Lubricant plasticizing effect

The so called plasticization effect, i.e., the depression of the glass transition temperature is also an important feature the sorbed gas acts as a kind of lubricant , making it easier for chain molecules to slip over one another, and thus causing polymer softening. 

Plastic deformation (strain). When two surfaces of ductile materials are placed in contact and the load exceeds the elastic limit of one of the two materials, plastic deformation or strain occurs. The plastic deformation of one surface when two surfaces are in solid-state contact can occur in the presence or absence of lubricants. In fact, in some instances, the presence of lubricants can increase the deformability of the solid surfaces by a mechanism such as the Rehbinder effect. Plastic deformation of the solid surface is, therefore, observed in the presence of lubricants. Plastic deformation is accommodated by the generation of slip lines for dislocation flow in the solid surface. Dislocations are line defects in the solid and they are site of higher energy state on the surface. Thus, they interact or react more rapidly with certain chemical agents than do the bulk surfaces (Buckley, 1981 Lunarska and Samatowicz, 2000). 

The characteristics of lubricants, their effects during plastics processing and their influence in the calendering process are discussed in depth. Attention is paid to the different intemal/external behaviour of lubricants, viscosity reduction by internal lubricants, fusion delay by external lubricants, shear liquefaction by lubricants and the suitability of various lubricants for the manufacture of calendered PVC films in relation to melt elasticity, release effect, flow and plate-out. 

Typically, rigid PVC formulations use about twice as much lubricant as semirigid and flexible formulations. This is because plasticizers act similar to internal lubricants as they interact with PVC, making it more mobile, and flexible. Lubricant was found to affect impact properties because these are controlled by fusion which is affected by lubricant type and concentration. Lubricant also had a plasticizing effect on polymer, which had tensile strength higher without lubricant. ... 

Uses Release and dry lubricant coating effective with all types of rubber and plastic compds. 

Korshak, V.V. et ol. (1986), Effect of friction temperature on the surface structure and wear resistance of antifriction self-lubricating plastics based on poly(phenylquinoxaline), Trenie I Iznos,... 

PVC is undoubtedly a plastic as its Tg is above ambient temperature. However, PVC is often used with additives such as plasticisers. Plasticisers cannot change intra-polymer interactions but can affect inter-polymer forces. Plasticisers, which have much smaller molecules than PVC, act as lubricants and effectively reduce inter-polymer forces, leading to a reduction of Tg. When PVC compounds have a Tg below ambient temperature, they behave like a rubber. 

The first major paper on mold release was published in 1946 by Ziegler. It contained a thorough analysis of the influence of mold material on release properties. Even more important, the paper contained a proposal for a new method of mold release testing, which gave the fundamental tool for rational analysis of the problem. More than twenty of the so-called mold lubricants were tested by the newly developed pull-out force method. In addition, the effect of lubricant on product clarity was observed - both results being considered in the final selection. In the best cases, the decrease of up to 80% of pull-out force was obtained with these tested lubricants . Plasticizers and pigments were also found to facilitate mold release properties in combination with mold release agents. 

Before leaving the topic of normal hardness it is appropriate to mention further the role of lubrication. The effect of lubrication is to produce a reduction in the apparent hardness see Figure 7. Lubrication influences the stress fields and facilitates both elastic relaxation and plastic flow. First order theoretical treatments are available. ... 

Uses Penetrant, emollient, moisturizer, lubricant, solvent in hydroalcoholic cosmetics incl. bath oils, lipsticks, men s grooming aids, hand lotions lubricant, plasticizer, solubilizer for metalworking, petrol, and plastic industries Features Nonoily mild drying effects... 

In this study, two phosphonium cation based ILs with different anions were evaluated as potential plasticizers and/or lubricants for PLA. Both ILs lowered the glass transition temperature of PLA and modified its rheological characteristics as evidenced from reduced viscosities and apparent phase separation and lubrication. The effects were much more pronounced for the IL-1 containing a hydrophobic decanoate anion, presumably as... 

Chlorinated paraffins are versatile materials and are used in widely differing appHcations. As cost-effective plasticizers, they are employed in plastics particularly PVC, mbbers, surface coatings, adhesives, and sealants. Where required they impart the additional features of fire retardance, and chemical and water resistance. In conjunction with antimony trioxide, they constitute one of the most cost-effective fire-retardant systems for polymeric materials, textiles, surface coatings, and paper products. Chlorinated paraffins are also employed as components in fat Hquors used in the leather industry, as extreme pressure additives in metal-working lubricants, and as solvents in carbonless copying paper. 

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