Dispersion hardness

Z. Tang, L. E. Scriven, H. T. Davis. Size selectivity in adsorptions of poly-disperse hard-rod fluids in micropores. J Chem Phys 97 5732-5737, 1992. 

This characteristic, known as the dispersion hardness DH, indicates the effort that is necessary to disperse a pigment [94] ... 

Melt-processable polymer blend or copolymer in which a continuous elastomeric phase domain is reinforced by dispersed hard (glassy or crystalline) phase domains that act as junction points over a limited range of temperature, or... 

It would be reasonable to assume that all these mechanisms operate in real dispersion. Hard agglomerates, which are most damaging to the product, would most likely break by the rupture mechanism, while softer agglomerates may erode. 

DSC, WAXS, electron diffraction, and electron microscopy support a phase-separated morphology for all five of the random copolymer PCP/MDI/BDO-segmented polyurethanes studied. The slight increase observed by Seefried et al. (9) in the lower temperature Tg with hard-segment concentration is therefore likely attributable to increased reinforcement of the soft-segment matrix by an increased number of dispersed hard-segment domains. 

A copolymer of D2i-DiSiAn, BPADA, and mPD was prepared and examined by DMA. The DMA indicated a distinct transition at 120 corresponding to the siloxane block and a weaker transition at 75 corresponding to the imide hard block. This behavior is consistent with a phase-separated material with short, well-dispersed hard blocks. The physical properties of this copolymer are shown in the following list. The elastoplastic properties of the material are also consistent with this type of microstructure. 

Laminaria possesses remarkable properties that make it a wonderful component of dietary supplements. Due to its amazing medicinal benefits, it has been used in traditional Chinese medicine since centuries and is listed in the Chinese pharmacopeia. In general. Laminaria is considered as a cold, salty herb, prescribed to cleanse heat, resolve phlegm, and soften and disperse hard accumulations (e.g., goiters). It is often used to control edema, as an expectorant and antitussive, and as a remedy for testicular pain and swelling. Despite its salty character, the herb is slightly hypotensive. 

The main properties are determined by the matrix (coherent soft phase) the disperse hard phase then shows the transformation. 

This means that dispersed hard 15-nm blocks should have diffusivities less than about 10 cm /s and 100-nm soft block matrix layers should have diffusivities in the order of 10 cm /s in order for application and reversible mechanism to occur in less than 1 s. This is reasonable for the soft block, since diffusivities for rubbery polymers can go up to 10 cm /s. However, glassy polymers can have diffusivities as low as 10 " cm /s. Thus, for diffusion times less than 1 s, these domains should have sizes less than 1 nm. This can be satisfied by a hydrophilic block made up of a random copolymer of a hydrophilic monomer and a comonomer with a... 

The effective pair interactions measured with these techniques are the direct pair interactions between two colloidal particles plus the interactions mediated by the depletants. In practice depletants are poly disperse, for which there are sometimes theoretical results available. For the interaction potential between hard spheres we quote references for the depletion interaction in the presence of polydisperse penetrable hard spheres [74], poly disperse ideal chains [75], poly-disperse hard spheres [76] and polydisperse thin rods [77]. 

Fig. 23. Dynamic mechanical properties of the segmented PU elastomer PU-4 with monodisperse (n=3, cf. formula in Fig. 3 (—)) and PU-4 with poly-disperse hard segment length distribution (POTM-28/MDI/BDO=1 4 3).

Figure 1.5 Definition of the connectedness criterion (Equation 1.2) and its contribution to the percolation threshold as defined for mono-disperse hard-core rods.

Hostapur DTC HI Cone, dispersant, hard-surfoce abrasives C12-15 pareth6 Cl 2-15 pareth-12 Teric G12A6 Teric G12A8 Teric G12A12 Teric LA8 dispersant, hard-surfoce cieaners AG 6202 AG 6206 Alcosperse 240 Alcosperse 602-N Amphoteen 24 ... 

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