Thermal Activation of Mendable Epoxy through Inclusion of Microcapsules and Imidazole Complexes. (22nd January 2016)

• Record Type: Journal Article
• Authors: Tripathi, Manorama; Dwivedi, Raman; Kumar, Devendra; Roy, Prasun Kumar
• Is Part Of: Polymer-plastics technology and engineering. Volume 55:Number 2(2016)
• Page Start: 129
• Page End: 137
• Publication Date: 2016-01-22
• Subjects: Epoxy -- latent hardener -- microcapsule -- microencapsulation -- selfhealing; Polymers -- Periodicals; Polymerization -- Periodicals; Polymers -- Periodicals; Engineering -- Periodicals; Plastics -- Periodicals; 668.9
• DOI: 10.1080/03602559.2015.1070866
• Languages: English
• ISSNs: 0360-2559

Abstract

ABSTRACT: Epoxy resin was encapsulated in poly(urea–formaldehyde) microcapsules using an in situ dispersion polymerization technique. The efficiency of Ni and Cu–imidazole complexes as latent hardeners was compared to that of 2-methylimidazole. Calorimetric studies revealed higher reactivity of the nickel complex toward oxirane functionalities. Both the complexes could effectively cure the epoxy released from within the microcapsules in the event of damage followed by thermal treatment. The curing could be effected at lower temperature ( T onset = 145°C) using [Ni(2-Me-ImidH)4 Cl]Cl as compared to [Cu(2-Me-ImidH)4 Cl]Cl ( T onset = 152°C). A healing efficiency of 100 ± 2% could be achieved at 30% microcapsule loading, irrespective of the type of metal complex used. GRAPHICAL ABSTRACT: