Poly rheological behavior

Oommen, Z., S. Thomas, C. K. Premalatha, and B. Kuriakose, Melt rheological behavior of natural rubber/polyfmethyl methacrylate)/natural rubber-g-poly(methy methacrylate) blends. Polymer, 38(22), 5611-5621 (1997). 

Fig. 18. The steady-shear rheological behavior for a series of intercalated nanocomposites of poly(dimethyl0 95-diphenyl0 05siloxane) with layered silicate (dimethyl ditallow montmo-rillonite) at 25 °C. The silicate loading is varied and are noted in the legend. From Ref. [5].

Poly(methylmethacrylate), PMMA, latex particles have also served as a model colloidal system for many years (mainly as hard spheres with hydroxy stearic acid (HSA) chains being the grafting choice [91,113,114]). Tunability was achieved by varying the core size and the size of the corona chains. The comparison between chemically grafted (stable) and end-adsorbed temperature-sensitive chains (usually surfactants) has shown that the adsorbed chain particles exhibit similar rheological behavior with chemically grafted particles [115]. 

The above references mainly describe rheological behavior of graphite fiber (length 0.5-16 cm) in poly-ether-ketone-ketone (PEKK) at 370°C. Anthors conclnde that the transient and steady-state rheological properties of these materials are different from the unfilled melt. 

This chapter is an in-depth review on rheology of suspensions. The area covered includes steady shear viscosity, apparent yield stress, viscoelastic behavior, and compression yield stress. The suspensions have been classified by groups hard sphere, soft sphere, monodis-perse, poly disperse, flocculated, and stable systems. The particle shape effects are also discussed. The steady shear rheological behaviors discussed include low- and high-shear limit viscosity, shear thinning, shear thickening, and discontinuity. The steady shear rheology of ternary systems (i.e., oil-water-solid) is also discussed. 

Effects of addition of a compatibilizing block copolymer, poly(styrene-b-methyl methacrylate), P(S-b-MMA) on the rheological behavior of an immiscible blend of PS with SAN were studied by dynamic mechanical spectroscopy [Gleisner et al., 1994]. Upon addition of the compatibilizer, the average diameter of PS particles decreased from d = 400 to 120 nm. The data were analyzed using weighted relaxation-time spectra. A modified emulsion model, originally proposed by Choi and Schowalter [1975], made it possible to correlate the particle size and the interfacial tension coefficient with the compatibilizer concentration. It was reported that the particle size reduction and the reduction of occur at different block-copolymer concentrations. 

The concentration dependence of the Brookfield viscosity (Figures 9 and 10) indicates a rapid drop in viscosity upon dilution below a critical concentration. Bagley (7) attributed such rheological behavior to a structure of swollen, deformable gel particles closely packed in intimate contact. Davidson (8) later attributed the thickening efficiency of a cross-linked poly(acrylic acid) to the dispersed rather than the continuous phase. In general, pseudoplastic and viscoplastic rheology is characteristic of dispersions with low... 

Polymer-surfactant interactions are the basis for the rheological behavior of MHAPs. Other surfactant-polymer systems have previously been investigated. One example is the interaction of surfactants with polymers such as poly(ethylene oxide), which results in greater solution viscosities than with the polymer alone (e.g., ref. 25 and references therein). The interaction of surfactants or latexes with hydrophobically modified water-soluble polymers has also been shown to produce unique rheology (2, 5, 26, 27). In these systems, the latex particles or the surfactant micelles serve as reversible cross-link points with a hydrophobic region of a polymer molecule in dynamic association with a latex particle or surfactant micelle (27). 

Lee et al. [2007] studied the rheological behavior of poly(ethylene-co-vinyl acetate) (EVAc 40 wt% VAc) and its CPNC with < 10 wt% C30B the tests were conducted under steady-state and small oscillatory shear flow. The samples were prepared by melt compounding at 110 C for 25 min, which resulted in a high degree of dispersion. The flow behavior was quite regular, well described by the Carreau-Yasuda equation [Carreau, 1968,1972 Yasuda, 1979] ... 

The stability of any emulsion is largely due to the nature of the film that is formed between two approaching droplets. Coalescence of drops in any emulsion system is a dynamic process. The rheological behavior of emulsions depends on the response of the thin liquid films and the plateau borders during shear and dilation. In real emulsions, the size and distribution of the drops is generally poly disperse. Hence,... 

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. 

Kunieda s group reported numerous viscoelastic worm-like micellar systems in the salt-free condition when a lipophilic nonionic surfactant such as short hydrophilic chain poly(oxyethylene) alkyl ether, C EOni, or N-hydroxyethyl-N-methylaUcanolamide, NMEA-n, was added to the dilute micellar solution of hydrophilic cationic (dodecyltrimethylammonium bromide, DTAB and hexade-cyltrimethylammonium bromide, CTAB) [12-14], anionic (sodium dodecyl sulfate, SDS [15, 16], sodium dodecyl trioxyethylene sulfate, SDES [17], and Gemini-type [18]) or nonionic (sucrose alkanoates, C SE [9, 19], polyoxyethylene cholesteryl ethers, ChEO [10, 20], polyoxyethylene phytosterol, PhyEO [11, 21] and polyoxyethylene sorbitan monooleate, Tween-80 [22]) surfactants. The mechanism of formation of these worm-Hke stmctures and the resulting rheological behavior of micellar solutions is discussed in this section based in some actual published and unpublished results, but conclusions can qualitatively be extended to aU the systems studied by Kunieda s group. 

Acharya, D.P., Sato,T., Kaneko.M., Singh, Y., and Kunieda, H. (2006) Effect of added poly(oxyethylene)dodecyl ether on the phase and rheological behavior of wormlike micelles in aqueous SDS solutions./. Phys. Chem. B, 110,754-760. 

While the Choi and Schowalter [113] theory is fundamental in understanding the rheological behavior of Newtonian emulsions under steady-state flow, the Palierne equation [126], Eq. (2.23), and its numerous modifleations is the preferred model for the dynamic behavior of viscoelastic liquids under small oscillatory deformation. Thus, the linear viscoelastic behavior of such blends as PS with PMMA, PDMS with PEG, and PS with PEMA (poly(ethyl methacrylate))at <0.15 followed Palierne s equation [129]. From the single model parameter, R = R/vu, the extracted interfacial tension coefficient was in good agreement with the value measured directly. However, the theory (developed for dilute emulsions) fails at concentrations above the percolation limit, 0 > (p rc 0.19 0.09. 

Green, D. L. Mewis, J., Connecting the Wetting and Rheological Behaviors of Poly(dimethylsiloxane)-Grafted Silica Spheres in Poly(dimethylsiloxane)... 

Poly(vinyl chloride) (PVC) is a commercially important polymer. Rheological behavior of PVC is very important in processing. The process of PVC gelation is affected by additives. The investigation of rheological properties of the formulations is important for PVC processing. It is important... 

Kim Jin Kon, Han Chang Dae, and Lee Young Ju. Rheological behavior of miscible blends of polystyrene and poly(2,6-dimethyl-l,4-phenylene ether). Polym. J. 24 (1992) 205-213. 

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