Mannich base: a cost effective, low temperature curing agent for epoxides

Purpose ‐ Epoxy curing agents are used to cure epoxy resins by reacting with the epoxide groups or by promoting self-polymerisation of the epoxy by catalytic action. Application characteristics and final physical properties can be tailored by the choice of curing agent. The purpose of this study was to reduce the cost of epoxy hardeners (polyamide and Mannich base, which are commercially available) without affecting the properties of epoxy system and which are also useable as low temperature curing in flooring. Design/methodology/approach ‐ To prepare cost effecting Mannich base curatives for low temperature working environment without significantly affecting the properties such as toughening, adhesion, chemical resistance, etc. various compositions were made by incorporating liquid epoxy resin. Findings ‐ Mannich base curatives were prepared by using different amounts of phenol/bisphenol-A, formaldehyde and polyamines to obtain products having different amine value, viscosity and colour. Liquid epoxy resin was cured by these Mannich base hardeners prepared. Drying time of relevant thin films was observed. These curatives showed excellent curing property at low temperature as well high humid conditions. Research limitations/implications ‐ Mannich base curatives, used in present work was synthesised from phenol, DETA and dimethylamino propylamine. Besides, it could be synthesised from other phenol derivative such as cresol, resorcinol and cardanol. In the same manner, we can use other polyamines such as ethylenediamine. Practical implications ‐ The method provided a simple and practical solution to reducing the cost of Mannich base hardener without significantly affecting the desired properties. Originality/value ‐ The method used to prepare Mannich-based hardener was cost affective and could find numerous applications in protective coatings.