Sizing Specific melt viscosity

A wide range of physical constants, for instance melting point, boiling point, specific gravity, viscosity, refractive index, solubility, polymorphic forms vis-a-vis particle size, in addition to characteristic absorption features and optical rotation play a vital role in characterization of pharmaceutical chemicals and drug substances. These physical constants will be discussed briefly with typical examples as under ... 

The specific surface area of an industrial-sized continuous stirred tank reactor (CSTR) can be calculated from the reactor dimensions. However, it is difficult to estimate the effect of the formation of bubbles and of the stirrer-induced vortex at low melt viscosity. The calculation of the characteristic length of diffusion in a high-viscosity finishing reactor with devices for the generation of thin films with respective high specific surface areas is more complex. 

Despite the relative simplicity of most ionomers, questions about them remain. One of the key questions is how structure and dynamics on different length scales connect. Specifically, how does the metal coordination to the neutralized acid groups (which is on an angstrom level) correlate with the size, shape, and distribution of the ion-iich aggregates in the hydrophobic matrix (which is on a nanometer length scale) Furthermore, how does the microscopic structure control the macroscopic properties like melt viscosity or elastic modulus ... 

Melt Index A single point identification of resin melt viscosity, measured in grams per 10 minute period passing through a specific orifice size at a cenain temperature, as dictated by test method ASTM D1238. 

Physical characteristics Molecular weight Vapour density Specific gravity Melting point Boiling point Solubility/miscibility with water Viscosity Particle size size distribution Eoaming/emulsification characteristics Critical temperature/pressure Expansion coefficient Surface tension Joule-Thompson effect Caking properties... 

The physical properties of a substance are dependent on the nature of the atoms found in it and the type of bonds between them. The size and shape of the molecules from which a substance is composed determine the aggregate state and all related specific properties like melting point, vapor pressure, density, viscosity and solubility in various media. This also includes the number value of the partition coefficient. Funda-... 

There have been some efforts in slurry recycling to reduce CoO of CMP consumables. In a recent study [37], the effluent samples were characterized for pH, trace-metal levels, viscosity, specific gravity, mean aggregate particle size, and LPC (>1.0 rm) before and after depth (melt-blown polymeric media) filtration. The study showed that the use of a recycled fumed silica slurry (recycled five times) decreased the CMP removal rate and the coefficient of friction (COF) by 40%. A perfect relationship was observed between the removal rate and COF. It was concluded that the increase in mean aggregate particle size, which lowers the contact area between the abrasive particles and the wafer, had some impact on the removal rate data. In general, there is a stronger emphasis on slurry additives and chemical action in current CMP processing with much lower maximum defectivity performance specifications [2]. 

The performance of an extruder is determined as much by the characteristics of the feedstock as it is by the machine. Feedstock properties that affect the extrusion process inciude buik properties, meit flow properties, and thermal properties. Important buik flow properties are the buik density, compressibility, particle size, particle shape, external and internal coefficient of friction, and agglomeration tendency. Important melt flow properties are the shear and eiongational viscosity as a function of strain rate and temperature. The commonly used melt indexer provides only limited information on the meit viscosity. Important thermal properties include the specific heat, the glass transition temperature, the crystalline melting point, the latent heat of fusion, the thermal conductivity, the density, the degradation temperature, and the induction time as a function of temperature. 

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