Microcrystalline paraffin wax

Beeswax is the most important of the insect waxes. As mentioned above it comes from the honeycomb found in beehives and consists primarily of the palmitic ester of myricyl alcohol (see Table 1 for complete chemical analysis). Beeswax resembles the microcrystalline/paraffin waxes derived from petroleum. It is noted for its plasticity, ductility and its ability to form stable emulsions... 

Smooth surfaces were obtained on the Teflon samples by placing them between photographic ferrotype plates in a heated hydraulic press at about 300°F. and 2000 p.s.i.g. on a 4-inch ram. Blocks of microcrystalline paraffin wax (Enjay) were smoothed by passing a warm spatula over their surface. 

Ointments are generally composed of singlephase hydrophobic bases, such as pharmaceutical grades of soft paraffin or microcrystalline paraffin wax. 

Sperber et al.,16 of Hamburg University, made structural assignments to the carbons in two macro- and two microcrystalline paraffin waxes, each deoiled and... 

Waxes are derived from petroleum and are of two common types, paraffin and microcrystalline. Paraffin waxes have lower carbon numbers, a higher proportion of straight-chain hydrocarbons, and lower melting points compared to the microcrystallines. Typical carbon numbers are n = 20 - 50 for paraffin waxes and n = 30 - 70 for microcrystallines. 

There is very little published information on the thermal decomposition process for liquid gold films. Deram et al. recently published their work on the thermal decomposition and thin-film formation of a commercial thermoplastic liquid gold ink [50]. The exact composition of the formulation studied was not determined, but it was believed to consist of a gold mercaptide containing aryl or ester functional groups in combination with resins and microcrystalline paraffin wax. 

The exact formulations for inlay casting waxes are considered trade secrets, and Htfle has been pubUshed on the subject. A binary mixture of 65—75 wt % paraffin wax (60—63°C) and a microcrystalline wax having a melting point >60° C has been suggested (127). This produces a mixture having a sohd—sohd transition point at about 37°C with htfle plastic deformation (1—3%) at 37°C and a desirable plasticity at 45°C (73—77%) (128). 

Although the true waxes, such as beeswax, are esters of fatty acids with alcohols, the term is often applied to certain solid substances which melt at fairly low temperatures, e.g., paraffin wax. Paraffin waxes (crystalline and microcrystalline) are obtained from the refining of petroleum, and are used in rubber compounding as protective agents. They have the property of blooming to the surface of the product, forming a thin film which replenishes itself if removed in service. 

These waxes have branched structures of higher molecular weight (40-70 carbon atoms) than paraffin waxes and form a quite different crystalline structure on the surface of the rubber when emerging from solution from within the vulcanised rubber. Microcrystalline waxes form smaller crystals, which pack tighter together to form a more coherent, much more flexible film on the rubber surface which is more resistant to ozone penetration. 

The waxes consist of both cyclic and paraffin hydrocarbons. At similar melting points, the waxes have a much higher molecular weight than paraffin waxes and are less stable. Ceresine waxes have a very delicate crystalline structure, with fine needle or short plate crystals. Properly constituted blends of ceresine and paraffin waxes have a dense microcrystalline structure. 

Wax is of two general types (1) paraffin wax in petroleum distillates, and (2) microcrystalline wax in petroleum residua. 

Microcrystalline wax wax extracted from certain petroleum residua and having a finer and less apparent crystalline structure than paraffin wax. 

Saturated Paraffin waxes, microcrystalline wax, earth wax, polyethylene waxes. 

Knowledge of the structure, crystal form, reactions, etc., of the microcrystalline waxes must be worked out in as full detail as the paraffin waxes before we reach an understanding of the whole subject. In fact, the type of work recently reported by Mazee (69) would indicate that much can still be learned about paraffin wax, particularly through close study of pure paraffins and their mixtures. 

The largest single source of hydrocarbon waxes is from petroleum. These waxes are a byproduct of the gasoline/oil refinement process. Petroleum waxes are divided into two main groups, paraffin waxes and microcrystalline waxes, both of which are hydrocarbons... 

Many waxy materials in the various categories covered above were evaluated. It was observed that two classes of materials stood out 1) Paraffin waxes plus an active agent such as Alox, and 2) certain amorphous (microcrystalline) waxes with and without the addition of active substances. The results of tests indicated that the five best waxes of those studied in Ref 11 are those shown in Table 7... 

Ref 94 covers studies involving use of Mobil-wax 2300 microcrystalline wax, paraffin wax, ethylene vinyl acetate copolymer (Elvax 40,... 

Microcrystalline petroleum waxes are characterized not only by microcrystalline structure but by very high average molecular weight, manifested by a milch higher viscosity than that of paraffin wax. The chlorophyll present in plants is considered to be a microcrystalline wax. 

When a microcrystalline wax is added to melted paraffin it acts like a solute with paraffin as the solvent the melting point of the blend is greatly elevated, and the crystallization of the paraffin is depressed. The behavior is that of a two-phase system until about 15% of the microcrystalline wax has been added. With the addition of 15 percent of the petrolatum wax (M.P. 188°F 86.6°C) the melting point of the paraffin is elevated from 130 to 16C °F (54 to 71°C). For many industrial uses microcrystalline wax is admixed with paraffin wax. 

Paraffin wax is a solid crystalline mixture of straight-chain (normal) hydrocarbons ranging from C20 to C30 and possibly higher, that is, CH3(CH2)nCH3 where n > 18. It is distinguished by its solid state at ordinary temperatures [25°C (77°F)] and low viscosity [35 to 45 SUS at 99°C (210°F)] when melted. However, in contrast to petroleum wax, petrolatum (petroleum jelly), paraffin wax does in fact contain both solid and liquid hydrocarbons. It is essentially a low-melting, ductile, microcrystalline wax. 

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