Epoxy resins corrosion behavior

Corrosion Behavior of Epoxy and Unsaturated Polyester Resins in Alkaline Solution... 

The effect of temperature and concentration on corrosion behavior and corrosion mechanism of epoxy and polyester resins in NaOH solution were studied, and were discussed by considering their structures. 

Different behaviors and mechanisms were clearly recognized between these resins. Epoxy resin cured with amine showed no degradation during immersion because of its stable crosslinks. Epoxy resin cured with anhydride showed the uniform corrosion with the softening and dissolution of the surface and also behaved similar to the oxidation corrosion of the metal at high temperature obeying linear law. 

In alkaline and acid solutions, thermosets containing ester groups are degrated mainly due to the hydrolysis of the esters (1-6) But in case of the resin crosslinked by ester bonds such as some epoxy resins (7-9). corrosion behavior is though to be different from that of the resin which has ester bonds in the main chain. 

CORROSION BEHAVIOR OF EPOXY RESINS (a) Epoxy Resin Cured with MTHPA... 

The results were positive and promising. Bagherzadeh et al. [81] found that the anticorrosion performance of a two-component water-based epoxy resin coating system was improved by adding only 0.02 wt% nano-PANI. Ahmad et al. [82] investigated the corrosion protection behavior of waterborne resorcinol formaldehyde (RF)-cured composite coatings of poly(l-naphthylamine) (PNA)/poly(vinyl alcohol) (PVA) on mild steel, and even superior corrosion protective performance was observed in different corrosive media when compared with the reported solvent-based conductive polymer coatings. 

Amongst the outstanding properties of the epoxy resins, their great resistance to chemical agents and corrosion are noteworthy. Other properties include excellent electrical and mechanical behavior, flexibility and moderate toughness, great... 

Hidemitsu Hojo et al. (Hidemitsu et al., 1998) reviewed the behavior, the forms and mechanisms of corrosion of resins and glass fiber reinforced plastics under several aqueous solutions. They concluded that the concept of the corrosion rate of metals could be applied even in plastics and fiber reinforced plastics for each corrosion form. The corrosion resistance of the composites is mainly dependant on the resin s corrosion resistance properties and the corrosion crack propagation. Applications requiring corrosion resistant composite materials usually use epoxy and polyester resin as the composite matrix because these thermosets have high resistance to chemical attack. Among the various type of resins epoxies dominate the... 

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