Synthesis and properties of new ferrocene-modified urethane block copolymers

• Published in: Journal of applied polymer science Vol. 76; no. 13; pp. 1847 - 1856
• Main Authors: Najafi-Mohajeri, N., Nelson, G. L., Benrashid, R.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 24-06-2000; Wiley
• Subjects: Applied sciences; electrochemistry; Exact sciences and technology; ferrocene; fire retardancy; Inorganic and organomineral polymers; Physicochemistry of polymers; polyurethane block copolymers; Preparation; Ferrocene derivative copolymer; Polychelate; Organometallic copolymer; Urea derivative copolymer; Experimental study; Redox polymer; Urethane copolymer; Oxygen index; Polyaddition; Thermal stability; Thermal properties; Ester copolymer; Electrochemical properties; Smoke emission; Preparation; Amide copolymer; Block copolymer
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/(SICI)1097-4628(20000624)76:13<1847::AID-APP1>3.0.CO;2-M

Polyurethane polymers are a wide class of materials, ranging from surface coatings and adhesives to flexible or rigid foams. However, polyurethanes in general are very flammable and produce heavy smoke when burning. As a result of their flammability, there is a great interest in the development of materials with improved fire retardance. In this study a series of new ferrocene urethane block copolymers based on diphenylmethane‐4,4′‐diisocyanate were synthesized and their fire retardant behavior studied using thermogravimetric analysis (TGA), differential scanning calorimetry, cone calorimetry, and the oxygen index. Ferrocene‐modified block copolyurethanes showed a 40–80% reduction in peak heat release rate compared to an unmodified sample. In addition, the TGA results showed that ferrocene‐modified polymers have high thermal stability and ferrocene enhances char formation in air and helium. The synergistic effect of silicone and phosphorus with ferrocene was also discussed. The solution electrochemical behavior of ferrocene‐containing polymers was studied using cyclic voltammetry. These polymers showed a reversible wave at E° ≈ 0.771–0.852 V and the electron transfer was diffusion controlled. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1847–1856, 2000