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Surface energy of plastic

One can obtain a relationship (Eq. (2.11)) between the critical surface tension and the solid-vapor surface tension by setting the contact angle to 0 in Young s equation (Eq. (2.6)). Therefore, critical surface tension is smaller than solid-vapor surface tension. Figure 2.7 shows the effect of temperature on the critical surface tension of two plastics. The surface energy of plastics decreases with temperature. [Pg.30]

The increase in surface energy of plastic occurs through the surface oxidation of the polymer chains... [Pg.57]

Figure 5.9 Surface energy of plastics versus duration of corona discharge treatment. Figure 5.9 Surface energy of plastics versus duration of corona discharge treatment.
Most organic adhesives readily wet metal adherends. On the other hand, many solid organic substrates have surface tensions lower than those of common adhesives. The criteria for good wetting requires the adhesives to have a lower surface tension than the substrate, which explains, in part, why organic adhesives such as epoxies have excellent adhesion to metals but offer weak adhesion on untreated polymeric substrates such as polyethylene, polypropylene, and fluoroplastics [16]. The surface energy of plastic substrates can be increased by various treatment techniques to allow wetting. [Pg.10]

Surface energy of plastics decreases with increasing temperature. Consequently, a molten polymer has a lower surface than its solid form. Surface energies of a number of common polymers are presented in Table 2.7. [Pg.31]

In order to determine the efficiency of the surface production process, tests were carried out with sodium chloride and it was found that 90 J was required to produce 1 m2 of new surface. As the theoretical value of the surface energy of sodium chloride is only 0.08 J/m2, the efficiency of the process is about 0.1 per cent. Zeleny and Piret(18) have reported calorimetric studies on the crushing of glass and quartz. It was found that a fairly constant energy was required of 77 J/m2 of new surface created, compared with a surface-energy value of less than 5 J/m2. In some cases over 50 per cent of the energy supplied was used to produce plastic deformation of the steel crusher surfaces. [Pg.103]

Some grades of PCC are surface coated to improve handling characteristics and dispersability in, for example, plastics. Additives include fatty acids, resins and wetting agents. They help to reduce the surface energy of the calcium carbonate and improve dispersion in organic materials. [Pg.353]

Plasma treatment of PDMS followed by adsorption of self-assembled silane monolayers has enabled us to controllably modify the surface energy of elastomer surfaces as described in the section on the Johnson, Kendall, and Roberts approach to deriving the surface free energy of solids. A similar treatment of silicon substrates has produced a useful, low—hysteresis model substrate for contact angle study. There are three types of PDMS contact angle substrates usually studied fluids baked or otherwise chemisorbed on solids such as glass or metals cross-linked coatings on flexible substrates, such as paper or plastic film PDMS elastomer surfaces. [Pg.680]


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See also in sourсe #XX -- [ Pg.97 ]




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Plasticization energy

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