Physical and rheological properties

The flow of compressible and non-compressible liquids, gases, vapors, suspensions, slurries and many other fluid systems has received sufficient study to allow definite evaluation of conditions for a variety of process situations for Newtonian fluids. For the non-Newtonian fluids, considerable data is available. However, its correlation is not as broad in application, due to the significant influence of physical and rheological properties. This presentation is limited to Newtonian systems, except where noted. 

Haug I.J., Draget K.I., Smidsr0d O. 2004. Physical and rheological properties of fish gelatin compared to mammalian gelatin. Food Hydrocolloids 18, 203-213. 

Chaisawang, M., Suphantharika, M. (2005). Effect of guar gum and xanthan gum additions on physical and rheological properties of cationic tapioca starch. Carbohydr. Polym., 61,288-295. 

TABLE I. Selected Physical and Rheological Properties of Extrusion Texturized Soy... 

Modification of the Properties of Fats and Oiis Transesterification reactions (interesterification and acidolysis) of triacylglycerols have been an important tool in fats and oils processing for the modification of their physical and rheological properties by changing the composition and distribution of their fatty acids. 

Munoz-Ruiz A, Monedero Perales MC, Velasco Antequera MV, Jimenez-Castellanos MR. Physical and rheological properties of raw materials. STP Pharma (Set) 1993 3 307-312. 

The variations of the physical and rheological properties of the material with the reaction are described by constitutive equations. In particular, changes in viscosity with reaction extent can encompass several orders of magnitude, so it is important to establish adequate rheoldnetic relationships. 

The random nature of the recycling system can lead to extreme lot to lot variation in batches of reclaimed material. If the life cycle described earlier is repeated a number of times, it can be shown that the variability in the source material for recycling will increase dramatically. This puts tremendous pressure on the recycler to maintain consistency. It has been shown that, while lots of reclaimed material may have average physical and rheological properties close to the virgin polymer, their consistency is unpredictable [18]. The presence of contaminants produced numerous extrusion, odor and smoke problems. 

As mentioned, a lot of theoretical and experimental studies have been performed to understand physics and rheological properties of lyotropic LCPs. The molecular Doi approach with many improvements and experimental tests is well presented in the literature (e.g., see Ref. [5]). But the thermotropic LCPs were poorly understood till recently, in spite of many attempts to develop either nematodynamic or molecular description of their flow properties. The beauty of continuum approach is that it can be applied to molecular nematics ofboth different types, as well as to the nonyielding suspensions with shaped particles. Yet, general nematodynamic theories are multi-parametric. For example, the general LEP continuum LC theory contains five constitutive parameters [2]. Similarly, de Gennes potential proposed for the monodomain description of general weakly elastic behavior of LCE has also five parameters [37]. Because viscoelasticity is a combination of elastic and viscous effects, it is expected that even in easy theoretical schemes, the continuum approach to viscoelastic polymer nematodynamics should involve at least 10 constitutive parameters. 

Nevertheless, little work has been published on the physical properties of interesterified blends. In this research, we reported on the melting, crystallization, rheological, and crystal properties of butterfat and butterfat-canola oil blends following interesterification with an OT-l,3-specific lipase from Rhizopus arrhizus as a means of understanding the physical and rheological properties of fats. Furthermore, the complex relationship between composition, rheology, and microstructure could be further clarified. 

Futamura S, Meinecke E (1977) Effect of center block structure on the physical and rheological properties of ABA block copolymers. Part II. Rheological properties. Polym Eng Sci... 

The influence of mesomorphic polymer components on the morphological, physical, and rheological properties of blends with polyester, polyamide, polycarbonate, and polyolefin matrix has been investigated in several cases [115]. Studies on blends of PET, PBT, PC, PS with main chain liquid crystal polymers and copolymers of various type (including flexible LC copolyesters and wholly aromatic LC copolyesters) showed that the phase transitions and properties were largely dependent on the chemical structure, molar mass, processing conditions, and concentration of components [132-134]. Generally, these systems displayed phase separation in the molten... 

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