Polymers

To determine which polymer is biodegradable among the given options, let's examine the characteristics of each:

1. Nylon-6, 6: Nylon-6, 6 is a type of synthetic polymer known as polyamide. It is created from hexamethylene diamine and adipic acid. This polymer is not biodegradable. It is commonly used in the textile industry for producing fabrics, ropes, and other materials.
2. Nylon 2-nylon 6: This is a copolymer made using glycolic acid (nylon-2 component) and aminocaproic acid (nylon-6 component). It is a biodegradable polymer because it can be broken down by microorganisms into smaller, environmentally-friendly molecules. This property makes it suitable for applications where environmental safety and biodegradability are concerns.
3. Nylon-6: Nylon-6, like nylon-6, 6, is another polyamide polymer. It is made from the polymerization of caprolactam. This synthetic polymer is tough and durable but not biodegradable. It is also widely used in textiles and plastic industries.
4. Buna-S (Styrene-butadiene rubber): Buna-S is a synthetic rubber copolymer made from styrene and butadiene. It is not biodegradable and is used widely in the production of car tires and various other rubber-based materials.

Considering the above explanations, nylon 2-nylon 6 is the correct answer as it is biodegradable. Its formulation allows it to break down naturally, contrasting with other synthetic polymers listed which are more resistant to environmental degradation.