Polyurethane networks with enhanced thermal stability and electrical insulation properties were prepared from the reaction of epoxy-terminated urethane prepolymers (EPU) and polyimides containing pendant phenol groups (HPI). EPUs were prepared by the reaction of glycidol with NCO-terminated urethane oligomers. The oligomers were prepared from different molecular weight versions of polycaprolactone polyol (CAPA) and hexamethylene diisocyanate. The progress of the reaction was monitored by differential scanning calorimetric analysis in the presence and absence of suitable catalyst. The onset temperature of exothermic reaction of phenolic groups and epoxy rings was chosen as optimum curing temperature and the reaction duration was optimized by gel content measurement. The starting materials and polymers were characterized by conventional spectroscopic methods, and physical, thermal and electrical properties of the crosslinked networks were determined. The novel poly(urethane-imide)s exhibited considerable improvement in thermal and electrical properties in comparison to common polyurethanes.
Mosiulanis, B. and Zelinski, R. (1985). Mechanical, Thermal, and Electric Properties of Polyurethaneimide Elastomers, J. Appl. Polym. Sci., 30: 2731-2741.
7.
Deligoz, H., Yalcinyuva, T. and Ozgumus, S. (2005). A Novel Type of Si-containing Poly(urethane-imide)s: Synthesis, Characterization and Electrical Properties, Eur. Polym. J., 41: 771-781.
8.
Yeganeh, H. , Atai, M., Hojati Talemi, P. and Jamshidi, S. (2006). Synthesis, Characterization and Properties of Novel Poly (urethane-imide) Networks as Electrical Insulators with Improved Thermal Stability, Macromol. Mat. Eng., 291: 883-894.
9.
Yeganeh, H. , Hojati Talemi, P. and Jamshidi, S. (2007). Novel Method for Preparation of Polyurethane Elastomers with Improved Thermal Stability and Electrical Insulating Properties, J. Appl. Polym. Sci., 103:1776-1785.
10.
Ghosh, K. L. and Mital, K. L. Eds (1996). Polyimides: Fundamentals and Applications (New York: Dekker ).
11.
Paul, D.P. and Bucknall, C.B. (2000). Polymer Blends, volume 1; Formulation (New York: J. Wiley & Sons).
12.
Utraki, L.A. (1990). Polymer Alloys and Blends ( New York: Hanser Publishers).
13.
Chen, J., Zhang, J., Zhu, T., Hua, Z., Chen, Q. and Yu, X. (2001). Blends of Thermoplastic Polyurethane and Polyether-Polyimide: Preparation and Properties, Polymer., 42: 493-1500.
14.
Zuo, M., Xiang, Q. and Takeichi, T. (1998). Preparation and Properties of Novel Poly(urethane-imide)s, Polymer, 39: 6883-6889.
15.
Zuo, M. and Takeichi, T. (1999). Preparation and Characterization of Poly(urethane-imide) Films Prepared from Reactive Polyimide and Polyurethane Prepolymer, Polymer, 40: 5153-5160.
16.
Zuo, M. and Takeichi, T. (1997). Novel Method for the Preparation of Poly(urethane-imide)s and their Properties, J. Polym. Sci. Part A: Polym. Chem., 35: 3745-3753.
17.
Iyer, N.P. , Gnanarajan, T.P. and Radhakrishnan , G. (2002). Mechanical and Thermal Properties of Networks Prepared from Reactive Poly(urethane-imide)s and Blocked Polyurethane Prepolymer, Macromol. Chem. Phys ., 203: 712-717.
18.
Chiang, W.Y. snd Tsai, C.D. (1999). Synthesis and Properties of Maleimide-erminated Polyurethane AB Crosslinked Polymers I. Polyurethane/Allyl Nonyl Novolac Resin ABCPs, Eur. Polym. J., 35: 1139-1148.
19.
Cai, Y., Jiang, Z., Yang , D. and Liu , P. (1998). Structure and thermal properties of PU/P(BMI-UBMI) IPNs, J. Appl. Polym. Sci., 68, 1689-1694.
20.
Liao, D.C. , Hsieh, K.H. and Kao , S.C. (1995). Synthesis and Characterization of Bismaleimide-polyurethane Crosslinked Copolymers , J. Polym. Sci. Part A: Polym. Chem., 33: 481-491.
21.
Liao, D.C. and Hsieh, K.H. (1994). Synthesis and Characterization of Bismaleimides Derived from Polyurethanes, J. Polym. Sci Part A: Polym Chem., 32:1665-1672.
22.
Radhakrishnan Nair, P., Rechunadhan Nair , C.P. and Francis, D.J. (1999). Effect of Imide- oxazolidinone Modification on the Thermal and Mechanical Properties of HTPB-Polyurethanes, J. Appl. Polym. Sci., 71: 1731-1738.
23.
Park, M., Jang, W., Yang, S., Shul, Y. and Han, H. (2006). Synthesis and Characterization of New Functional Poly(urethane-imide) Crosslinked Networks, J. Appl. Polym. Sci., 100: 113-123.
24.
Yeganeh, H. and Shamekhi, M.A. (2005). Preparation and Properties of Novel Polyurethane Insulating Coatings Based on Glycerin-terminated Urethane Prepolymers and Blocked Isocyanate, Polym. Int., 54: 754-763.
25.
Yeganeh, H. and Shamekhi, M.A. (2006). Novel Polyurethane Insulating Coatings Based on Polyhydroxyl Compounds, Derived from Glycolysed PET and Castor Oil, J. Appl. Polym. Sci., 99: 1222-1233.
26.
Yeganeh, H. and Moeini, H.R. (2007). Novel Polyurethane Electrical Insulator Coatings Based on Amide- Ester-Ether Polyols Derived from Castor Oil and Post-Consumed PET High. Perf. Polym. 19, 113-126.
27.
Lee, H. and Neville, K. (1967). Handbook of Epoxy Resins ( McGraw-Hill Co, New York).
28.
Yeganeh, H., lakouraj, M.M. and Jamshidi, S. (2005). Synthesis and Characterization of Novel Biodegradable Epoxy Modified Polyurethane ElastomersJ. Polym. Sci. PartA: Polym. Chem., 43: 2985-2996.
29.
Tamami, B. and Yeganeh, H. (2001). Synthesis and Characterization of Novel Aromatic Polyamides Derived from 4-aryl-2,6-bis(4-aminophenyl) pyridines, Polymer, 42: 415-420.
30.
Tamami, B. and Yeganeh, H. (2001). Preparation and Properties of Novel Polyimides Derived from 4-aryl-2,6 bis(4-amino phenyl)pyridine, J. Polym. Sci. PartA: Polym. Chem., 39: 3826-3831.
31.
Mehdipour-Ataei, S., Bahri-Laleh, N. and Amirshaghaghi , A. (2006). Comparison of One-step and Two-step Methods of Polyimidization and Substitution Effect in the Synthesis of New Poly(ester-imide)s with Bulky Pendent Group, Polym. Deg. Stab., 91: 2622-2631.
32.
Sek, D., Wanic, A. and Schab-Balkerzak , E. (1995 ). Investigation of Polyimides Containing Naphthalene Units. II. Model Compounds Synthesis, J. Polym. Sci. PartA: Polym. Chem., 33: 547-554.
33.
Sek, D., Pijet, P. and Wanic, A. (1992). Investigation of Polyimides Containing Naphthalene UnitsI. Monomer Structure and Reaction Conditions, Polymer, 33: 190-193.
34.
Hsia, H., Ma, C., Li, M., Li, Y. and Chen, D. (1994). Glycidyl-terminated Polyurethane Modified Epoxy Resins: Mechanical Properties, Adhesion Properties, and Morphology, J. Appl. Polym. Sci., 52: 1137- 1151.
35.
Han, S., Yoon, H.G., Suh , K.S., Kim , W.G. and Moon, T.J. (1999). Cure Kinetics of Biphenyl Epoxy-phenol Novolac Resin System Using Triphenylphosphine as Catalyst, J. Polym. Sci. Part: A. Polym. Chem., 37: 713-720.
36.
Treloar, L.R.G. (1949). The Physics of Rubber Elasticity (London: Oxford University Press , p.66).
37.
Klug, R.S. (1998). Magnet Wire Dissipation Factor One Layer at a Time, IEEE. Elec. Insul. Mag. 4, 24-26.
38.
Licari, J.J. and Hughes, L.A. (1990). Handbook of Polymer Coatings for Electronics Applications: Chemistry, Technology and Applications (New Jersey: Noyes Publications ).
39.
Blythe, A.R. (1979). Electrical Properties of Polymers (GB: Cambridge University Press).
