Background

One of the first synthetic plastics to be created was rooted in sustainability. In the 1860s too much ivory was being used to make billiard balls, so a type of plastic called celluloid was developed to make them with instead. Over the next century dozens of synthetic plastics were created, in many different strengths and shapes. It was thought that using these synthetic materials instead of natural resources would be beneficial to the environment.

So why then is plastic pollution one of the largest environmental catastrophes that we face today? What is it about plastic structure that allowed microplastics to become so pervasive in our environment? Whilst plastics have their place in society, we have become too reliant on single use plastics that end up in landfill or the oceans. Recycling alone will not solve this problem – but green chemistry will.

Green chemistry aims to manufacture safer materials, reduce the production of waste, improve energy conservation, and move us towards a circular economy. One of the biggest questions in green chemistry today is how to produce easy to recycle plastics using renewable resources.

Note: This program formerly ran as a Year 10 program. If your students completed the year 10 version in 2024, please do not book this for 2025 as the activities will overlap.

Prior Knowledge

Some basic idea of atoms and the particulate nature of matter.

Key Learning Question

What are the properties of plastic and how can green chemistry principles be used to find sustainable solutions?

Learning Intentions

In this program students will:

• Link the structure of plastics to their properties and functions
• Discover the origins of microplastics and their effect on the environment
• Learn some techniques for identifying different types of plastic
• Distinguish between plastic made from fossil fuels and plastic made from renewable feedstocks
• Understand the benefits to the environment of using compostable plastics
• Discover the principles of green chemistry and how these principles will help us move to a circular economy

Activities

Students will:

• Conduct simple experiments to test the properties of different types of plastic
• Examine microplastics from a range of samples
• Use cutting edge laboratory equipment to identify plastics
• Conduct experiments to compare the degradation of bioplastics compared to common synthetic plastics

VCE Chemistry Links

Unit 1 Area of Study 2: How are materials quantified and classified?

Polymers and society

• The differences between addition and condensation reactions as processes for producing natural and manufactured polymers from monomers
• The formation of addition polymers by the polymerisation of alkene monomers
• The distinction between linear (thermoplastic) and cross-linked (thermosetting) addition polymers with reference to structures and properties
• The features of linear addition polymers designed for a particular purpose, including the selection of a suitable monomer (structure and properties), chain length and degree of branching.
• The categorisation of different plastics as fossil fuel-based (HDPE, PVC, LDPE, PP, PS) and as bioplastics (PLA, Bio-PE, Bio-PP); plastic recycling (mechanical, chemical, organic), compostbility, circularity and renewability of raw ingredients
• Innovations in polymer manufacture using condensation reactions, and the breakdown of polymers using hydrolysis, contributing to the transition from a linear economy towards a circular economy

Sustainability

Sustainable development

• Goal 10: Sustainable cities and communities
• Goal 12: Responsible consumption and production

Green chemistry principles

• Design for degradation: chemical products should be designed so that at the end of their use they break down into harmless degradation products and do not persist in the environment
• Use of renewable feedstocks: Raw materials or feedstocks should be made from renewable (mainly plant based) materials, rather than from fossil fuels, whenever possible

Linear and circular economies

• Linear economy: operates on a “take-make-dispose” model, making use of resources to produce products that will be discarded after use
• Circular economy: A continuous cycle that focuses on the optimal use and re-use of resources from the extraction of raw materials through to production of new materials, followed by consumption and re-purposing of unused and waste materials