Problem 22 - Chemistry in 30 days

Question

Which of the following is a biodegradable polymer ? (a) PVC (b) Nylon-6 (c) Cellulose (d) Polythene

Step-by-Step Solution

Answer

Cellulose is the biodegradable polymer.

Step 1: Understanding Biodegradable Polymers

Biodegradable polymers are materials that can be broken down by microorganisms into water, carbon dioxide (or methane), and biomass. They are environmentally friendly and contrast with non-biodegradable polymers that may persist in the environment for long periods.

Step 2: Identifying PVC

Polyvinyl Chloride (PVC) is a synthetic plastic polymer commonly used in construction, piping, and medical devices. PVC is not biodegradable as it does not break down easily in the natural environment by microbial action.

Step 3: Identifying Nylon-6

Nylon-6 is a type of synthetic polymer derived from petrochemicals. It is commonly used in textiles, carpets, and engineering plastics. Nylon-6 is not considered biodegradable as it is resistant to microbial degradation.

Step 4: Identifying Cellulose

Cellulose is a natural polymer found in the cell walls of plants. It is composed of linked glucose units and is biodegradable, as microorganisms can break it down into basic sugars through enzymatic activity.

Step 5: Identifying Polythene

Polythene, commonly known as polyethylene, is a widely used plastic in packaging and containers. It is a synthetic polymer that resists biodegradation and accumulates in the environment.

Step 6: Conclusion

Among the given options, cellulose is the only polymer that is biodegradable. It is naturally occurring and can be decomposed by microorganisms.

Key Concepts

Synthetic Polymers

Synthetic polymers are man-made materials composed of long chains of repeating units, called monomers. They are created through a process called polymerization. These materials are highly versatile and can be engineered to have specific properties for a wide range of applications. Some common synthetic polymers include:

• Polyethylene (Polythene)
• Polyvinyl Chloride (PVC)
• Nylon-6
• Polystyrene

Synthetic polymers are extensively used in various industries, such as packaging, construction, textiles, and automotive. Despite their practicality, they pose significant environmental challenges due to their resistance to natural degradation. Unlike biodegradable materials, synthetic polymers do not break down easily, leading to accumulation in landfills and oceans. This persistence in the environment contributes to pollution and poses risks to wildlife and human health.
Using biodegradable alternatives or promoting recycling and responsible disposal can help mitigate the environmental impact of synthetic polymers.

Natural Polymers

Natural polymers are substances composed of long molecular chains, much like synthetic polymers, but occur naturally in the environment. These polymers are crucial components of living organisms and have a variety of applications. Examples of natural polymers include:

• Cellulose, found in plant cell walls
• Starch, common in many plants and used as an energy source
• Proteins, which perform numerous functions in organisms
• DNA, which carries genetic information

Cellulose is a prime example of a biodegradable natural polymer. It is composed of glucose molecules that can be broken down by microorganisms. This process of microbial action transforms cellulose into simpler substances, making it environmentally friendly.
Natural polymers play critical roles in biological systems and are essential for life processes. Their ability to decompose naturally makes them sustainable materials with minimal environmental harm.

Environmental Impact of Plastics

Plastics are indispensable in modern life but have severe environmental implications due to their durability and longevity. Their widespread use results in various issues:

• Land and ocean pollution: Plastics often end up in natural habitats, harming wildlife and marine life.
• Resource depletion: The production of synthetic polymers consumes natural resources, especially petrochemicals.
• Waste management challenges: Non-biodegradable plastics contribute to landfill overflow and are difficult to manage sustainably.

One of the significant concerns with plastics is their resistance to degradation. Most synthetic polymers linger in the environment for hundreds of years. This persistence can stifle ecosystems and create microplastics that contaminate food chains.
Efforts to address these issues include promoting biodegradable plastics, improving recycling technologies, and encouraging reduced plastic consumption. Transitioning to sustainable alternatives can significantly reduce the environmental footprint of plastics, ensuring a healthier planet for future generations.