4.2d_plastics

• Techniek
• HBO
• Studiejaar 4

4.2D PLASTICS

Introduction 

Most plastics are produced from petrochemicals. Motivated by the finiteness of oil reserves and threat of global warming, bio-plastics are being developed. These plastics degrade upon exposure to sunlight, water or dampness, bacteria, enzymes, wind erosion and in some cases pest or insect attack, but in most cases this does not lead to full breakdown of the plastic. When selecting materials, designers must consider the moral, ethical and environmental implications of their decisions.

Designers should prioritize ethical and environmental implications over material performance.

Yes, ethical and environmental impact is crucial.

No, material performance should be the priority.

Yes, considering moral implications is important.

No, performance should be the primary concern.

Bio-plastics should replace traditional plastics for environmental reasons.

Yes, bio-plastics are more sustainable.

No, bio-plastics are not fully biodegradable.

Yes, reducing dependence on oil is crucial.

No, bio-plastics require large-scale agricultural land.

Development of Plastics

Plastics have evolved from early rubber-based materials to modern petrochemical derivatives.

What do you already know about the development and environmental impact of plastics?

Invention and Growth of Plastics

The invention of materials like Bakelite and polyethylene, spurred by wartime needs, led to the proliferation of plastics.

Environmental Considerations

Today, environmental concerns drive the development of bio-plastics, which only partially degrade.

Partial degradation of bio-plastics still poses a threat to the environment.

Partial degradation decreases plastic pollution.

Partial degradation contributes to microplastic pollution.

Partial degradation can be managed effectively.

Partial degradation is an acceptable compromise.

The development of bio-plastics is a positive step for environmental conservation.

Bio-plastics reduce reliance on traditional plastics.

Bio-plastics have limited environmental benefits.

Bio-plastics may have unknown long-term effects.

Bio-plastics are not a sustainable solution.

Facts about Plastics 

• Technically plastics are referred to as Polymers
• Petro-chemicals are the main ingredient for modern day plastics.
• Roughly 8% of oil production is due in plastics
• The raw material for plastics (mainly oil) is extracted in a country, exported to other countries where conversion to plastics takes place and these are re-exported at considerable added value. (Int Mind)
• Bio-plastics – such as polylactic acid (PLA) resin which is made from corn or potato starch – is also biodegradable.
• Interesting note on compostability of PLA

Which raw material is mainly used in the production of plastics?

1. Oil
2. Water
3. Coal
4. Wood

What are the main ingredients for modern day plastics?

1. Petro-chemicals
2. Metallic elements
3. Organic compounds
4. Natural fibers

Characteristics of Thermoplastics

Thermoplastics are characterized by linear molecular chains and weak secondary bonds, used for their ductility, low stiffness, and ease of manufacturing.

Structure of thermoplastics

• Thermoplastics are linear chain molecules with weak secondary bonds between the chains.
• The Making of the Modern World has an informative article on Polymers and intermolecular bonds

General characteristics include:

• ductile
• low stiffness – squishy water bottles for example
• easily injected into a mould
• can be reshaped after heating
• easily and cost effectively manufactured
  

What type of intermolecular bonds do thermoplastics have?

1. Weak secondary bonds
2. No intermolecular bonds
3. Strong covalent bonds

What are the general characteristics of thermoplastics?

1. Ductile
2. High stiffness
3. Cannot be manufactured cost-effectively
4. Easily reshaped after heating

Structure of thermosetting plastics

• Thermosets are linear chain molecules with strong primary bonds between adjacent polymer chains.
• This gives thermosets a rigid 3D structure.

Characteristics include:

• high stiffness
• higer strength than thermoplastics
• cannot be reheated and remoulded 

How does the 3D structure of thermosetting plastics compare to thermoplastics?

1. Amorphous
2. Flexible
3. Non-conforming
4. Rigid

Which of the following characteristics is true for thermosetting plastics?

1. Can be reshaped multiple times
2. Cannot be reheated and remoulded
3. Low stiffness
4. Lower strength than thermoplastics

What type of bonds do thermosetting plastics have between adjacent polymer chains?

1. Strong primary bonds
2. Weak secondary bonds
3. Covalent bonds
4. Van der Waals forces

Structure and Properties of Thermosetting Plastics

Thermosetting plastics have strong primary bonds creating a rigid structure, offering high stiffness and strength but cannot be remolded.

Challenges in Recycling and Disposal

Recycling of plastics is influenced by economic, technical, and logistical factors, and while thermoplastics can be easily recycled, thermosets pose more challenges.

Impact of Temperature on Thermoplastics

The process of recycling thermoplastics involves heating to break weak secondary bonds, allowing reshaping.

Key Definitions

Petrochemicals, Bio-plastics, Thermoplastics, Thermosetting plastics, Recycling, Primary bonds, Secondary bonds

forms.gle

(IB-- Question) Which plastic is most widely used in the production of water bottles?

1. Polyvinylchloride (PVC)
2. High impact polystyrene (HIPS)
3. Polyethylene terephthalate (PET)
4. Acrylonitrile butadiene styrene (ABS)

Outline why polypropylene (PP) is used as a material for a cell/mobile phone case.

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down your definition of this topic

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.