Rheology thermo

Properties of carbon-epoxy composites are dependent on the chemical and rheological events occurring during the epoxy cure cycle (1,2) The ability to conduct continuous in situ measurements of the epoxy cure states, cure kinetics, and viscosity of the resin matrix would enhance control of composite structures. Rheological, thermo-analytical, and spectroscopic techniques that measure these variables exist and are frequently used in laboratory studies of epoxy cure behavior. Physical restrictions, however, prevent the application of such techniques for in situ measurements during autoclave curing of composite structures in the factory setting. 

Among the adaptive materials currently on the forefront are liquid crystals, electro- and magneto-rheological (ER/MR) fluids, thermo- and physioreponsive gels, and shape memory alloys. In all but the last case, these systems involve... 

To enhance the usefulness of the Second Edition for both students and practitioners of the field, an extensive Appendix of rheological and thermo-mechanical properties of commercial polymers, prepared and assembled by Dr. Victor Tan, and for teachers, a complete problem Solution Manual, prepared by Dr. Dongyun Ren are included. For all it is hoped that this Second Edition, like the First, proves to be a useful professional companion . 

Detailed analysis of the isothermal dynamic mechanical data obtained as a function of frequency on the Rheometrics apparatus lends strong support to the tentative conclusions outlined above. It is important to note that heterophase (21) polymer systems are now known to be thermo-rheologically complex (22,23,24,25), resulting in the inapplicability of traditional time-temperature superposition (26) to isothermal sets of viscoelastic data limitations on the time or frequency range of the data may lead to the appearance of successful superposition in some ranges of temperature (25), but the approximate shift factors (26) thus obtained show clearly the transfer viscoelastic response... 

The model fluid food studied was 3.5% com SDs whose thermo-rheological properties were described by the model developed by Yang and Rao (1998a) ... 

The effect of different flow properties on heat transfer to canned dispersions undergoing intermittent axial rotation was studied by Tattiyakul et al. (2002b). In addition to the 3.5% cornstarch dispersion discussed above, a 5% CWM dispersion whose rheological data are shown in Figure 8-9 and a tomato concentrate that followed a simpler thermo-rheological behavior were studied. Because of the high apparent viscosity over a wide temperature range of the CWM dispersion, it had the slowest time-temperature profile (not shown here). Results on the effect of continuous axial rotation on heat transfer to a canned starch dispersion can be found in Tattiyakul (2001). 

Tattiyakul, J., Rao, M. A., and Datta, A. K. 2002b. Heat transfer to three canned fluids of different thermo-rheological behavior under intermittent agitation. IChemE Trans. Part C-—Food and Bioproducts Process 80 20-27. 

However, the fact that superposition applies to G and G" does not necessarily imply that the systems behave as single phase systems since it has been shown (22-23) that two-phase blends can act as thermo-rheologically simple materials for polymer blends consisting of polymers of high polydisperslty, although we believe that this Is a relatively rare case. 

Samakande A, Sanderson RD, Hartmann PC (2009) Rheological properties of RAFT-mediated poly(styrene-co-butyl acrylate)-clay nanocomposites [P(S-co-BA)-PCNs] emphasis on the effect of structural parameters on thermo-mechanical and melt flow behaviors. 

Test of time-temperature superposabillty for the dielectric P data of low-M and middle-M poly-isoprene/poly(p-feri butyl styrene) (PI/PtBS) miscible blends as indicated. In panels (a)-(d), the sample code numbers of the blends denote Kh M of the components. The reference temperature is T, = 90°C for aU blends. The solid curves indicate the e" data of bulk PI corrected for the PI volume fraction in the blends. These curves are shifted along the axis to match their peak frequency with that of the blends. (Etata taken, with permission, from Chen, Q., Y. Matsumiya, Y. Masubuchi, H. Watanabe, and T. Inoue. 2008. Component dynamics in polyisoprene/ poly(4-tert-butylstyrene) miscible blends. MacrvmoJeades 41 8694-8711 Chen, Q., Y. Matsumiya, Y. Masubuchi, H. Watanabe, and T. Inoue. 2011. Dynamics of polyisoprene-poly(p-tert-butylstyrene) diblock copolymer in disordered state. Macnmiolecules 44 1585-1602 Chen, Q., Y. Matsumiya, K. Hiramoto, and H. Watanabe. 2012. Dynamics in miscible blends of polyisoprene and poly(p-terf-butyl styrene) Thermo-rheological behavior of components. Polymer ]. 44102-114.)... 

Chen, Q., Y. Matsumiya, K. Hiramoto, and H. Watanabe. 2012. Dynamics in miscible blends of polyisoprene and poly(p-tert-butyl styrene) Thermo-rheological behavior of components. Polymer. 44 102-114. 

Verber R, Blanazs A, Armes SP (2012) Rheological studies of thermo-responsive dibiock copolymer worm gels. Soft Matter 8 9915-9922... 

Men Y, Rieger J, Strobl G (2003b) Role of the entangled amorphous network in tensile deformation of semicrystalline polymers. Phys Rev Lett 91 955021-955024 Men Y, Strobl G (2002) Evidence for a mechanically active high temperature relaxation process in syndiotactic polypropylene. Polymer 43 2761-2768 Plazek DJ, Chay I, Ngai KL, Roland CM (1995) Visoelastic properties of polymers. 4. Thermo-rheological complexity of the softening dispersion in polyisobutylene. Macromolecules 28 6432-6436... 

In conclusion, these HTP solutions are distinguished by a thermo-rheological simplicity as well as by a secondary relaxation which is undoubtfully characteristic of the multiplets formed by the metal carboxylate end-groups. These features largely justify the choice of HTP as model compounds for ion-containing polymers. Furthermore, the rheological behavior, and more especially the shear-thickenii effect, impart to HTP solutions an important technological interest. 

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