Period 3
Kevlar!!!
1. Give an analogy explaining how the chemical structure of Kevlar makes it strong.
Because the polymer Kevlar forms chains like structures, its crystallinity, the way the polymer is arranged and stacked is like stacking wood in nice tightly packed bundles. To explain the incredibly strong intermolecular forces of the hydrogen bonds I would compare it to a magnet, the chains are attracted to each other like the attraction between magnets and their hard to pull apart.
2. Provide three chemical reasons why Kevlar is much stronger than other polymers * On reason Kevlar is stronger than other polymers is because of their strong intermolecular hydrogen bonds. Unlike the van der Waals interactions that are found in other polymers, because of hydrogen bonding there are very strong intermolecular forces connecting the chains and takes a lot of energy to pull them apart. Also because the polymer Kevlar is made up of elements like carbon, oxygen, hydrogen, and oxygen its very light and has a low flammability.
* Another reason Kevlar is stronger than other polymers is because of its crystallinity. The polymer Kevlar is arranged in neat stacks, this crstallinity makes the polymer very strong, especially when there’s lots of chains staked together.
* Kevlar is also stronger than other polymers how the polymer is extend and how it’s perfectly aligned. Because it’s made out of rigid molecules it makes it easier to fully extend and create chain-like configurations. Also Kevlar hardly ever forms cis, bends in the polymers chain, because of the hydrogen molecules take up too much space and repel this bend.
3. Discuss two limitations of Kevlar, despite its apparent strength.
Kevlar's main weaknesses are that it decomposes under alkaline conditions or when exposed to chlorine, it is not strong under pressure (compressive stress) and its sensitive to ultraviolet light. Even with these weakness, people don’t abandon