Curing schematic diagram

FIGURE 11.16 Schematic diagram of cure rate versus scorch time for various commercial accelerators. (From Zhao, J., Ghebremeskel, G.N., and Peasley, J., A Smdy of EPDM/SBR Blends, presented at a meeting of the Ruhher Division, American Chemical Society, Chicago, IL, April 1999, Paper No. 16.)... 

Figure 1. Schematic diagram of specially designed fixtures used to measure, in situ, the evolving rheological properties during UV curing. The sample is placed between the two quartz plates and the incident UV radiation exiting the liquid light guide is reflected by the mirror through the plates and onto the sample.

Fig. 5. Schematic diagram for the process of surface graft polymerization of GMA onto GA and subsequent reaction with amine curing agent in EMC...

After application of the chemical finish, the fabric must be dried and if necessary, the finish must be fixed to the fibre surface, usually by additional heating in a curing step. A schematic diagram of a pad-dry-cure process is... 

Fig. 5 Schematic diagrams of effect of extent of reaction on viscosity and morphology in curing of thermosets. (A), Effect of extent of reaction on viscosity. (From Refs. " l) (B) Effect of extent of reaction on morphology. (From Refs. ° l)...

Figure 4.1. A schematic diagram of structural development during thermoset cure from (a) unreacted monomers, (h) formation of initial links, (c) the gel point or a path of covalent links across the sample and (d) the cured crosslinked system with some unreacted groups.

Figure 6.27. A schematic diagram of solid ground curing.

Figure 1. A schematic diagram showing casting and curing of the ultra low dielectric constant films. The fdms for devices are cast on silicon wafers.

Fig. 25. (a) Desmeared SAXS curves of PAA and PMDA-ODA polyimide films cured off substrate under different eonditions (1) 90°C/3.5 h + 150°C/8 h + 190°C/4 h + 240°C/5.5 h stepwise (2) 250°C/12 h (3) 350°C/12 h and (4) 430°C/2 h. (b) Schematic diagram of a possible layered morphology based on one-dimensional model analysis. Reprodueed with permission from J Polymer Sci, Polym Phys Ed 1981 19 1293. 1981 John Wiley Sons [72]. (c) Smeared SAXS eurves of PMDA-ODA polyimide films cured off substrate under different temperatures. Reproduced with permission from J Polymer Sci, Polym Phys Ed 1984 22 1105. 1984 John Wiley Sons [73]. 

If hexane is used as the low molecular weight liquid, the desired phase separation is observed when precursor mixtures containing 6-15 wt % hexane are cured isothermally at 40 °C. Further discussion of the phase separation behavior requires more detailed consideration of the schematic phase diagram, as presented in Fig. 17, which resembles the real phase diagram shown in Fig. 13. Experimentally it is found, that no phase separation occurs with hexane concentrations equal to or lower than 5 wt %. Hence the critical amount for phase separation, (j)p, is given by the intercept of the binodal line and the imaginary value of Hence no phase separation occurs if is reached before the metastable region is entered. 

Fig. 17. Schematic phase diagram explaining the phase separation behavior observed during the curing of epoxies in the presence of hexane...

The process of phase separation during cure arises from the change in the phase diagram as the cure reaction of the epoxy resin progresses. This is shown schematically in Figure 1.34 (Pascault et al, 2002) for a system with an upper critical solution temperature (UCST) in which the lower curve represents the system miscible at room temperature, with the fraction cpRo of elastomer corresponding to the initial composition of the rubber-epoxyresin system before any cure reaction has taken place. 

Figure 2.29. Schematic TXT cure diagram for a thermosetting system. The gelation and vitrification lines divide the liquid, rubbery and glassy state. Tgo, and Tgoo are the glass transition temperatures of the uncured and fully-cured resin, respectively gei Tg is the temperature at which gelation coincides with vitrification.

Fig. 8.20 (a) Phase diagram of epoxy oligomer/PES system, (b) Schematic representation of the variation of the phase diagram and Tg with curing. Solid circle ( ) represents curing condition... 

The curing of thermoset polymeric materials can be represented in terms of a time/temperature/transformation cure diagram, as schematically represented in Figure 5.1. In the cure diagram the times to gelations, induction time, maximum polymerisation degree and vitrification are plotted versus cure temperature [22, 23]. 

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