Plastics : A comprehensive explanation of biodegradable plastics

Biodegradable plastics are materials designed to break down completely through natural processes when exposed to specific environmental conditions like moisture, temperature, and microorganisms. Unlike conventional plastics that can last hundreds of years, these materials decompose into natural substances like water, carbon dioxide, and biomass.

Types of Biodegradable Plastics:

Natural-Based:

• Made from renewable resources like corn starch, vegetable oils, or cellulose like the PLA (Polylactic Acid) made from corn starch
• Generally decompose more easily
• Often used in food packaging and disposable items

Corn starch in plastics: corn starch is a natural polymer extracted from corn kernels. In the plastic industry, it's used as a base material for making biodegradable plastics. When processed correctly, corn starch can be transformed into a material that behaves like conventional plastic but breaks down naturally.
Cellulose in plastics: Cellulose is the most abundant natural polymer, found in plant cell walls. In plastic production, it's extracted mainly from wood or cotton and can be modified to create biodegradable plastic alternatives. 
PLA (Polylactic Acid): is a biodegradable plastic made from fermented plant starch (usually corn). It is widely used in food packaging, disposable tableware, it's food-safe and breaks down naturally in industrial composting facilities.

Synthetic-Based:

• Chemically engineered to biodegrade like the  PBAT (Polybutylene Adipate Terephthalate)
• Can be designed for specific breakdown times
• Used in agricultural films and packaging

PBAT (Polybutylene Adipate Terephthalate) is a synthetic biodegradable plastic that's engineered to break down through natural processes. Unlike natural-based options like PLA, it's made from petroleum but chemically designed to degrade. It offers the flexibility and toughness of traditional plastic while being able to decompose into water, CO2, and biomass (organic material that comes from plants, animals, and their waste products) under proper conditions. PBAT is commonly used in agricultural films, compostable bags, and food packaging, making it a practical choice when both durability and biodegradability are needed.

Breakdown Process:

• Requires specific conditions (temperature, humidity, microorganisms)
• Can take weeks to several months depending on the material
• Some need industrial composting facilities
• Others can break down in home compost or landfill conditions

Applications:

• Food packaging and containers
• Agricultural mulch films
• Shopping bags
• Disposable cutlery
• Medical applications (dissolvable sutures)
• Compost bags

Agricultural Mulch Films: are thin plastic sheets used in farming to cover soil around crops. They help control weeds, maintain soil moisture, and regulate temperature. Biodegradable versions are designed to break down naturally in the soil after use, eliminating removal and disposal needs. 

Key Benefits:

• Reduced environmental impact
• Lower carbon footprint
• Less persistence in nature
• Made from renewable resources
• Support circular economy goals

Circular Economy in Agricultural Films: is a sustainable approach where mulch films complete a natural cycle. Films are made from bio-based or biodegradable materials, used for one growing season, then break down into natural substances in the soil. These breakdown products become nutrients for future crops, creating a closed loop where waste becomes a resource.

Challenges:

• Often more expensive than traditional plastics
• May require specific disposal conditions
• Performance limitations (heat resistance, strength)
• Need proper labeling to ensure correct disposal
• Varying decomposition times

Industry Standards:

• Must meet specific certification requirements
• Testing for actual biodegradability
• Clear labeling requirements
• Different standards for home vs. industrial composting

Environmental Impact:

• Reduces plastic pollution
• Lower greenhouse gas emissions
• Less dependence on fossil fuels
• Supports sustainable agriculture (for bio-based materials)
• Helps meet environmental regulations

Future Developments:

• Improving material properties
• Reducing production costs
• Developing new applications
• Enhanced breakdown efficiency
• Better recycling compatibility