Lubricants for polymers

MP-33-F. efti Ltd.] Srutitan palmi-tate softener and lubricant for polymers, emulsions, cosmetics, ointments. 

ZO-9. [Disco] Fatly acid salts and petroleum derivs. plasticizer and lubricant for polymers. 

Metasap . [Syn. Prods.] Aluminum stearate laocess aids, lubricants for polymers, specialty greases, watmr-I o( g % iis, thixotropes for paints and inks, flatting agents for lacqu flow aids for cmnents, slab dips and dusting ccmipds. fix rubber. 

The substance must be a lubricant for polymer—polymer contacts. 

Wear can he defined as the unwanted loss of material from solid surfaces owing to mechanical interaction (71). When dealing with metal surfaces, one often uses external lubricants. For polymers and polymer-based materials this is not advisable. The polymer might absorb the lubricant and swell the results would be worse than without the lubricant. 

High molecular weight paraffin waxes have very low compatibility with polar polymers and act as external lubricants for polymers such as PVC. 

Long-chain dialkyl esters have medium affinity to most polymers and can act both as external and internal lubricants for polymers they are often used to obtain a balanced lubrication [9]. 

The mechanism of boundary lubrication for polymers is generally similar to that of metals. Lubricants are known to be ineffective for polymeric surfaces, partly because of plasticization, and plasticization could weaken the interfacial forces and reduce both the shear strength and the yield pressure of the polymer. This weakening effect can be illustrated with the following equations ... 

Uses Pigment dispersant for polyolefins slip agenL antiblocking agent, and lubricant for polymer resins antistat and gloss aid for surfs, of molded and extroded prods. vise, reducer pigment dispersant in carbon black Features High m.p. 

Silicone also has wide use as an internal lubricant for polymers. While both silicone and PTFE reduce the coefficient of friction and thus the applied combined stresses, silicone functions in a completely different mode than PTFE. Silicone is used in an oil form compared to the dry state of PTFE. The concentration of PTFE throughout the polymer stays constant with time. One of the modes that PTFE functions is that of filling the opposing surface voids and providing a low friction transfer fihn. Silicone... 

Consider that at low temperatures, a lubricant is a poor solvent for polymer chains. When the temperature increases, interactions between polymer chains decrease the space occupied by the polymer ball takes on greater volume and consequently, the viscosity decrease due to the lubricant temperature increase is compensated by the unfolding of the polymer chain and the result is a reduction of the difference between the viscosities at low and high temperature, and therefore an Increase in viscosity index. 

Film stability is a primary concern for applications. LB films of photopoly-merizable polymeric amphiphiles can be made to crosslink under UV radiation to greatly enhance their thermal stability while retaining the ordered layered structure [178]. Low-molecular-weight perfluoropolyethers are important industrial lubricants for computer disk heads. These small polymers attached to a polar head form continuous films of uniform thickness on LB deposi-... 

The choice of lubricant for a particular composition and process can be quite critical but beyond stating that such materials will normally be fluid at processing temperature and should have a solubility parameter at least 3 MPa different from the polymer, little further fundamental guidance can be given and selection is normally made by an empirical trial and error basis. 

It is found that the viscosity of a paste made from a fixed polymer/plasticiser ratio depends to a great extent on the particle size and size distribution. In essence, in order to obtain a low-viscosity paste, the less the amount of plasticiser required to fill the voids between particles the better. Any additional plasticiser present is then available to act as a lubricant for the particles, facilitating their general mobility in suspension. Thus in general a paste polymer in which the pastes have a wide particle size distribution (but within the limit set by problems of plasticiser absorption and settling out, so that particles pack efficiently, will... 

As a preeminent biomaterial, silicones have been the most thoroughly studied polymer over the last half century. From lubrication for syringes to replacements for soft tissue, silicones have set the standard for excellent blood compatibility, low toxicity durability, and bioinertness. Many medical applications would not have been possible without this unique polymer. 

FAB-MS has been used for the analysis of lubricant additives, thermally labile or involatile organic compounds, such as macromolecules and dyes, and inorganic compounds. Cationic dyes and dye intermediates, which are typically acid salts, readily yield preformed ions in the FAB matrix solution. They are also very difficult to address by other MS ionisation methods due to their involatility. Lay and Chang [85] used positive ion FAB to characterise a mixture of amine and ketimine cross-linking agents for polymer coatings. Bentz et al. 

Development of new and/or improved routes for chemical building blocks for polymers, lubricants and fine chemicals, including through the integration of the biorefinery concept and products into the existing chemical production chain. 

Primary organics are emitted to the atmosphere by industrial sources (oil refineries, chemical plants, producers and users of solvents and plasticizers), vehicles (as a result of incomplete fuel combustion, oxygenated degradation products of lubricating oil, polymers from tires), and agricultural activities (use of pesticides). An exhaustive literature survey is beyond the scope of this section, but can be found in Air Quaiity Criteria for Particulate Matter many useful references are also available. 

Uses. In ultraviolet stabilizers and smoke depressants for polymers to increase the burn rate of rocket propellants to prevent erosion of space capsule shields to improve the viscosity of lubricants to catalyze polymerization reactions to catalyze combustion some derivatives used as hematinic agents... 

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