Method for time-temperature-transformation diagrams using DSC data: Linseed aliphatic epoxy resin

• Published in: Journal of applied polymer science Vol. 131; no. 15; pp. np - n/a
• Main Authors: Restrepo-Zapata, Nora Catalina, Osswald, Tim A., Hernández-Ortiz, Juan P.
• Format: Journal Article
• Language: English
• Published: Hoboken, NJ Blackwell Publishing Ltd 05-08-2014; Wiley; Wiley Subscription Services, Inc
• Subjects: Applied sciences; Chemical properties; crosslinking; Cures; Differential Scanning Calorimetry; Diffusion; Epoxy resins; Exact sciences and technology; kinetics; Materials science; Mathematical models; Methodology; Polymer industry, paints, wood; Polymers; Properties and testing; Ramps; Reaction kinetics; Technology of polymers; thermosets; Differential scanning calorimetry; Epoxy resin; TTT diagrams; Organic anhydride; Curing (plastics); Experimental study; Modeling; Glass transition temperature; Thermal properties; Kinetic model; Concentration effect; Plant origin; thermosets; Numerical simulation; Kinetics; Measurement method; Activation energy; crosslinking
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.40566

ABSTRACT
A novel method to generate time–temperature–transformation (TTT) diagrams from Differential Scanning Calorimetry (DSC) data is presented. The methodology starts with dynamical DSC information to obtain the total transformation heat, followed by an isothermal‐dynamic temperature ramp that allows the inclusion of diffusion‐controlled reaction kinetic. The cure kinetics is modeled using an auto‐catalytic Kamal–Sourour model, complemented with a Kissinger model that allows the direct prediction of one energy of activation, DiBenedetto's equation for the glass transition temperature as a function of the cure degree and adjusted reaction constants to include diffusion mechanisms. The methodology uses a nonlinear least‐squares regression method following J.P. Hernández‐Ortiz and T.A. Osswald's methodology (J. Polym. Eng. 2004, 25, 23). A typical linseed epoxy resin (EP) presents two different kinetics control mechanisms, thereby providing a good model to validate the proposed experimental and theoretical method. TTT diagrams for EPs at two different accelerator concentrations are calculated from direct integration of the kinetic model. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40566.