Final answer:
Polypropylene is formed by polymerizing propene monomers into a long chain with the repeating unit -CH2-CH(CH3)-. It is used in a wide range of products due to its durability and fatigue resistance.
Step-by-step explanation:
The structure of polypropylene, which is formed by the polymerization of propene (CH2=CHCH3), consists of multiple propylene monomers linked together in a chain. During this chain-growth polymerization, the double bond in each propylene monomer opens up and connects with other monomers to form a long polymer chain.
The polymer's repeating unit has the structure -CH2-CH(CH3)-, with the methyl group (-CH3) attached to every other carbon atom in the chain. This structure makes polypropylene exceptionally versatile, and is used in a variety of applications ranging from ropes and plastic bottles to non-woven fabrics and food containers.
Polypropylene is known for being robust and resistant to fatigue, which is why it's commonly used for containers and their lids. It is one of the many polymers that are derived from petrochemicals such as propylene, and like other plastics, it poses environmental concerns due to its lack of biodegradability. However, recycling initiatives help mitigate some of these impacts by reducing the demand for new petrochemical resources and minimizing environmental pollution.