Blending indices determination

In general, the multiphasic heterogenous nature of the impact grade styrene-based polymers is the root cause of their opaque-turbid nature. In determining the transparency of the blends, size and the size-distribution pattern of the dispersed phase along with the refractive index difference between the continuous and the dispersed phases are two very important criterion [133]. 

LCO is highly aromatic (50 wt% to 75 wt%) and has a low cetane index (20-30). The cetane number and sulfur content determine the amount of LCO that can be blended into the diesel or heating oil pool. 

To support this hypothesis, the OBC sample can be fractionated by the TREF experiment. TREF fractionation of the OBC, followed by evaluation of the octene content by 13C NMR, reveals the data shown in Fig. 21. For a polymer blend, each molecule dissolves and elutes according to its comonomer content. The results invariably fall on the line in Fig. 21 labeled random copolymer line. The triangles reveal the comonomer content of the TREF fractions from an OBC. At any given temperature, the polymer eluting has much more comonomer than would be expected for a random distribution. The only explanation is that the comonomer is blocked, as expected from the chain shuttling mechanism. The extent of deviation can even be quantified, and a new method was recently invented to determine the block index for a given polyolefin [46],... 

Glass transition temperature is one of the most important parameters used to determine the application scope of a polymeric material. Properties of PVDF such as modulus, thermal expansion coefficient, dielectric constant and loss, heat capacity, refractive index, and hardness change drastically helow and above the glass transition temperature. A compatible polymer blend has properties intermediate between those of its constituents. The change of glass transition temperature has been a widely used method to study the compatibility of polymer blends. Normally, the glass transition temperatme of a compatible polymer blend can be predicted by the Gordon-Taylor relation ... 

Protein dispersibility index Dry product is dispersed in water by blending, then centrifuged at 880 x g for I0 min Protein dispersibility index (%) = (% water-dispersible prolein/% total protein) x 100 Advantages Tested in a collaborative study and found to be reproducible between laboratories. Disadvantages Limited to soy products protein is determined by Kjeldahl analysis, which can be a lengthy procedure. AOCS Method B a 10-65 (AOCS, 1999) AACC Method 46-24 (AACC, 2000)... 

In another test method (ASTM D-5515), a dilatometer is used to measure the swelling of bituminous coal. The test method is limited in applicability to coal that has a free swelling index < 1 (ASTM D-720). The principle of this test method is that the final volume of char obtained at the conclusion of a standard dilatation test is dependent on the mass of coal in the coal pencil and on the radius of the retort tube. This test method incorporates a procedure that determines the mass of air-dried coal in the coal pencil, provides a means to measure the average retort tube radii and employs a means to report coal expansion on an air-dried coal weight basis. The value of the dilatation properties of coals may be used to predict or explain the behavior of a coal or blends during carbonization or in other processes, such as gasification and combustion. 

The two sets of computations - forward scatter and side scatter - are made separately. In order to determine the complete size distribution, the forward and side scatter determinations must be combined. This is accomplished by adjusting the gain on the side scatter computations until those channels blend together with the distribution—incorporating both forward and side scatter distributions—is then renormalized and printed out as a l6-channel particle size distribution from 0.12 to 1 2.2 microns. Any Mie constant adjustment is made to the forward scatter computations alone because the side scatter channels are relatively insensitive to variations in the refractive index. 

The density of fats and oils is an index of the weight of a measured volume of the material. This property is important not only for designing of equipment but also for the estimation of the solid fat index (SFI). The SFI is related, approximately, to the percentage of solids in a fat at a given temperature. When determined at a number of specified temperatures, it can be especially useful to margarine manufacturers or other processors who need to control the characteristics of their manufactured products by blending. 

Physical Characteristics. The proper blend of basestocks and hardstocks must be identified that provide the physical, functional, and organolepic properties required by the finished product. These characteristics are usually identified analytically with solids fat index, melting point, and iodine value determinations. 

The Gyna-ir Correlation can be sharpened by the two-phase argument. With the crosslinking agents confined to their own phase, the quantity of gel should be determined by the total surface area of that phase and, hence, the dispersion of the E/ABP in the polyethylene matrix. If we assume that better blending is achieved by matching the component melt viscosities, then Qninv should be dependent on the sensitizer melt index (MI), the relative volumes of the components -blend ratio, BR - and the total sensitizer concentration (Co). From least squares analyses of our results, we find ... 

Flash points calculated by the proposed sum-of-indexes method are compared in Table III with experimentally determined flash points. To place this comparison in context, Table III also includes several other comparisons between sets of data. When earlier experimentally determined data were compared with flash points redetermined for this study, the differences were almost evenly distributed around the zero point. The median absolute difference between the two sets of data was 5°F while the largest difference between flash points determined for a single blend was 27°F. Some skew is apparent in the differences between either set of experimental data and the calculated flash points. The median absolute differences between experimental and calculated data were either 7° or 8°F depending upon which set of experimental data was used in the comparison. When the flash point of the lowest flashing component was taken as an indication of blend flash point, the median differences from the two sets of experimental data were 13° and 18 °F, respectively. 

One method is based on determining the refractive indexes of the two phases by interference microscopy. However this technique, which gives semi-quantative information, can be applied only if the particles of the dispersed phase are not too small (I, 2). We therefore prepared by anionic polymerization different copolymers of PS-PI containing a fluorescent group like styrene-9-phenyl-10-anthracene (see Structure 7 for structure of fluorescent copolymers). In such a PS-PI blend, the PI phase can be detected first by phase... 

Optical properties of blends have been studied to determine the factors leading to turbidity and hence to the design of blends with superior appearance. The analysis of the scattering of light and X-ray provides information about the morphology of the blends, allowing to measure the size and shape of the domain, as well as the differences in refractive index or electron density between components. 

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