Extracted pigment makes for stronger plastic
If you want longer-lasting plastic foams or textiles, the answer may lie in your skin, hair and eyes. All of those body parts get their color from a naturally-occurring pigment known as melanin, which is also found in other animals. Now, scientists from China's Jiangnan University have determined that even a small amount of added melanin makes polyurethane much stronger.
In lab tests, a team led by Mingqing Chen and Weifu Dong started by extracting melanin from ink sacs of cuttlefish and blending it into ordinary liquid polyurethane.
Even when the resulting cured foam contained as little as two percent melanin, it still exhibited about a 10-fold increase in both toughness (impact-resistance) and tensile strength (stretchability). Whereas unaltered polyurethane could stretch by 770 percent before breaking, the foam with added melanin was able to get to 1,880 percent.
According to the scientists, this increase was at least partly due to the melanin nanoparticles' tendency to link with the polymer chains that make up the polyurethane.
A paper on the research was recently published in the journal Biomacromolecules.
Source: American Chemical Society