Epoxy binders

Aggregate Epoxy binder compositions Mass loss after abrasion (g)... 

Other common binders include nitrocellulose (acetone as the solvent), polyvinyl alcohol (used with water), and Laminae (an unsaturated polyester crosslinked with styrene — the material is a liquid until cured by catalyst, heat, or both, and no solvent is required). Epoxy binders can also be used in hquid form during the mixing process and then allowed to cure to leave a final, rigid product. 

HAP (or LiC104.2NH20H or MgC104.4NH2OH) and 20% epoxy binder... 

In addition to providing the properties of polyurethane chemistry, the authors reported that HNIPUs also exhibit the chemical resistance of epoxy binders. Potential uses of HNIPUs include commercial application in paints, varnishes, adhesives, caulking compounds, flooring/industrial coatings, foams, and composite materials. 

Soviet scientists have developed a cold-cure EDS material87). Note that the epoxy binders used are in fact generally hot-cure oligomers (from the point of view of the functional groups used and the completion of cure). It turned out that the forced elastic limit and the compression elastic modulus of the matrix are the same for both hot and cold cures. The good mechanical properties of a cold cured syntactic foam seem to be due to strong intermolecular bonds. 

Until recently, the materials made from epoxy binders and glass microspheres were believed to be the strongest syntactic foams. However, several papers 26,39) have shown that, when carbon microspheres replace those of glass, the material becomes stronger, more water resistant, and more capable to withstand hydrostatic pressure (for the same filler concentration) (Table 13). The smaller the carbon microspheres, the stronger are the resulting foams, 9 135). Carbon microspheres also improve the mechanical properties of phenolic and resol syntactic materials (Table 14) 38). 

The addition of a filler changes the kinetics of the water absorption by an epoxy binder, water absorption becoming a multistage process (Fig. 12). Crank and Park150) have given the equation for the kinetics of water sorption by a thin plate, as well as a solution of the Fickian diffusion differential Equation as ... 

The addition of microspheres lowers the glass transition temperature of the epoxy binder (Fig. 13). This seems to be because the filler causes defects in the matrix network. Equal diffusion coefficients of filled and unfilled epoxy binder indicates, therefore, that the diffusion processes are insensitive to binder changes. The sorption of water by epoxy resins is in fact known to depend mainly on their polarity and only slightly on the three-dimensional compactness of the network. 

Fig. 13a-c. Thermomechanical curves for a unfilled epoxy binder, b epoxy syntactic foam with dressed glass microspheres, c syntactic foam with undressed filler (1) iiiitial sample and (2) sample after 2 months in contact with water us)... 

Manson and Chin 151) reported that the addition of filler to an epoxy binder reduces the epoxy s permeability coefficient (P), as well as the solubility of water in the resin (S) and that the reduction is stronger than expected from theory 1 2). Diffusion coefficients calculated from P and S for the unfilled resin were found to be somewhat higher than those for filled resin. The difference seems to be due to the formation of ordered layers, up to 4 pm thick, around every filler particle. The layers form because of residual stresses caused by the difference between the binder and filler coefficients of thermal expansion. The effective activation energy for water to penetrate into these materials, calculated in the 0-100 °C temperature range, is 54.3 kJ/mol151). 

Fig. 22a and b. Behavior of syntactic foams during thermal treatment. Key a Thermogram of the hardening process for (1) Unfilled epoxy and (2) Epoxy syntactic foam with phenolic microspheres, b Glass transition temperature of the epoxy binder versus concentration of phenolic microspheres 1621... 

Petrographic studies were conducted using the air-dried pulverized coal mixed with a nonreactive epoxy binder. Air drying was performed at ambient temperature. The ASTM method specifies minus 20 mesh (minus 850um). The Rasa coal sample was finer. The mixture, which contained about 18 to 25 percent... 

The theoretical study of incendiary reactions has been aided by the use of com.puter programs for the study of the equil products (Refs 15 41), as well as for the prediction of the adiabatic reaction temps. An example of the complexity of the reaction products of a fluorocarbon, compounded with 5% epoxy binder, is given by Tanner (Ref 80). It will be observed, that only the carbon remains as solid product, and that the effect of the fluorine is one of increasing the fraction of gaseous products, as well as to provide the thermal energy (see Table 8)... 

The crack-repair process also utilises a thixotropic epoxy compound known as a surface sealant. This is spread over the face of the crack primarily to prevent liquid epoxy binder from oozing out when injected into the cracks. It is also used for bonding the injection nipples to the surface of the cracks. 

A novel nonisocyanate polyurethane binder for monolithic flooring and industrial paint compositions was produced on an industrial scale [34], The two component binders have unique properties that combine the best mechanical properties of polyurethane and the chemical resistance of epoxy binders [35,36], The polyurethane binders do not present health hazards because they do not consist of isocyanate... 

JL 43155AS, 43176. [Acheson Colloids] Silver pigment/epoxy binder blends EMC shielding coating for metals. 

Obscurants are another class of substances employed in warfare to generate thick black clouds to make objects opaque to visible and infrared radiation. Such substances used to block visible light include various petroleum products such as crude oil, motor oil, fog oil, exhaust of the coal, graphite, brass, dyes, titanium tetrachloride, chlorosulfonic acid, zinc chloride and phosphorous munitions containing red or white phosphorous in butyl rubber or polymer epoxy binder. Certain obscurants such as chlorosulfonic acid and titanium tetrachloride are widely corrosive... 

If the crack is deep, the epoxy binder may be introduced in stages, to permit deep penetration. Succeeding pours... 

Priming is often necessary before placement of the mortar. A small amount of the mixed epoxy binder may be used to be applied to the surface on which the epoxy mortar is to be bonded. The volume of a batch of epoxy mortar should not exceed that which can be placed within one hour. Working time of the mixture may be extended by spreading the mixture out to prevent the development of an.excessive exotherm. 

A sand filled epoxy compound will have lower stresses because the coefficient of thermal expansion will have been reduced and will have been brought closer to the coefficient of thermal expansion of Portland cement concrete. Some of the requirements for an epoxy system, based on a polysulfide-modified epoxy binder, are typically as follows ... 

As thermosetting binder, an epoxy resin is used (49). Such an epoxy compound can be conventionally cured with a carboxylic acid. The epoxy binder is produced by the radical polymerization of glycidyl methacrylate and methyl methacrylate. As initiator ferf-butylperoxy-2-ethyIhexanoate is used. 

As the measurements have shown, thermal properties of filled polymers depend considerably on filler orientation. Thermal conductivity and specific heat of glass plastics with formaldehyde and epoxy binder increase with increasing temperature, whereas thermal diffusivity falls in inverse proportion with temperature. The direction of the heat flux and orientation of the filler are responsible for the conductance and thermal diffusion in a given direction. Specific heat does not practically depend on the heat flux direction, since it characterizes the scalar value, i.e., energy accumulation. 

Fig. 1. Thermal conductivity (X, W/m K) of glass-carbon fibres EDT-10 on the basis of epoxy binder and AG-4C on the basis of phenoloformaldehyde binder.

---