Weathering of polymers

Weathering of Chondritic Meteorites

Meteorites are frequently not the pristine record of early solar system processes that we would like them to be. Many unique meteorites, samples that can further our understanding of the environment of the early solar system, are finds, so a knowledge of terrestrial weathering becomes a requirement to accurately interpret their preterrestrial history. This chapter outlines the weathering proces...

Sunlight , UV , & Accelerated Weathering

Sunlight is an important cause of damage to plastics, textiles, paints, and other organic materials. Short wavelength ultraviolet light has long been recognized as being responsible for most of this damage2. Spectroradiometric measurements were made to quantify the wide variations in UV content of sunlight under the following conditions: direct summer sunlight, winter sunlight, sunlight filtere...

Commentary: Weathering Chicago.

Weathering of Stone Mountain Granite

The weathering of Stone Mountain Granite (adamellitc) forms kaolinite, endcllite, allophane and gibbsite of which kaolinite is the most stable. Bulk density ranges from 2.65 in fresh rock to a minimum of 1.48 in saprolite. It is a good index of weathering. Abrasion pH ranges from 5.0 in saprolite to 9.3 in fresh rock, and is direct]y related to bulk density and the amount of clay mineral. Among...

Collisional De–weathering of Asteroids?

In a recent paper (Lazzarin et al., 2006) it has been shown that the concept of space weathering, i.e. the evolution of spectroscopic surface properties with time, due to the exposure to external effects, can be extended from the S–complex asteroids to almost all asteroids. In general, the spectral slope changes with the exposure and, as a general rule, the weathering causes reddening, even if ...