Binder high corrosion resistance

Development of Epoxy Resin-Based Binders for Electrodeposition Coatings with High Corrosion Resistance... 

The deterioration mechanism for WC-Co (and similar materials) is assumed to be as follows the binder phase of metal around the carbide particles corrodes away so fliat the WC particles are more easily removed by erosion. The transition from the unexposed state to a corroded and eroded state is schematically illustrated in Figure 7.43. It should be noticed that under extremely erosive conditions or if die metal phase is highly corrosion resistant in the actual environment, erosion is dominating and the effect of die shown mechanism may be insignificant. 

Portland-slag cements may be employed in most applications in which plain Portland cement is also used, as long as a high short-term strength is not required. The main areas of their use are applications in which a high corrosion resistance or a slow hydration heat liberation of the binder are required. 

The industrial value of furfuryl alcohol is a consequence of its low viscosity, high reactivity, and the outstanding chemical, mechanical, and thermal properties of its polymers, corrosion resistance, nonburning, low smoke emission, and exceUent char formation. The reactivity profile of furfuryl alcohol and resins is such that final curing can take place at ambient temperature with strong acids or at elevated temperature with latent acids. Major markets for furfuryl alcohol resins include the production of cores and molds for casting metals, corrosion-resistant fiber-reinforced plastics (FRPs), binders for refractories and corrosion-resistant cements and mortars. 

The "high-hydroxyl principle was discovered in experiments in which the coatings were conventionally applied from organic solvent solutions. We then set out to develop ED binders conforming to this principle. Apart from offering good corrosion resistance, such binders must of course meet a number of further requirements, such as... 

In conclusion, it should be emphasized that the main advantage of polymer concretes is high chemical resistance characterized by long-term resistance to corrosive environments. Composition based on polymer binders are the most promising for use in these conditions. 

Highly diffusive penetration of SPC can be drastically lowered by active additives that are capable of raising SPC density, and, therefore, its corrosion resistance. As indicated previously, the most effective results were obtained by introduction of FA or TFS additives. Addition of monomeric additives to silicate composition improves the physical-mechanical characteristics and chemical resistance of silicate compositions due to improvement in the quality of silicate bonds and better adhesion between the binder and coarse filler [1], In other words, the influence of the monomeric additives is conditioned by consolidation of liquid glass gel during hardening and modifications of alkaline components due to inoculation of furan radicals. 

Biomass-based fiiran resins use furfuryl alcohol (FA) [17]. It has affected the success of the rather old biomass-based chemical industry. This reactive alcohol plays a vital role in the production of foundry sand binders. For over 30 years these fiiran resins have been extensively used in the foundry industry to produce cores that yield high-quality castings. Despite the good chemical, mechanical and thermal properties of FA resins/polymers such as corrosion resistance, fiame retardancy, low smoke emission and excellent char formation, the consumption of these bio-based resins in other markets is of minor significance ... 

The binder itself can also prevent corrosion if it has good barrier properties and a high electrical resistance. 

An unaccelerated, low viscosity, styrene free, corrosion resistant (to acidic and aikaline environments), flame retardant (<25 ASTM E-84 with 3% antimony trioxide) vinyl ester, offering high strength, excellent impact strength and toughness, designed to bond Hetron FR 992 resin laminates and meet the low odour requirements of the semiconductor and other industries. Since this resin does not contain styrene, the glass reinforcement must exhibit very little binder conventional CSM s do not wet-out well with this resin. 

---