Product properties dispersity

Natural product-derived dispersants, such as tannins, lignins, and alginates, are still widely used as drilling mud thinners or in specialty applications where their low toxicity is a cmcial property, eg, in boilers producing steam for food applications. 

In this chapter, the polymerization methods used for the production of uniform latex particles in the size range of O.I-lOO /Ltm are described. Emulsion, swollen emulsion, and dispersion polymerization techniques and their modified forms for producing plain, functionalized, or porous uniform latex particles are reviewed. The general mechanisms and the kinetics of the polymerization methods, the developed synthesis procedures, the effect of process variables, and the product properties are discussed. 

The production of substances with well-defined product properties under consideration of economical and ecological boundary conditions is the objective of many processes. For particulate materials, the product properties depend not only on the chemical composition but also on the dispersity of the material. The dispersity is characterized by the particle size distribution, the particles shape and morphology as well as their interfacial properties. This relation was called property function by Rumpf [1]. The control of the property function is known as product engineering or product design. 

Crystal morphology (i.e., both form and shape) affects crystal appearance solid-liquid separations such as filtration and centrifugation product-handling characteristics such as dust formation, agglomeration, breakage, and washing and product properties such as bulk density, dissolution kinetics, catalytic activity, dispersability, and caking. 

The initial form of the filler is another complicating factor. Good and consistent dispersion of filler contributes to product properties. There two goals when filler is to be mixed ... 

The series of photographs shown in Fig. 9.2 depicts various views of support laboratories. Here, particle size distributions and, sometimes, specific surface area, moisture content, powder flowability, product strength (defined, for example, by crushing, drop, or abrasion) and density or porosity and other, more specific information, such as dispersibility, solubility, reactivity, are determined [B.97]. The results define the feed characteristics and check the product properties. Often data acquisition and computerized evaluation systems are part of these supporting laboratory facilities. 

Blending offers an interesting means of tailoring product properties to specific applications. However, in the case of immiscible polymer pairs, the desired properties are not achieved readily without a compatibilizer, which enhances the phase dispersion and stability, as well as a good adhesion between the phases. This can be effectuated by physical or reactive methods [Folkes and Hope, 1993]. Compatibilization strongly affects the blend phase morphology and as such, it also may influence the crystallization behavior of the blend [Flaris et al., 1993]. Because both factors are related to the final properties of the blend, it is worth paying attention to these phenomena. 

The nucleation, polymerization and growth, and preparation of monodisperse sols is a focal point of research for many reasons. The nature of our understanding and the ease of formation make the sHica system ideal for studying nucleation and growth of particles in a disperse state. SHica offers many diverse routes to similar products, allowing for customizing of product properties. 

Characteristics of polymer dispersions that influence product properties... 

Emnlsion polymerisation is influenced by system turbulence due to its heterogeneous nature. System effective agitation is necessary to keep the particles in dispersed phase, to prevent flocculation, to improve mass and heat transfer, phenomena that influence the reaction mechanism and kinetics as well as the final product properties and the properties of the product based on achieved latex. The influence of agitation on properties of the product using the obtained latex is presented, with emphasis on viscosity and rheological behaviour. Also presented is the influence of system initial rheology scaling up. 18 refs. 

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