Fillers compounding/mixing

Keywords fillers, compounded mix, physical and mechanical properties. 

Cure systems, however, paint only part of the picmre with regard to the manufacture of mbber articles polymers and fillers are equally important in meeting performance requirements. In addition, compound mixing and processing play an important role in achieving final vulcanizate properties. 

The same approach can be applied to plastics, filled with ATH (or any other filler). A compounded mix of 60% ATH and 40% HDPE was prepared and a sample of the filled plastic was ashed. Theoretically, the amount of ash should be 39.23% by weight. This figure can be obtained by taking 65.38% ash content in ATH and taking 60% of it (because the ATH was diluted by 40% of HDPE). If to introduce the correction that there were only 2.86 water molecules per ATH (see above), the amount of ash should be 40.0%. 

Micro-Mix, Filler compounds and filler/rein-forcement blends, American Best Building Products... 

In the table 1 physical and mechanical characteristics of the inflated with organic and inorganic fillers acryUc compounded mix based on A4 acrylic dispersion are presented. The same behavior of samples based on the other acrylic dispersions was revealed. 

As it s shown in the table 1, the increase of organic filler content in compounded mix leads to deterioration of flexibility. The introduce of organic filler brings the strength increase. While the increase of content of inorganic filler (till 20%) brings noticeable deformation, though the durability decreases. 

As it s shown on the fig. 1-3, compounded mix inflated with organic filler has more homogeneous strueture then mix with inorganic filler whieh has substantively dissimilar structure. This dissimilar strueture includes ciystallites of salts, and with increasing of filler... 

Thus, fillers insert their own amendments in mechanical properties of the compounded mixes independently from each other, i.e. the presence of organic filler brings an increase of durability at small exposition in water, while inorganic filler improves flexibility of the compoimded mix. 

The filler localization experimentally determined by the use of our wetting concept is correlated to the wetting behaviour of rubber as follows the more the filler surface is wetted by a rubber phase, the more the filler is included and distributed in this phase. When filler is mixed with a single rubber, for instance SBR, a part of the rubber chains will be bonded to the active centres, which are available on the filler surface. If the rubber is extracted from the filled uncured rubber compound with a suitable solvent, the rubber molecules bound on the filler surface remain in the rubber-filler gel. In our concept, we are interested in the fraction of rubber in this rubber-filler gel. The wetting... 

In this chapter we consider types of ternary compounds other than those discussed in Chapter 6. The compoimds we discuss here contain polymers, particle fillers, and additives including processing aids and curatives. Additives mixed into polymer-filler compounds have a strong influence on the interaction of particles with each other and with the polymer matrix. The treatment of reinforcing fillers with additives is very important in the processing industry. Sections 7.2 and 7.3 may be considered a continuation to Chapter 2. Curatives, notably sulfur and its compounds, are usually used with organic accelerators to control the rate of curing step. Section 7.5 continues section 4.10. 

Three different techiuques for mixing a sihca and caibon black filled tyre tread compound were evaluated and the effect of surfactant-based process additives (modified zinc soaps and a zinc soap/resin combination designated Struktol HT 266) on productivity and compound quality investigated. Mixing methods studied involved the use of a separate filler addition stage for each component type and different orders of filler addition. Mixing efficiency and dispersion/filler interactions were examined and the effects of process additives on Mooney viseosity and extrusion assessed. The cure characteristics, physical properties and dynamic properties of the vulcanisates were also examined. 9 refs. 

Clarke,. 1. and Freakley, P.K., 1995. Modes of dispersive mixing and filler agglomerate size distributions in rubber compounds, Plast. Rubber Compos. Process. Appl. 24, 261-266. 

Filled Resins. EiEers such as glass fibers, graphite, asbestos, or powered metals are compounded into all three types of PTEE. Compounding is achieved by intimate mixing. Coagulation of the polymer with a filler produces a filled fine powder. 

Fillers. Micronized carbonate whiting is the preferred mineral fill for putty and caulking compounds based on linseed oil or plastic, and vinyl-based floor coverings. It comprises 20—60% of the raw material mix (see Fillers). 

Dicyclopentadiene is also polymerized with tungsten-based catalysts. Because the polymerization reaction produces heavily cross-Unked resins, the polymers are manufactured in a reaction injection mol ding (RIM) process, in which all catalyst components and resin modifiers are slurried in two batches of the monomer. The first batch contains the catalyst (a mixture of WCl and WOCl, nonylphenol, acetylacetone, additives, and fillers the second batch contains the co-catalyst (a combination of an alkyl aluminum compound and a Lewis base such as ether), antioxidants, and elastomeric fillers (qv) for better moldabihty (50). Mixing two Uquids in a mold results in a rapid polymerization reaction. Its rate is controlled by the ratio between the co-catalyst and the Lewis base. Depending on the catalyst composition, solidification time of the reaction mixture can vary from two seconds to an hour. Similar catalyst systems are used for polymerization of norbomene and for norbomene copolymerization with ethyhdenenorbomene. 

Plasticizers and Processing Aids. Petroleum-based oils are commonly used as plasticizers. Compound viscosity is reduced, and mixing, processing, and low temperature properties are improved. Air permeabihty is increased by adding extender oils. Plasticizers are selected for their compatibihty and low temperature properties. Butyl mbber has a solubihty parameter of ca 15.3 (f /cm ) [7.5 (cal/cm ) ], similar to paraffinic and naphthenic oils. Polybutenes, paraffin waxes, and low mol wt polyethylene can also be used as plasticizers (qv). Alkyl adipates and sebacates reduce the glass-transition temperature and improve low temperature properties. Process aids, eg, mineral mbber and Stmktol 40 ms, improve filler dispersion and cured adhesion to high unsaturated mbber substrates. 

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