Basic Binders

2 Monodentate Ligands - The Simple Type 2.2.1 Basic Binders 

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The basic binder application rate, B, is then determined by the following formula ... 

Having determined the basic binder application rate, By, for conventional bitumen, the basic binder application rate for modified bitumen, bitumen emulsion or polymer-modified bitumen emulsion can calculated using one of the following equations ... 

The basic binder application rate is rounded to the nearest 0.1, and in the bitumen emulsion or polymer-modified bitumen emulsion, it refers to residual bitumen. 

The allowances are determined to the nearest 0.1 L/m and are cumulative. They must be added to or subtracted from the basic binder application rate. Hence, the design binder application rate, B, is determined by the following equation ... 

When the average least dimension (ALD) for size 7 mm and smaller aggregates is not available, the determination of the basic binder application rate is carried out using Table 15.9. 

The lower of the basic application rate values is recommended to be selected for use with flaky aggregates or where traffic includes heavy vehicles of 15% or higher. If not certain of the conditions and traffic composition, but it appears to be normal , it is recommended that the mid-point basic binder application be selected (Austroads 2006). 

Table 15.9 Basic binder application rates for size 7 mm and smaller aggregates...

In particular, the basic binder application rate for first application for conventional bitumen, B, i> is determined first and then the design binder application rate for first application for conventional bitumen, considering allowances for surface texture, aggregate embedment and so on, as for single surface dressing. 

The basic binder application for second application, B, 2> is determined in exactly the same way as the first application, except for the determination of aggregate shape factor, Ya. In this case, the aggregate shape factor takes values from Table 15.9 considering that the lower of the basic binder application rates should be selected for use with flaky aggregates (FI > 25%) the higher of the basic binder application rates should be selected for use with more cubically shaped aggregates. 

The design binder application rate for second application, 5 2 is equal to the basic binder application for second application, B, 2, since allowances for surface texture, embedment or pavement absorption are not applied for the second application seal binder. Hence, = Bi,2 (in L/m ). 

High Carbon Yield. Furfuryl alcohol and furfural are reactive solvents (monomers) and are effective in producing high carbon yield (heat induced carbonization in a reducing atmosphere). They function as binders for refractory materials or carbon bodies. Furfuryl alcohol usually requires acidic catalysis and furfural basic catalysis. Mixtures of furfuryl alcohol and furfural are generally catalyzed with acid although some systems may be catalyzed with base. 

Furfuryl alcohol alone, or in combination with other cross-linkable binders such as phenoHc reins, chemical by-products and pitch, catalyzed with acid, gives carbon yields of 35—56%. Furfural together with cyclohexanone, pitch, or phenoHc resins gives, under acid catalysis, yields of 35—55% carbon under basic catalysis yields of 5—50% are achieved. FurfuryHdeneacetone resins (13 and 14), catalyzed by acid or base, give carbon yields of 48—56 and... 

Various other soft materials without the layer—lattice stmcture are used as soHd lubricants (58), eg, basic white lead or lead carbonate [598-63-0] used in thread compounds, lime [1305-78-8] as a carrier in wire drawing, talc [14807-96-6] and bentonite [1302-78-9] as fillers for grease for cable pulling, and zinc oxide [1314-13-2] in high load capacity greases. Graphite fluoride is effective as a thin-film lubricant up to 400°C and is especially useful with a suitable binder such as polyimide varnish (59). Boric acid has been shown to have promise as a self-replenishing soHd composite (60). 

The purity of oxygen from chlorate candles before and after gas filtration is indicated in Table 2. A particulate filter is always used. Filter chemicals are HopcaUte, which oxidizes CO to CO2 molecular sieves (qv), which remove chlorine compounds and basic materials, eg, soda lime, which removes CO2 and chlorine compounds. Other than H2O and N2, impurity levels of <1 ppm can be attained. Moisture can be reduced by using a desiccant (see Desiccants). Gas purity is a function of candle packaging as well as composition. A hotter burning unit, eg, one in which steel wool is the binder, generates more impurities. 

Incorporation of less than a stoichiometric amount of alkyl sulfonamides of copper phthalocyanines into copper phthalocyanine improves the pigment s properties in rotogravure inks (67). Monomeric and polymeric phthalocyanine derivatives with basic substituents adsorb strongly to the pigment surface and promote the adsorption of binder molecules (68—72). 

For binder preparation, dilute hydrochloric or acetic acids are preferred, because these faciUtate formation of stable silanol condensation products. When more complete condensation or gelation is preferred, a wider range of catalysts, including moderately basic ones, is employed. These materials, which are often called hardeners or accelerators, include aqueous ammonia, ammonium carbonate, triethanolamine, calcium hydroxide, magnesium oxide, dicyclohexylamine, alcohoHc ammonium acetate, and tributyltin oxide (11,12). 

Synthetic resins, such as phenoHc and cresyUc resins (see Phenolic resins), are the most commonly used friction material binders, and are usually modified with drying oils, elastomer, cardanol [37330-39-5] an epoxy, phosphoms- or boron-based compounds, or even combinations of two. They ate prepared by the addition of the appropriate phenol and formaldehyde [50-00-0] in the presence of an acidic or basic catalyst. Polymerization takes place at elevated temperatures. Other resin systems are based on elastomers (see Elastomers, synthetic), drying oils, or combinations of the above or other polymers. 

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