Surface treatment of composites

Laser Surface Treatment of Composite Materials to Enhance Adhesion Properties... 

The phases and their proportions present ia hardened amalgam are controlled by many factors. The composition of the alloy the size, shape, and size distribution of the particles the thermal history of the cast ingot and the comminuted alloy and the surface treatment of the particles are some of the factors for which the manufacturer is responsible. The tooth cavity preparation and the mixing, compacting, and finishing techniques of the dentist can make the difference between satisfactory and unsatisfactory restorations, even with the best of alloys. A minimal amount of residual mercury and porosity are needed to obtain the most serviceable restorations (138). 

Surface treatment of the composite can have a significant effect on adhesion. Surface treatment enhances one or more of the mechanisms described previously. Wu et al. [15] studied the effects of surface treatment on adhesive bonding for AS-4/APC-2 laminates. They found that the greatest bond strength was achieved from acid etching and plasma etching the composite surface. Table 1 summarizes the various surface treatments that were evaluated. 

Various finishes can be achieved — gloss, satin (or egg-shell) or matt. This is accomplished by the addition of particles of size 1-5 pm of, for example, silica, china clay or the white pigment, TiCK The degree of mattness depends on various factors, such as particle size, surface treatment of the particles, rate of film formation, and the polymer composition, e.g., urethane/acrylate compared with epoxy/acrylate. The former requires smaller particles larger particles cannot be used as they create a rough surface. 

This technique involves the dispersion of a nanomaterial in a monomer (Fig. 4.8). This step requires a certain amount of time that depends on the polarity of the monomer molecules, the surface treatment of the nanomaterial, and the swelling temperature. For thermoplastics, the polymerization can be initiated either by the addition of an agent or by an increase in temperature. For thermosets such as epoxies or unsaturated polyesters, a curing agent or peroxide can be added in order to initiate the polymerization. Functionalized nanomaterials can improve their initial dispersion in the monomer and consequently in the composites. In the case of layered materials, such as clays or graphene, the most important step is the penetration of the monomer between the sheets, thus allowing the polymer chains to exfoliate the material. The... 

SURFACE TREATMENTS OF FIBERS AND EFFECTS ON COMPOSITE PROPERTIES... 

Chiipler 5. Surface treatments of fibers and effects on composite... 

Effect of size and surface treatment of carbon fibers on mechanical properties of magnesium matrix composites ... 

Delmonte, J. (1981). Surface treatments of carbon/graphite fibers and their effect on composites. In Technology of Carbon and Graphite Fiber Composites. Van Nostrand Reinhold, New York, pp. 171-197. 

Ehrburger, P., Donnet, J.B. (1985). Surface treatment of carbon fiber for resin matrices. In Strong Fibers, Handbook of Composites, Vol. 1 (W. Watt, and B.V. Perov, eds.). Elsevier Sci., Amsterdam, pp. 577-603. 

Plasma surface treatment of many polymers, including fabrics, plastics, and composites, often occurs. The production of ultra-thin films via plasma deposition is important in microelectronics, biomaterials, corrosion protection, permeation control, and for adhesion control. Plasma coatings are often on the order of 1 100 nm thick. 

Figure 5.107 Variation in toughness and shear strength for various surface treatments of continuous carbon fiber-reinforced composites. Reprinted, by permission, from T. L. Vigo and B. J. Kinzig, ed.. Composite Applications, p. 224. Copyright 1992 by VCH Publishing, Inc.

As was mentioned in the previous section two types of interactions must be considered in particulate filled polymers particle/particle and matrix/filler interaction. The first is often neglected even by compounders, in spite of the fact that its presence may cause composite properties to deteriorate significantly especially under the effect of dynamic loading conditions [18]. Many attempts have been made to change both interactions by the surface treatment of the filler, but the desired effect is often not achieved due to improper use of incorrect ideas. 

Liu, Y. and Gao, L., A study of the electrical properties of carbon nanotube-NiFe204 composites effect of the surface treatment of the carbon nanotubes , Carbon, 2005, 43, 47-52. 

Ballmann, A., et al., Surface Treatment of Polyetheretherketone Composite by Plasma... 

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