Why does raw rubber turn yellow after aging?
Thread Content
After the aging of raw rubber begins, the color of the rubber mass gradually turns yellow. Why does it turn yellow and not some other color? Plastic aging also results in yellowing. A literature source was found that qualitatively identified the degradation products resulting from the aging of butyl O-rings; most of these degradation products are small-molecule substances that are gaseous at room temperature. Based on this speculation, the yellowing of the raw rubber blocks is due to the formation of gaseous substances within these blocks, which create extremely small bubbles. These bubbles cause scattering that separates white light; however, according to wavelength considerations, red light should be the most easily scattered, so the color should be red, right?
It’s likely oxidized; many organic solid oxides are yellow in color, and adding antioxidants might help improve the situation
My question is why it’s yellow and not some other color?