Oxidation

The breakdown of polymer surfaces by ultraviolet radiation, causing chalking, discolouration, embrittlement and loss of gloss. Exposed resins, membranes and coatings are protected with UV stabilisers, pigmented gelcoats or sacrificial surface layers.

Chemical degradation caused by reaction with water, which breaks susceptible bonds such as the ester linkages in polyesters and some polyurethanes. Warm, humid conditions accelerate hydrolysis, which can degrade laminates, adhesives and membrane reinforcements over time.

The gradual change in the appearance and properties of a material caused by outdoor exposure to ultraviolet radiation, moisture, temperature cycling and airborne pollutants. Coating and material durability is assessed by natural exposure trials and by accelerated weathering tests in the laboratory.

Accelerated corrosion of the less noble material when two dissimilar conductors are electrically connected in an electrolyte such as seawater. Carbon fibre composites in contact with aluminium or steel can drive galvanic attack, so joints are isolated with sealants, coatings or an insulating glass ply.