PLA Decomposition Experiment

The goal of our experiment is to understand how PLA (Polylactic Acid) plastics decompose in natural conditions. PLA is often marketed as a biodegradable plastic, but we wanted to test whether it breaks down easily and how long the process takes.

Brainstorm

Materials

What do we need for this project?

insulated box
transparent container
heat lamp
temperature sensor
humidity sensor
soil
PLA plastics or biodegradable plastics

Gathering PLA Materials

We collected different types of PLA plastics, such as bottles, films, and containers, which are commonly used in packaging. These materials were chosen because they are biodegradable and used in everyday products.

Setting Up the Environment

To mimic natural decomposition, we used an insulated box to control the temperature and humidity. A heat lamp was set to maintain temperatures between 55°C to 70°C, and humidity levels were carefully monitored with sensors to ensure the environment was ideal for PLA decomposition.

Decomposing the PLA

We cut the PLA plastics into smaller pieces and placed them in soil, adding moisture to keep them hydrated. The soil helped simulate the conditions where PLA might break down in nature.

Monitoring Progress

Over several weeks, we checked the temperature, humidity, and the condition of the PLA materials. We observed any changes in size, texture, or structure, and recorded these daily to track the decomposition process.

Analyzing Results

After the decomposition period, we examined the PLA samples to see how much they had broken down.

Report

Simple Steps

Step 1

Gather PLA plastics or other biodegradable plastics and cut them into smaller pieces

Step 2

Add decent amount of water into the soil to make it moisture

Step 3

Put the pieces into the soil and make sure the soil covers the pieces

Step 4

Turn on the heat lamp and make sure the temperature is between 55℃ to 70℃

Step 6

After it is completely decomposed, you can return the soil back to the environment

Step 5

Check the temperature and humidity, also observe the changes everyday

Video

Connection to SDGs

We wanted to prevent plastics from becoming toxic components that could enter bodies of water, where they pose a significant threat to aquatic life and ecosystems. By preventing this, we can ensure that the water remains clean, safe, and free from contamination, promoting a healthier environment for human and aquatic life.

Clean Water and Sanitation

Life Below Water

Plastic pollution has significant impacts on lives underwater. Those aquatic life may accidentally ingest plastics or even microplastics, causing problems for survival or death. By letting more people be aware of plastics related issues, we can reduce the plastic pollution and have a better marine environment for lives underwater.

Connection to Science

Chemistry

The issue of PLA (Polylactic Acid) recycling is closely tied to Geography, as it concerns the management of plastic waste across Taiwan’s various regions. Despite being biodegradable, PLA plastics require to decompose under specific conditions. Additionally, they are prohibited from being in Taiwan's composting sites.

Geography

The chemistry of PLA plastics involves their decomposition process, which requires specific environmental conditions. Under the right circumstances: heat, moisture, and microorganisms, PLA plastics can degrade into harmless substances, such as lactic acid.