Toughness improvement of epoxy networks by nanophase-separating antiplasticizers

• Published in: Journal of applied polymer science Vol. 123; no. 6; pp. 3437 - 3447
• Main Authors: Laiarinandrasana, L., Fu, Y., Halary, J. L.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.03.2012; Wiley; Wiley Subscription Services, Inc
• Subjects: Additives; antiplasticizer; Antiplasticizers; Applied sciences; Chemical properties; Crack initiation; Engineering Sciences; epoxy-amine network; Exact sciences and technology; Fracture mechanics; Fracture toughness; Materials; Materials science; nanophase separation; Nanostructure; Networks; Polymer industry, paints, wood; Polymers; Properties and testing; Stiffness; Technology of polymers; toughening; Strengthening; Fracture mechanics; toughening; Mechanical properties; Alcohol; Curing (plastics); Experimental study; Modeling; Glass transition temperature; Fracture toughness; Thermal properties; Additive; epoxy-amine network; nanophase separation; Concentration effect; Antiplasticizer; Epoxy-amine network; antiplasticizer; fracture mechanics
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.34646

Two epoxy‐amine networks were toughened by using a nanophase separating antiplasticizer at various contents ranging from 0 to 20 mol % with respect to the epoxide. These model networks were chosen to differ markedly by their glass transition temperature in the absence of additive, namely 180°C and 114°C. Net stress was measured as a function of crack opening displacement on single edge notch bending specimens. Analysis of the experimental data yielded both stiffness and fracture toughness. In addition, fracture surfaces were observed by scanning electron microscopy. Effect on both stiffness and toughness of network characteristics (nature of the hardener, amount of additive) were carefully examined. Conditions were found for which fracture energy at crack initiation substantially increases without any detrimental effect on stiffness. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012