Statistical evaluation of non-isothermal decomposition kinetics analysis methods for AIBN

Abstract

Decomposition kinetics parameters were obtained from non-isothermal DSC data for the decomposition of AIBN by two data analysis methods. A statistical evaluation of the results showed that there was no difference between the results obtained by each data analysis method and that the heating rate did not significantly affect the values of the kinetics parameters. Both data analysis methods isolate the order of reaction, n, the activation energy, E, and the Arrhenius factor, A, from a single non-isothermal scan of the decomposition reaction.A number of techniques have been developed for measuring kinetics constams of chemical reactions from DSC data. The primary advantage of these techniques is their speed and simplicity, In recent years, research efforts in reaction kinetics analysis have centered on differential data analysis methods based on isothermal [1-3], temperature variant or dynamic [4][5], and multiple scan methods [6][7]. Each method uses the rate of heat evolution as the computational parameter, implicitly assuming, among other things, that the reaction is not autocatalytic, has one rate limiting step, and is unaffected by changes in reactant concentration.Even though much has been written about the theoretical validity and general applicability of non-isothermal reaction kinetics analyses by DSC [8][9][10][11][12], particularly to thermoset cure [13][14][15], non-isothermal techniques have gained broad acceptance for a variety of uses. Although non-isothermal kinetics analysis techniques are widely accepted, there are remarkably few published analysis which verify the precision and validity of the techniques. While tests of the accuracy and validity of non-isothermal kinetics are generally difficult exoerimentally, statistical analyses of the run-to-run precision of non-isothermal kinetics analysis are straight forward. In this work we assess the precision of the results obtained by two nonisothermal data analysis methods for the degradation of 2,2'-azobjs-(isobutyronitrile) (AIBN).

Thermal characterization of polyester–melamine coating matrices prepared under nonisothermal conditions

“…DMTA is particularly useful for the characterization of individual networks in interpenetrating polymer networks (IPNs) 18, 19. Provder and coworkers20–22 deduced that increased chemical heterogeneity (the appearance of shoulders and doublets in the tan δ curves) would result in an increase in the impact strength. Sluszny et al23 and Takeichi et al24 also used thermal methods, including dynamic viscoelastic measurements, to characterize novel semi‐IPNs and polymer blends.…”