004.
[5]
M. K. Ghosh and K. L. Mittal, Eds., Polyimide: Fundamentals and Applications, Marcel Dekker, New York, NY, USA, 1996.
[6]
D. Wilson, M. D. Stenzenberger, and P. Hergenrother, Polyimides, Blackie, Glasgow, UK, 1990.
[7]
S. Tamai, A. Yamaguchi, and M. Ohta, “Melt processible polyimides and their chemical structures,” Polymer, vol. 37, no. 16, pp. 3683–3692, 1996.
[8]
S. H. Hsiao and C. T. Li, “Synthesis and characterization of new adamantane-based polyimides,” Macromolecules, vol. 31, no. 21, pp. 7213–7217, 1998.
[9]
F. Li, J. J. Ge, P. S. Honigfort et al., “Dianhydride architectural effects on the relaxation behaviors and thermal and optical properties of organo-soluble aromatic polyimide films,” Polymer, vol. 40, no. 18, pp. 4987–5002, 1999.
[10]
D. S. Reddy, C. H. Chou, C. F. Hsu, and G. H. Lee, “Synthesis and characterization of soluble poly(ether imide)s based on 2, -bis(4-aminophenoxy)-9, -spirobifluorene,” Polymer, vol. 44, pp. 557–563, 2003.
[11]
N. R. Legge, G. Holden, and H. E. Schroeder, Thermoplastic Elastomers, Hanser, New York, NY, USA, 1987.
[12]
A. Noshay and I. E. McGrath, Block Copolymers, Academic Press, New York, NY, USA, 1977.
[13]
N. Berard and A. S. Hay, “Division of Polymer Chemistry, American Chemical Society,” Polymer Preparation, vol. 34, p. 148, 1993.
[14]
J. Van Wang, G. X. Liao, C. Liu, and X. G. Jian, “Poly(ether imide)s derived from phthalazinone-containing dianhydrides,” Journal of Polymer Science A, vol. 42, no. 23, pp. 6089–6097, 2004.
[15]
L. Cheng, H. Wu, L. Ying, X. L. Yang, and X. G. Jian, “New soluble aromatic polyamides from non-symmetrical extended diacid containing a phthalazinone moiety,” Designed Monomers and Polymers, vol. 7, pp. 225–234, 2004.
[16]
X. H. Li and A. S. Hay, “Synthesis of a high molecular weight fluorinated poly(phthalazinone ether) by self-condensation of an AB-type monomer,” Macromolecules, vol. 39, pp. 3714–3716, 2005.
[17]
X. H. Zhang, S. Chen, Y. Q. Min, and G. R. Qi, “Synthesis of novel bisphenol containing phthalazinone and azomethine moieties and thermal properties of cured diamine/bisphenol/DGEBA polymers,” Polymer, vol. 47, no. 6, pp. 1785–1795, 2006.
[18]
L. Cheng, L. Ying, J. Feng, C. Y. Wang, J. L. Li, and Z. Xu, “Novel heterocyclic poly(arylene ether ketone)s: synthesis and polymerization of 4-( -hydroxyaryl)(2H)phthalazin-1-ones with methyl groups,” Journal of Polymer Science A, vol. 45, pp. 1525–1535, 2007.
[19]
M. B. Talawar, R. Sivabalan, T. Mukundan et al., “Environmentally compatible next generation green energetic materials (GEMs),” Journal of Hazardous Materials, vol. 161, no. 2-3, pp. 589–607, 2009.
[20]
S. Paria, “Surfactant-enhanced remediation of organic contaminated soil and water,” Advances in Colloid and Interface Science, vol. 138, no. 1, pp. 24–58, 2008.
[21]
S. Keskin, D. Kayrak-Talay, U. Akman, and ？. Horta？su, “A review of ionic liquids towards supercritical fluid applications,” Journal of Supercritical Fluids, vol. 43, no. 1, pp. 150–180, 2007.
[22]
H. Nakagawa, Y. Fujino, S. Kozono et al., “Application of nonflammable electrolyte with room temperature ionic liquids (RTILs) for lithium-ion cells,” Journal of Power Sources, vol. 174, no. 2, pp. 1021–1026, 2007.
[23]
A. Abdolmaleki, “Synthesis and characterization of some new polyhydrazides by direct polycondensation in ionic liquid,” Iranian Polymer Journal, vol. 16, no. 11, pp. 741–751, 2007.
[24]
Q. Shi, Y. Zhang, G. Jing, and J. Kan, “Properties of polyaniline synthesized in ionic liquid (1-ethyl-3- methylimidazoliumethyl sulphate),” Iranian Polymer Journal, vol. 16, no. 5, pp. 337–344, 2007.
[25]
C. Arbizzani, F. Soavi, and M. Mastragostino, “A novel galvanostatic polymerization for high specific capacitance poly(3-methylthiophene) in ionic liquid,” Journal of Power Sources, vol. 162, no. 1, pp. 735–737, 2006.
[26]
A. S. Shaplov, E. I. Lozinskaya, I. L. Odinets et al., “Novel phosphonated poly(1,3,4-oxadiazole)s: synthesis in ionic liquid and characterization,” Reactive and Functional Polymers, vol. 68, no. 1, pp. 208–224, 2008.
[27]
J. T. Gorke, K. Okrasa, A. Louwagie, R. J. Kazlauskas, and F. Srienc, “Enzymatic synthesis of poly(hydroxyalkanoates) in ionic liquids,” Journal of Biotechnology, vol. 132, no. 3, pp. 306–313, 2007.
[28]
S. Mallakpour and E. Kowsari, “Ionic liquids as novel solvents and catalysts for the direct polycondensation of N,N′ -(4,4′ -Oxydiphthaloyl)bis-L-phenylalanine diacid with various aromatic diamines,” Journal of Polymer Science A, vol. 43, no. 24, pp. 6545–6553, 2005.
[29]
S. Mallakpour and E. Kowsari, “Microwave heating in conjunction with ionic liquid as a novel method for the fast synthesis of optically active poly(amideimide)s derived from N,N′-(4,4′-hexafluoroisopropylidenediphthaloyl)-bis-Lmethionine and various aromatic diamines,” Iranian Polymer Journal, vol. 15, p. 239, 2006.
