Curing kinetics of liquid crystalline 4, 4′-diglycidyloxybiphenyl epoxy with various diamines. (2nd April 2019)

• Record Type: Journal Article
• Authors: Yeo, Hyeonuk
• Is Part Of: Polymer. Volume 168(2019)
• Page Start: 209
• Page End: 217
• Publication Date: 2019-04-02
• Subjects: Epoxy -- Hardener -- Thermosets -- Curing -- Kinetics; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2019.02.058
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Liquid-crystalline epoxy resins (LCERs) have been attracting much attention due to their interesting properties. Nevertheless, 4, 4′-diglycidyloxybiphenyl (BP) epoxy containing the simplest mesogen structure has only been investigated with a limited number of curing agents. In this study, the kinetic behavior of BP during curing with various aromatic diamines was analyzed by differential scanning calorimetry to provide insight that may lead to increased applicability. It was confirmed that the starting temperature of the curing reaction decreases with the increasing basicity of the amines since initiation of the curing reaction begins entirely via an SN 2 mechanism. However, the autocatalytic behavior exhibited different characteristics for each diamine, resulting in differences in the kinetic behavior. Moreover, the kinetic parameters such as rate constant and activation energy for each system were determined by fitting the experimental data to an autocatalytic curing model. The information presented here will broaden the applicability and versatility of LCERs. Graphical abstract: Image 1080 Highlights: A library of curing systems for liquid crystalline BP epoxy is provided by investigating common diamine systems. Curing kinetics for each system is comprehensively analyzed by DSC studies using autocatalytic curing model. A well-defined linear relationship between p K b of diamines and curing starting temperatures is confirmed. Kinetic parameters for each system such as rate constant, and activation energy are determined. The information provides practical guidelines for optimizing curing condition and controlling reaction of BP epoxy.