Cure parameters

Bose, A. B., Shaik, R., and Mawdsley, J. Optimization of the performance of polymer electrolyte fuel cell membrane electrode assemblies Roles of curing parameters on the catalyst and ionomer structures and morphology. Journal of Power Sources 2008 182 61-65. 

The run-to-run reproducibility of the profile shape of the FOCS fluorescence-intensity signal is good however, the reproducibility of the absolute intensity values is unsatisfactory. The run-to-run variations in the fluorescence intensities are caused by the differences in resin thickness at the small area "viewed" by the optrode. In addition, substantial resin flow takes place during cure, causing the resin thickness to vary as a function of cure time. However, since this variation in resin thickness mi t be reproducible from run-to-run (if other cure parameters remain unchanged), it may be possible to develop a suitable... 

Curemeters are usually run under isothermal conditions to determine cure parameters at the temperature(s) of interest. Rosea and Vergnaud123 investigated the use of a temperature ramp as being a more efficient way of obtaining kinetic parameters. 

The sophisticated oscillating die instruments can continue the measurement of dynamic properties after full cure has been reached. ASTM D6601124 covers measurements both during and after cure. A sealed cavity instrument is specified with amplitude 0.2° during cure and 1 to 100% strain after cure. In addition to the usual cure parameters, the in and out of phase moduli and tan 8 are reported. 

Figure 3.5. Dependencies of the parameters tjo (1) and Go (2) of the four-constant model on time in the process of curing (parameters Gp and 6p are the same as shown in Figure 3.4).

Potyrailo, R. A., Olson, D. R., Medford, G., Brennan, M. J., Development of combinatorial chemistry methods for coatings high-throughput optimization of curing parameters of coating libraries, Anal. Chem. 2002, 74, 5676-5680. 

TABLE 14.9 Curing Parameters and Properties of Microwave Cured Epoxy Adhesives34... 

Rico, E., Toldra, F., and Flores, J. (1990). Activity of cathepsin D as affected by chemical and physical dry-curing parameters. Z. Lebensm. Unters. Forsch. 191, 20-23. 

Among physicochemical methods for studying curing processes, rheokinetics is the closest to calorimetry, also yielding combined characteristics of the chemical dynamics of the process. Due to this, there was carried out a comparison of quantitative curing parameters obtained by rheological and calorimetric methods. 

The adhesive properties of epoxy resins coupled with their dielectric behavior have made them attractive to the electronic industry. The evaluation of thermally cured rubber modified epoxy thermosets has been the subject of recent studies (1, 2), which dealt with the dependence of morphology on the curing parameters, e.g., catalyst, cure schedule, time of gelation, etc. This work utilizes one of the new series of photocationic initiators (PCI) developed by Crivello, et al (3) which are presently commercially available. These onium salts initiate the reaction by absorbing the actinic radiation, generating radicals and producing a protonic acid. The radicals can lead to polymerization of olefinic moieties (4) while the acid initiates the polymerization of the epoxy groups (3). 

The basis of the method described by Hands and HorsfaU [1] consists of calculating the tanperature distribution as a function of lime first, thoi evaluating the dis-ttibution of the cure. Taking a temperature profile, a technique is described enabling the evaluation of the state of cure. When the form of the relationship between cure and temperature history is known, the basic cure parameters can be obtained from experiments in which temperature varies with time. When the relationship is not known, it is preferable to conduct experiments at various fixed temperatures in order to separate the dependence on time and temperature. An apparatus was built for measuring cure as a function of time at a constant temperature. The data obtained from this isothermal apparatus and a new mathematical model of cure was used to predict the cure distribution obtained in nonisothermal experiments. 

The data presented show that a proper selection of modifiers and curing parameters makes it possible to develop heat resistant composites with high temperature resistance. The composites are superior to similar materials based on BPA/ECH epoxy and epoxynovolak resins. 

Optimization of processing conditions (curing parameters) in fabrication of UV-cured automotive organic protective coatings fluorescence of a viscosity-sensitive molecular probe monitored during curing of coatings... 

Most of the information which has been published in this field is in the form of patents and, consequently, the importance of compositional changes and cure parameters on final properties and product structure are only vaguely understood inmost instances. Nonetheless, some discussion of the prior art is desirable for the reader in order to be able to view our current results in the proper perspective. 

Because of the large number of factors that influence the durability of adhesive-bonded joints, a durability test should be conducted on all systems before they are selected for any particular application. This test should include the adherends, surface preparation, adhesive, and cure parameters needed for each application. ... 

F. Avalos, J. C. Ortiz, R. Zitzumbo, M. A. Lopez-Manchado, R. Verdejo, and M. Arroyo, Effect of montmorillonite intercalant structure on the cure parameters of natural rubber. European Polymer Journal, 44 (2008), 3108-15. 

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