Thermoset characterization for moldability analysis

Abstract

The injection molding of thermosetting compounds involves complex interactions between material parameters and molding conditions, on one hand, and moldability and the ultimate properties of molded parts, on the other hand. The main role of the molding variables may be related to their effects on the cure time and temperature and on the flow and thermal phenomena that affect orientation and residual stresses. These effects are manifested in the ultimate mechanical properties and shrinkage of the molded articles. Only scattered empirical data are available on the effects of material parameters, like the basic kinetic, thermal, rheological, and pressure‐volume‐temperature properties of thermosetting compounds. The lack of useful information in this area may be related to the unavailability of sufficient, satisfactory data on the above properties. This situation has also resulted in limitations on meaningful work towards the mathematical modelling of the molding process, which would be useful for the optimization of production rates and product quality. The paper summarizes the status of work in this area with emphasis on recent results relating to kinetic, thermal, and rheological characterization of thermosetting molding compounds.

Vitrification during the Isothermal Cure of Thermosets: Comparison of Theoretical Simulations with Temperature‐Modulated DSC and Dielectric Analysis

“…to the TTT diagram in the isothermal case, can be constructed, [5][6][7][8] and is shown in MATLAB version 7.0 was used to simulate the non-isothermal cure reaction, taking into account similar considerations as for the isothermal case. [14] In the absence of vitrification, the reaction is chemically controlled and the time (t) dependence of the degree of cure (α, 0 ≤ α ≤ 1) during the reaction can be described by the equation of Kamal: [15] …”

The application of thermal analysis to the study of epoxy–clay nanocomposites

“…where α is the degree of cure and m and n are the kinetic exponents of the reaction [23]. This theoretical fit is indicated by the dash-dotted lines in Fig.…”

Time-intensity superposition for photoinitiated polymerization of fluorinated and hyperbranched acrylate nanocomposites

“…The autocatalytic model has been successfully applied to the photopolymerization kinetics of acrylates. This is a phenomenological model based on the work of Kamal [43] for thermal cure of polyesters. Although acrylate photopolymerization is not autocatalytic but autoaccelerated, the shape of the curve of reaction rate versus conversion is the same.…”