Mixing comparison with blending

NC(13.15% N) 87, DNT 10 DBuPh 3%. At about the same time, the proplnt called FNH (Flashless-Nonhygroscopic) was developed. Its compn was NC(12.6% N) 74, NC(13.25% N ), 20, DNT 5 DPhA 1%. Designations NH and FNH are not used any more, being replaced by letters M or T followed by numbers 1,2,3 etc(See Tables V,VI VII). M means a proplnt adopted for service and T, one in the experimental stage Current US Single-Base Cannon Propellants. In Table V there are listed only three proplnts (MIAI, M3D M31) which are based on "Pyrocellulose (NC with 12.6%N), because the majority of proplnts are now based on "Blend (NC 13.15-13.25%N), which is prepd by mixing "Pyro (12.6%N) with Guncotton (13.4-13.45%N). The 1st component is sol in 2 l-eth-alc, while the 2nd is not. Cannon proplnts Ml, M6, Ml4 and recoilless gun proplnt M10 are based on NC with 13.25%N and so are small arms proplnts IMR (Improved Military Rifle) and M12 (listed here for comparison with cannon proplnts)... 

Figure 5.6 Wide-angle neutron scattering profiles measured at the various temperatures for (c) DHDPE/LLDPE(2) and (d) DHDPE/LLDPE(3) blend samples in comparison with the profiles of (a) the amorphous state and (b) the crystalline state calculated for the pure DHDPE and the blend of D and H chain components. In (c), the low angle broad scattering is detected at any temperature due to the homogeneous mixing of D and H species in the same crystallite state as well as in the melt state. In (d), the low angle scattering can be seen only in the molten state, while it becomes lower when the sample crystallizes into the separated phases of D and H chains. These observations are consistent with the simulated results of (a) and (b).

The modification of bitumen with SBS copolymer powder was done using the mechanochemically devuicanized GRT (Zhu et al., 2009). The penetration index, softening point, 5°C ductility, aging behavior, and rheological properties of bitumens modified by 8,10, and 12 wt.% GRT/SBS mixtures were measured. In comparison with the bitumen modified by incorporation of 5.5 wt.% SBS alone, the majority of properties of the blends were improved, except their penetration. Rheological properties indicated that at high temperatures 10 wt.% GRT/SBS-modified bitumen was better than SBS-modifled bitumen. The SEM observation of the fractured surfaces showed that bitumens mixed with the GRT/SBS powder had a better interfacial adhesion with matrix than with SBS alone. 

The blended composites made of poly-L-lactic acid (PLLA)/poly-DL-lactic acid (PDLLA) and PLLA/PCL were compared for their mechanical properties [73]. In comparison with PLLA/PDLLA composites, PLLA/PCL composites have weaker mechanical properties, such as elastic modulus, yield strength, and ultimate strength. One approach of preparing these composites involves the use of methylene chloride solutions [73]. The mixed solution of PLA, PLLA, and PDLLA was poured into Teflon trays for vaporization of solvent. The composite laminates can be manufactured using the compression molding technique. 

Mixtures, formulated blends, or copolymers usually provide distinctive pyrolysis fragments that enable qualitative and quantitative analysis of the components to be undertaken, e.g., natural rubber (isoprene, dipentene), butadiene rubber (butadiene, vinylcyclo-hexene), styrene-butadiene rubber (butadiene, vinyl-cyclohexene, styrene). Pyrolyses are performed at a temperature that maximizes the production of a characteristic fragment, perhaps following stepped pyrolysis for unknown samples, and components are quantified by comparison with a calibration graph from pure standards. Different yields of products from mixed homopolymers and from copolymers of similar constitution may be found owing to different thermal stabilities. Appropriate copolymers should thus be used as standards and mass balance should be assessed to allow for nonvolatile additives. The amount of polymer within a matrix (e.g., 0.5%... 

PA-6/EPDM-f-epoxide Melt mixing/morphology/comparison to blend with unfimctionalized EPDM Wang et al. 1998b... 

Supri and Ismail [46] prepared modified and unmodified low-density polyethylene (LDPE) and mixed it with water hyacinth fiber (WHF) composites by melt blending. Tensile test, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and water absorption behavior test of the composites were conducted. The NCO-polyol-modified LDPE/AAfHF showed higher tensile strength, modulus of elasticity, and water absorption resistance as compared to the unmodified LDPE/WHF composites. However, the elongation at break was better when the LDPE was immodi-fied. Moreover, the modified LDPE/WHF offered better thermal properties in comparison to the unmodified LDPE/WHF. The NCO-polyol was reported to create better dispersion of WHF in the LDPE matrix. 

Figures 57 and 58 show the strength development of the two stabilised soils at 7 and 28 days. The stabilised soil with 60% of binder incorporating ROSA (Binder-B) showed the highest strength (Figure 57), revealing the potential of ROSA for use in soil stabilisation. The mix with 50% by weight of Binder-A performed satisfactorily according to TRL recommendations. Comparison with the compressive strength of stabilised soil with no binder reveals the beneficial effect of the novel blended binders in stabilising these two types of soil.

The mixing torque and apparent shear viscosity of the blends increased with increasing amounts of NR might be due to the natural characteristics of ADS that is produced from NR latex without shear cutting in the production process and it was dried at low temperature using the heat from sunshine. Therefore, ADS itself will have high Mooney viscosity in comparison with those other NR block types. 

Figure 18.42 showed characteristic torque values of binary polyamide 6/NR in comparison with polyamide 6/(NR with 3% w/w MA) blends obtained after 6 min of mixing. It was clear that MA-containing blends had much higher melt viscosity than polyamide 6/NR blends. It was assumed that these higher torque values were due to the occurrence of polyamide 6/NR grafting and also rubber crosslinking. 

The mixing behavior of two diblock copolymers with different relative composition has been treated theoretically. Sakurai and Nomura analyzed the phase behavior of diblock mixtures using the random phase approximation. They found the disordered phase to be suppressed in mixed diblock blends and a tendency to macrophase separation for such blends when the composition of the involved blocks becomes very asymmetric. They conclude that there are limitations in the comparison between blends of diblock copolymers with a diblock copolymer having the same overall composition, since the x -parameter determined for the blend may differ from the one determined... 

However, the of the PVOH component was lowered by increasing the amount of starch in the blend. Whilst this depression of the of PVOH is an indication of mixing, the fact that no averaging takes place between the of PVOH and starch is a sign that their miscibility is limited, most likely to local regions such as interfaces. It should also be noted that the intrinsic relaxation time of the starch component in the blends is shorter in comparison with values in unblended PIS, indicating that the molecular mobilities of the starch are also... 

Figure 5-19 shows an example of the dispersion of a chemical tracer in a stirred tank. A standard pitched blade turbine is used to mix two waterlike materials. The neutrally buoyant tracer is injected at time zero as a blob above the impeller, as shown on the top left in the figure. The flow field is calculated using the sliding mesh and LES models, and the dispersion of the tracer is derived from the flow field. The blob is stretched and the chemical is mixed with the rest of the fluid over time. It is interesting to see that despite the fact that there are four impeller blades and four baffles, the concentration field is not symmetric because of the off-axis injection. The consequence is that the full tank needs to be modeled instead of a 90° section. Bakker and Fasano (1993b) presented a successful comparison between blend time predicted by CFD and calculated from experimental correlations. 

Comparison with Mechanical Blenders or Homogenizers. Mechanical blenders normally have recirculation systems either within the blender or placed outside it. There are several types, but they have in common steep hopper half-angles with respect to vertical as compared to fluid bed blenders. This is required to allow all the mixed material to flow out of the blender. The silo geometry has to ensure mass flow conditions, which accounts for even withdraw of products, but at the same time, the angles have to be somewhat shallower to allow shear between the flowing layers of products to cause blending. If the outer hoppers are shallower, then normally, blenders are equipped with inserts, such as hopper-in-hopper types. These inserts can work in both axisymmetric and plane flow blenders, although the former types are more common. 

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