Cure kinetics FTIR study of epoxy/nickel–imidazole system

✍ Scribed by A. Omrani; L. C. Simon; A. A. Rostami; M. Ghaemy

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 525 KB
• Volume: 40
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.20350

✦ Synopsis

Abstract

In the first part of this work (Omrani et al., T__hermochim__ A__cta__ 2008, 468, 39–48), we have reported mechanism and curing behavior of diglycidyl ether of bisphenol A (DGEBA) cured with a nickel salt of imidazole. In the present study, the isothermal cure of DGEBA–Im~6~NiBr~2~ system was investigated by in situ FTIR spectroscopy. Different amounts of nickel salt were loaded into epoxy matrix to elucidate the effects of the nickel catalyst concentration on the cure kinetics and mechanism. First‐order kinetic analysis was applied to estimate the rate constants for the both steps, adduct formation and chain‐growth polymerization, in the mechanism. It has been concluded that at high nickel salts concentrations, the studied cure reaction behaves like free‐imidazole‐epoxy cure. Analysis of the activation energy showed that the second step in the mechanism is more sensitive to the level of nickel salt than the first one. Using transition state theory, the thermodynamic functions of activated complex were also estimated. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 663–669, 2008