Surface and bulk erosion

Surface and bulk erosion are two different forms of erosion that describe how a degrading polymer erodes. In surface erosion, the polymer degrades from the exterior surface. The inside of the material does not degrade until all the surrounding material around it has been degraded. In bulk erosion, degradation occurs throughout the whole material equally. Both the surface and the inside of the material degrade. Surface erosion and bulk erosion are not exclusive, many materials undergo a combination of surface and bulk erosion. Therefore, surface and bulk erosion can be thought of as a spectrum instead of two separate categories.

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