Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Silica compounds compound composition

Table 8 Compound compositions for silica in the SBR/EPDM blend... Table 8 Compound compositions for silica in the SBR/EPDM blend...
Used particularly for paper, plastic and composite sacks. With paper sacks use a creped Kraft paper on the outside ply. Even with dusty materials this increases the coefficient of friction of the contact areas, thereby reducing the chances of unwanted movement of one sack over another. Other treatments of paper use colloidal silica or compounds containing alumina. [Pg.404]

Hydrophobic Silicas. Because foaming is a surface phenomenon, any antifoam used must concentrate at the surface (or gas—liquid interface). Hydrophobic silicas, which are silicas that have been treated with a compound that causes them to float on the top of water, have been used to fulfill this function for almost 30 years. U.S. Patent 3 408 306 (5) discloses the use of a hydrophobic silica dispersed in a hydrocarbon oil. Hydrophobic silica for this composition, which is still in use today, is made either by continuous ( dry roast ) or batch process. In either process, precipitated silicas rather than silica gels or fumed silicas are typically used to make antifoams. During a continuous process, silicone oils, usually poly(dimethylsiloxane), are sprayed onto a bed of hydrophilic silica. The bed is heated to temperatures ranging up to 300 °C, and reaction times are up to 20 h. At these temperatures and reaction times, bond formation between the silica particle and silicone oil may occur in addition to simple coating of the particle. [Pg.460]

The EPA uniquely addresses TSCA Inventory listings for silica compounds. Silicon dioxide (Si02 commonly known as silica ) is commercially distributed in several physical forms. Because the chemical compositions of the various physical forms of silica are identical, the EPA does not distinguish them for TSCA Inventory purposes. The EPA does not consider differences in toxicity between these various physical forms as requiring separate TSCA Inventory status. Such distinctions are made at the state level particularly for silica forms with a crystalline component. [Pg.50]

Chemically, BA and BS are composed principally of silica, aliunina, and iron, with smaller percentages of calcium, magnesium, sulfates, and other compounds. The composition of the BA or BS particles is controlled primarily by the source of the coal and not by the type of furnace. BA or BS derived from lignite or sub-bituminous coals have higher amounts of calcium than the BA or BS from anthracite or bituminous coals. Sulfate is usually very low (less than 1.0%), imless pyrites have not been removed from the coal fuels. [Pg.93]

The research results confirm that the application of silica-organic compounds for modification of cellulose fiber surface considerably improves strength properties of composites [50, 51, 72-75]. Raj et al. [72] found that the modification of cellulose fibers with silanes as well as with isocyanate caused improvement of mechanical properties of composites based on polypropylene matrix. However, studies conducted by Hornsby et al. [76] do not confirm that. His results prove that processing flax fibers with silanes has no effect on mechanical properties of composites based on polypropylene matrix. These contradictory conclusions are probably the effect of a complex anatomical structure of cellulose fiber and/or application of suitable conditions of modification reaction. [Pg.282]

Moreover Ponomarenko et al. reported the melt-compounded composites of synthetic styrene-co-butadiene mbber (BUNA SL18) and silica particles (Silica VN3, Degussa). They showed that at low elongations, silica particles provided a considerably weaker reinforcement effect of the mbber matrix when compared to organoclay nanoparticles. The overall tiiermoelastic behavior of both the mbber/ silica composites and the mbber/organoclay nanocomposites could be quantitatively... [Pg.179]

A summary is presented of the results of studies of the properties of silica filled compounds based on emulsion SBR prepared by blending high and low molecular weight polymers with different styrene-butadiene compositions. The mechanical and dynamic mechanical properties and extrusion characteristics were investigated and compared with those of solution SBR and conventional emulsion SBR. [Pg.87]

In situ assembly is also the preferred method used for obtaining polymer-encapsulated MOFs (Polymer MOF), prepared by pre-adsorbing suitable monomers inside the MOF pores followed by their in situ polymerization [31,33,57,58]. Also in this case, several precedents exist for the preparation of polymers encapsulated inside zeolites or mesoporous silica compounds [59-63]. Applications of such composites materials were long ago anticipated in the fields of electronic/ionic transport materials, optoelectronics, and sensor devices [64], and the emergence of MOFs as novel host materials will surely reactivate the interest in these composites (see for instance. Ref. [8]). [Pg.317]

Polypropylene and the PIB-grafted silicas were mixed in DSM Xploreminicompouder Mixer volume 15 cm, +210°C, 6 minutes. The compositions of the three PP-PIB-silica compounds are summarized in Table 1. [Pg.93]

Table l. The compositions of PP-PIB-silica compounds. The weight fraction of silica was kept... [Pg.93]

Take the silica-alumina system as an example. It is convenient to treat the components as the two pure oxides SiOj and AI2O3 (instead of the three elements Si, A1 and O). Then the phase diagram is particularly simple, as shown in Fig. 16.6. There is a compound, mullite, with the composition (Si02)2 (Al203)3, which is slightly more stable than the simple solid solution, so the alloys break up into mixtures of mullite and alumina, or mullite and silica. The phase diagram has two eutectics, but is otherwise straightforward. [Pg.173]


See other pages where Silica compounds compound composition is mentioned: [Pg.997]    [Pg.43]    [Pg.77]    [Pg.50]    [Pg.105]    [Pg.189]    [Pg.198]    [Pg.43]    [Pg.371]    [Pg.646]    [Pg.1247]    [Pg.161]    [Pg.809]    [Pg.237]    [Pg.565]    [Pg.586]    [Pg.588]    [Pg.9]    [Pg.892]    [Pg.2]    [Pg.3]    [Pg.325]    [Pg.285]    [Pg.67]    [Pg.1427]    [Pg.33]    [Pg.81]    [Pg.268]    [Pg.5]    [Pg.451]    [Pg.167]    [Pg.155]    [Pg.469]    [Pg.470]   
See also in sourсe #XX -- [ Pg.806 ]




SEARCH



Composite Compounder

© 2024 chempedia.info