A new class of wholly aromatic and optically active polyamides (PAs) having phthalimide and L-leucine pendant groups were synthesized via polycondensation of chiral diacid, (2S)-5-[4-(4-methyl2-phthalimidylpentanoyl-amino)benzoylamino]isophthalic acid and different aliphatic and aromatic diisocyanates. Polymerization reactions were performed both in the presence of dibutyltin dilaurate as a catalyst and without a catalyst, using molten tetrabutylammonium bromide (TBAB) as a green solvent, and was compared with polymerization in 1-methyl-2-pyrrolidone as a conventional solvent. The resulting polymers were obtained in good yields and inherent viscosities ranging between 0.26 and 0.96 dL g-1. These polymers are optically active, thermally stable and readily soluble in amide-type solvents. All of the above polymers were characterized by Fourier transform infrared spectroscopy, specific rotation and in some cases by 1H-NMR and elemental analysis techniques. Thermal properties of PAs were evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry. TGA showed that the 5% weight loss temperature in a nitrogen atmosphere for two representative samples were more than 283 and 354 °C, which indicates that the resulting PAs have good thermal stability.
Russo, S., Bianchi, E., Congiu, A., Mariani, A. and Mendichi, R. ( 2000). A Study on the N-allylation Reaction of Aromatic Polyamides. 1. Poly(p-phenylene terephthalamide), Macromolecules, 33: 4390- 4397.
2.
Pal, R.R. , Patil, P.S., Salunkhe, M.M., Maldar, N.N. and Wadgaonkar , P.P. (2005). Synthesis and Characterization of Aromatic Polyamides Containing an S-triazine Ring with Thiophenoxy Linkages, Polym. Int., 54: 569-575.
3.
Sugi, R., Yokoyama, A., Furuyama, T., Uchiyama, M. and Yokozawa, T. ( 2005). Inductive Effect-Assisted Chain-Growth Polycondensation. Synthetic Development from para- to meta-Substituted Aromatic Polyamides with Low Polydispersities, J. Am. Chem. Soc., 127: 10172-10173.
4.
Liaw, D.J. , Liaw, B.Y. and Yang, C.M. (2001). Synthesis and Characterization of New Soluble Cardo Aromatic Polyamides Bearing Diphenylmethylene Linkage and Norbornyl Group, Macromol. Chem. Phys., 202: 1866-1872.
5.
Jikei, M. and Kakimoto, M.A. ( 2001). Hyperbranched Aromatic Polyamides Prepared by Direct Polycondensation, High Perform. Polym., 13: S33-S43.
6.
Jikei, M., Chon, S.H., Kakimoto, M.A., Kawauchi, S., Imase, T. and Watanebe, J. ( 1999). Synthesis of Hyperbranched Aromatic Polyamide from Aromatic Diamines and Trimesic Acid, Macromolecules, 32: 2061-2064.
7.
Alvarez, J.C. , de la Campa, J.G., Lozano, A.E. and de Abajo, J. (2001). Thermal and Mechanical Properties of Halogen-Containing Aromatic Polyamides, Macromolecules , 202: 3142-3148.
8.
Franklin, P.J., Goldenberg, W.S., Ducatman, A.M. and Franklin, E. (2000). Too Hot to Handle: An Unusual Exposure of HDI in Specialty Painters, Am. J. Ind. Med., 37: 431-437.
9.
Molander, P., Thomassen, A., Lundanes E., Fladseth, G., Thorud, S., Thomassen, Y. and Greibrokk, T. ( 2001). Determination of 1-(2-Methoxyphenyl)-piperazine Derivatives of Airborne Diisocyanates by Packed Capillary Liquid Chromatography with Pre-column Large-volume Enrichment, J. Sep. Sci., 24: 947-954.
10.
Jang, A.S., Choi, I.S., Koh, Y., Moon, J.D. and Lee, K. ( 2000). Increase in Airway Hyperresponsiveness Among Workers Exposed to Methylene Diphenyldiisocyanate Compared to Workers Exposed to Toluene Diisocyanate at a Petrochemical Plant in Korea, Am. J. Ind. Med., 37: 663-667.
11.
Mallakpour, S. and Rafiee, Z. (2008). Application of Microwave-assisted Reactions in Step-growth Polymerization: A Review, Iranian Polym. J., 17: 907-935.
12.
Mallakpour, S. and Rafiemanzelat , F. (2008). Synthesis, Characterization and Properties of a Series of Copoly(amide-imide-ether-urethane)s with a New Hard Segment Constituent: Study of the Effect of Hard Segment Content , High Perform. Polym., 20: 146-165.
13.
Itsuno, S. ( 2005). Chiral Polymer Synthesis by Means of Repeated Asymmetric Reaction, Prog. Polym. Sci., 30: 540-558.
14.
Nakano, T. (2001). Optically Active Synthetic Polymers as Chiral Stationary Phases in HPLC, J. Chromatogr A., 906: 205-225.
15.
Chankvetadze, B., Yamamoto, C., Kamigaito, M., Tanaka, N., Nakanishi, K. and Okamoto, Y. (2006). High-performance Liquid Chromatographic Enantioseparations on Capillary Columns Containing Monolithic Silica Modified with Amylose tris(3,5-dimethylphenylcarbamate), J. Chromatogr A., 1110: 46-52.
16.
Okamoto, Y., Yashima, E., Hatada, K. and Mislow, K. (1984). Chromatographic Resolution of Perchlorotriphenylamine on (+)-Poly(triphenylmethyl methacrylate), J. Org. Chem., 49: 557-558.
17.
Zheng, J. , Bragg, W., Hou, J., Lin, N., Chandrasekaran , S. and Shamsi, S.A. (2009). Sulfated and Sulfonated Polysaccharide as Chiral Stationary Phases for Capillary Electrochromatography and Capillary Electrochromatography-mass Spectrometry , J. Chromatogr A., 1216: 857-872.
18.
Lao, W. and Gan, J. (2006). High-performance Liquid Chromatographic Separation of Imidazolinone Herbicide Enantiomers and Their Methyl Derivatives on Polysaccharide-coated Chiral Stationary phases, J. Chromatogr A., 1117: 184-193.
19.
Zhong, Q. , Han, X., He, L.Beesley, T.E., Trahanovsky W.S. and Armstrong D.W. (2005). Chromatographic Evaluation of Poly (trans-1,2-cyclohexanediyl-bis acrylamide) as a Chiral Stationary Phase for HPLC, J. Chromatogr A., 1066: 55-70.
20.
Zhu, Y.J., Wang, W.W., Qi, R.J. and Hu, X.L. (2004). Microwave-Assisted Synthesis of Single-Crystalline Tellurium Nanorods and Nanowires in Ionic Liquids, Angew. Chem., 116: 1434-1438.
21.
Tang, H., Tang, J., Ding, S., Radosz, M. and Shen, Y. ( 2005). Atom Transfer Radical Polymerization of Styrenic Ionic Liquid Monomers and Carbon Dioxide Absorption of the Polymerized Ionic Liquids , J. Polym. Sci, Part A: Polym. Chem, 43: 1432-1443.
22.
Zhao, H., Xia, S. and Ma, P. ( 2005). Use of Ionic Liquids as ‘Green’ Solvents for Extractions, J. Chem. Technol. Biotechnol., 80: 1089-1096.
23.
Li, J. , Zhang, J. and Liu, Z. (2006). Bimodal Molecular Weight Distribution of Poly(styrene-co-acrylonitrile) Formed by Conventional Free-Radical Copolymerization of Acrylonitrile and Styrene in Room Temperature Ionic Liquids , J. Polym. Sci., part A: Polym. Chem., 44: 4420-4427.
24.
Mallakpour, S. and Kowsari, E. (2006). 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′-Hexafluoroisopropylidene diphthaloyl)-bis-Lmethionine and Various Aromatic Diamines, Iranian Polym. J., 15: 239-247.
25.
Mallakpour, S. and Rafiee, Z. (2007). Efficient Combination of Ionic Liquids and Microwave Irradiation as a Green Protocol for Polycondensation of 4-(3-Hydroxynaphthalene)-1,2,4-triazolidine-3,5-dione with Diisocyanates , Polymer, 48: 5530-5540.
26.
Mallakpour, S. and Rafiee, Z. (2007). Tetrabutylammonium Bromide: An Efficient, Green and Novel Media for Polycondensation of 4-(4-Dimethylaminophenyl)-1,2,4-triazolidine-3,5-dione with Diisocyanates, Eur. Polymer. J., 43: 1510-1515.
27.
Khodaei, M.M., Khosropour, A.R. and Ghozati, K. (2004). A Powerful, Practical and Chemoselective Synthesis of 2-anilinoalkanols Catalyzed by Bi(TFA)3 or Bi(OTf)3 in the Presence of Molten TBAB, Tetrahedron. Lett. , 45: 3525-3529.
28.
Khalafi-Nezhad, A. and Mokhtari, B. (2004). Tetrabutylammonium Bromide: an Efficient Media for Dimethoxytritylation of the 5′-Hydroxyl Function of Nucleosides, Tetrahedron. Lett., 45: 6737-6739.
29.
Kantevari, S. , Venu Chary, M., Rudra Das, A.P., Vuppalapati, S.V.N. and Lingaiah , N. (2008). Catalysis by an Ionic Liquid: Highly Efficient Solvent-free Synthesis of Aryl-14H-dibenzo[a.j]xanthenes by Molten Tetrabutylammonium Bromide under Conventional and Microwave Heating , Catal. Commun., 9: 1575- 1578.
30.
Gonzalez, I., Bouquillon, S., Roglans, A. and Muzart, J. ( 2007). Palladium and Rhodium-catalyzed Intramolecular [2+2+2] Cycloisomerizations in Molten Tetrabutylammonium Bromide, Tetrahedron. Lett., 48: 6425-6428.
31.
Sun, D. and Zhai, H. ( 2007). Polyoxometalate as Co-catalyst of Tetrabutylammonium Bromide in Polyethylene glycol (PEG) for Coupling Reaction of CO2 and Propylene Oxide or Ethylene Oxide, Catal. Commun., 8: 1027-1030.
32.
Mallakpour, S. and Sepehri, S. (2008). Synthesis and Characterization of New Optically Active Polyesters by Step-Growth Polymerization of Novel Aromatic (2S)-4-[(4-Methyl-2-phthalimidylpentanoylamino) benzoylamino]isophthalic Acid with Aromatic Diols, J. Appl. Polym. Sci., 110: 2942-2949.
33.
Mallakpour, S. and Dinari, M. (2008). Microwave Step-growth Polymerization of 5-(4-Methyl-2-phthalimidylpentanoylamino)isophthalic Acid with Different Diisocyanates, Polym. Adv. Technol., 19: 1334- 1342.
34.
Mallakpour, S. and Taghavi, M. (2008). A Facile, Microwave-Assisted Synthesis of Novel Optically Active Polyamides Derived from 5-(3-Methyl-2-phthalimidylpentanoylamino)isophthalic acid and Different Diisocyanates, Eur.Polym. J., 44: 87-97.
35.
Van Krevelen, D.W. and Hoftyzer, P.J. (1976). Properties of Polymers , 3rd edition, Elsevier, Scientific Publishing, New York.
