Chapter 27 – Infographic descriptions
Infographics used in Chapter 27
- 27.0a Sticky Science – The Chemistry of Superglue
- 27.0b The Myriad Uses of Stronger Than Steel Kevlar
- 27.0c Life in plastic(s): The chemistry of a Barbie doll
- 27.4a Today in Chemistry History – Teflon
- 27.4b A Guide to Common Household Plastics
- 27.5a What are the Olympics athletics tracks made of?
- 27.6a Chemistry History – Carothers, Condensation Polymerisation, & Nylon
- 27.7a What are Lego bricks made of, and why is treading on them so painful?
- 27.9a What’s your biodegradable coffee cup made of – and how biodegradable is it?
- 27.9b RealTimeChem Week: Turning carbon dioxide into useful plastics
27.0a Sticky Science – The Chemistry of Superglue
Superglue was accidentally discovered twice.
In 1942, cyanoacrylates discovered during WWII search for gun sight plastics, was discarded as it stuck to everything.
In 1951, cyanoacrylates are rediscovered during research looking for polymers for jet canopies.
Cyanoacrylates potential realized and developed into glue that eventually becomes available commercially in 1958.
The most commonly used cyanoacrylate in superglue is ethyl cyanoacrylates. Others can be used: methyl cyanoacrylate. Medical grade cyanoacrylates such as 2-octyl cyanoacrylate can be used to close wounds.
Read more about “Sticky Science – The Chemistry of Superglue [New tab]” by Andy Brunning / Compound Interest, CC BY-NC-ND
27.0b The Myriad Uses of Stronger Than Steel Kevlar
Kevlar (polyparaphenylene terephthalamide) was discovered in 1965 by Stephanie Kwolek. Polyparaphenylene terephthalamide has a density of 1.44g/cm3 , a tensile strength 5 times stronger then steel (qual weight basis). There are many varieties: Kevlar, Kevlar 29, Kevlar 49, Kevlar 149.
Kevlar is a polymer – a very long, chain-like molecule which is formed by the reaction of multiple smaller molecules called monomers. It has a high strength, the result of many strong intermolecular hydrogen bonds between the adjacent polymer molecules. Monomers: 1,4-Phenylene-Diamine and Terephthaloyl Chloride.
The uses of Kevlar:
- Mobile phones: used for back casings of some mobile phone.
- Ping pong paddles: added to paddles to increase bounce and reduce weigh.
- Formula 1 cards: used for the bodywork and petrol tanks.
- Body armour: used for helmets, face masks and ballistic vests.
- Automobile types: used as a reinforcement material for some car tires and brake pads.
- Protective gloves: Used in the manufacture of gloves designed to protect form cuts and heat.
- Bicycle tires: Used as inner lining to prevent punctures.
- Fighter jets: used in manufacture of panels and wings.
- Fireproof clothing: Kevlar offers protection from high temperatures – useful for firefighters.
Read more about “The Myriad Uses of Stronger Than Steel Kevlar [New tab]” by Andy Brunning / Compound Interest, CC BY-NC-ND
27.0c Life in plastic(s): The chemistry of a Barbie doll
The head is made of polyvinyl chloride (PVC) mixed with plasticized to make it more flexible. The hair is usually made of polyvinylidene dichloride (PVDC) and other polymers including nylon and polypropylene.
Historically, Barbie doll arms were made of PVC, but today Barbie’s arms are made of ethylene-vinyl acetate, which is soft and flexible.
The torso of early versions of Barbie was made out of PVC and in the mid-1960s to mid-1970s it was low density polyethylene (LDPE). Today, the torso is made of acrylonitrile butadiene styrene (ABS) – the same as Lego bricks.
The legs are made of PVC, with bend-leg armatures made of polypropylene.
Read more about “ Life in plastic(s): The chemistry of a Barbie doll [New tab]” by Andy Brunning / Compound Interest, CC BY-NC-ND
27.4a Today in Chemistry History – 4th February – Patent Issued for Teflon (1941)
Teflon is the brand name for polytetrafluoroethene (PTFE). It’s a white, waxy substance, and was actually created by accident by Roy Plunkett in 1938. During research on new refrigerants, the tetrafluoroethene Plunkett was using was accidentally polymerised.
Tetrafluoroethene, CF2=CF2; polytetrafluoroethene, (CF2CF2)n
Image of Teflon pan
How does it work? Teflon’s non-stick properties are in part due to the strength of its carbon-fluorine bonds, which are chemically inert. Additionally, due to the fluorine atoms, the intermolecular forces between PTFE and other molecules are very weak.
Is Teflon safe? During appropriate use, Teflon does not reach the temperatures required for it to degrade. However, if the coating is overheated the polymer can begin breaking down, and the fumes produced can cause flu-like symptoms. At present, the long term effects of human exposure to these fumes are still largely unknown.
Melting Point: 327oC, Recommended Max Safe Use Temperature: 260oC.
Read more about “Chemistry History: Teflon & Non-Stick Pans [New tab]” by Andy Brunning / Compound Interest, CC BY-NC-ND
27.4b A Guide to Common Household Plastics
Plastics are substances called polymers – these are long, chain-like molecules, formed from many smaller molecules. We use a number of different plastics in our day-to-day lives. This graphic looks at uses of the most frequently encountered, along with their chemical structures.
| Abbreviation | Name | Structure | Details |
|---|---|---|---|
| PE | Polyethene | (CH2CH2)n | Polyethene is the most produced plastic, and comes in a number of different forms, including high density polyethene (HDPE) and low density polyethene (LDPE). It is used in plastic bags, bottles, plastic films, piping, and toys. It is not biodegradable. |
| PP | Polypropene | (CH2CHCH3)n | Polypropene is particularly resistant to heat, physical damage, and corrosion. As a consequence, it is commonly used in food containers, carpets and rugs, ropes, plastic furniture, and piping. It’s also used to make items for medical or laboratory uses. |
| PVC | Polyvinylchloride | (CH2CHCl)n | PVC comes in both rigid and flexible forms. In its rigid form, it can be used for window and door frames, piping, and bank cards. By adding plasticisers, a more flexible form can be obtained, which is used in electric cable insulation, and as a rubber substitute. |
| PET | Polyethylene terephthalate | (OCOC6H4COOCH2CH2)n | PET is a lightweight polymer, and comes in forms of varying rigidity. It’s commonly used for plastic drink bottles, and also for clothing fibres (where it’s often referred to generally as ‘polyester’). Additionally, it’s used in ready meal packing and tapes. |
| PS | Polystyrene | (CH2CHC6H5)n | Polystyrene is one of the most widely used plastics. It’s used in its solid form to produce plastic cutlery, CD cases, and disposable razors, whilst as a foam it’s used in packing materials, building insulation, and foam containers for food and drink. |
| PTFE | Polytetrafluoroethene | (CF2CF2)n | PTFE’s well-known brand name is Teflon. It’s a very unreactive polymer, and is used in non-stick coatings on cookware. Gore-tex fabrics also contain PTFE-based fibres. It also has applications as a lubricant, and as insulation for electric wires and cables. |
| PA | Nylon (polyamide) | (NH(CH2)6NHCO(CH2)4CO)n | Nylon actually refers to a family of polymers; nylon 6,6 is shown here. It was originally intended as a synthetic silk replacement, for military applications such as parachutes. Today, it is used in clothing, guitar strings and fishing lines. |
| PU | Polyurethane | (RNHCOOROCONH)n | Polyurethanes are also a family of polymers; the R group in the structure above varies. Their uses include foam seating, for both furniture and cars, non-latex condoms, shoe soles, football coatings, skateboard and roller-blade wheels, and some varnishes. |
Read more about “A Guide to Common Household Plastics [New tab]” by Andy Brunning / Compound Interest, CC BY-NC-ND,
27.5a What are the Olympics athletics tracks made of?
The 2020 Olympics use a specially designed track surface made from rubber (elastomeric polymer), which returns to its original shape when it’s deformed. Other types of running track bind rubber particles with a polyurethane polymer over an asphalt base, and these track surfaces are commonly used for school and community tracks.
Top layer is embossed surface: The texture of the track surface improves slip resistance and traction, while the honeycomb layer of the bottom layers also aids shock absorption. Non-directional tessellation helps water drain from the surface and enhances grip.
Second layer is vulcanised rubber: Vulcanisation (treatment of rubber with sulfur) increases rubber’s rigidity by forming crosslinks between rubber polymer chains.
Third layer is rubber granules embedded in the layers form bonds with the vulcanised rubber matrix, improving elasticity and shock absorption.
Bottom later are shaped like elongated honeycombs, which deform in three directions to help with shock absorptions and the air cells compress on impact allowing athletes to bounce off the surface.
Read more about “What are the Olympics athletics tracks made of? [New tab]” by Andy Brunning / Compound Interest, CC BY-NC-ND
27.6a Chemistry History – Carothers, Condensation Polymerisation, & Nylon
Wallace was born 27 April 1896 and died 29 April 1937. Carothers invented nylon using condensation polymerization, he also had a hand in inventing neoprene. Nylon is a polyamide, a type of condensation polymer. Condensation polymerization is when many monomers (smaller molecules) join together to make a polymer, with a small molecule, often water, being lost. A general scheme for making polyamides is shown.
Nylon 6,6 is made using monomers (hexanedioic acid and 1,6-Dianinohexane). Carothers’ group first created nylon using these monomers in 1935.
Read more about “Chemistry History – Carothers, Condensation Polymerisation, & Nylon [New tab]” by Andy Brunning / Compound Interest, CC BY-NC-ND,
27.7a What are Lego bricks made of, and why is treading on them so painful?
Up until 1963, cellulose acetate was used to make Lego bricks/parts. Lefo bricks are now made of acrylonitrile butadiene styrene (ABS), which warps and fades less.
Lego is made by using ABS granuales and adding macrolex dyes for colour, and then heating it to 230 degrees Celsius (450 degree Fahrenheit). The melted plastic is then fed into molds. ABS is opaque, so a polycarbonate polymer has to be used for transparent Lego parts. For leaves, bushes and trees, Lego has recently started using polyethene derived from sugar cane. Tires and elastic materials are made from styrene butadiene styrene (SBS).
In 2014, more the 60 billion Lego pieces were made.
Read more about “What are Lego bricks made of, and why is treading on them so painful? [New tab]” by Andy Brunning / Compound Interest, CC BY-NC-ND
27.9a What’s your biodegradable coffee cup made of – and how biodegradable is it?
Common biopolymers:
- Polyactic acid (PLA): Obtained from fermented plant starch from corn, cassava, sugar cane or sugar beet.
- Polyhydroxyalkanoates (PHAs): Extracted from bacteria, which produce it via the fermentation of sugar or lipids.
- Thermoplastic starches (TPS): Startches from plant materials are heated with water then mixed with plasicisers or other polymers.
Everyday use of biopolymers:
- Biodegradable coffee cups are paper cups with PLA lining to make the paper waterproof.
- PLA has the second largest production volume of any biopolymer (behind TPS). It is also used in plastic films, bottles and food containers.
- PLA and TPS both find use in the manufacture of plastic cutlery that’s biodegradable.
- TPS is also used in food waste bags and some magazine wrappers. PHAs have fewer uses, but have medical uses such as in surgical sutures.
Advantages and disadvantages:
- Use of bioplastics is increasing, but as of 2018 they still account for less then 1% of the global plastic market: 333 million tons of conventional plastics and 2.11 million tons of biodegradable and bioplastics.
- Compostable plastics need specific conditions to break down – and take longer to do so in a landfill instead of being recycled, however they still break down faster then conventional plastics.
- Biodegradable plastics are more expensive than plastics derived from fossil fuels on weight basis and require land to grow raw materials, but the greenhouse gas emissions associated with their production are lower.
Read more about “What’s your biodegradable coffee cup made of – and how biodegradable is it? [New tab]” by Andy Brunning / Compound Interest, CC BY-NC-ND
27.9b RealTimeChem Week: Turning Carbon Dioxide into Useful Plastics
Levels of carbon dioxide in our atmosphere have reach an all-time high. In addition to finding methods to reduce emissions it is important to utilize the waste carbon dioxide in our environment. One way is to use catalysts to incorporate carbon dioxide into plastics.
Catalysts facilitate reaction between carbon dioxide and small reactive molecules called epoxides. This reaction makes a long chain of (n) repeat molecules called a copolymer, which are used to make plastic products. Captured waste carbon dioxide can be used as a starting point and up to 40% of this used is incorporated into the final polymer.
Most prevalent application of polymers produced is incorporating them into polyurethanes. Polyurethanes are a family of plastics with a range of applications including: memory foam mattresses, house insulation, shoe soles, and sports equipment. Using this method of production is more environmentally sustainable.
By incorporating waste carbon dioxide already present in the environment into everyday plastics it increases environmental sustainability and decreases our dependency on fossil fuels.
Based on research materials provided by Econic Technologies: Catalysts for Polymerisation.
Read more about “RealTimeChem Week: Turning Carbon Dioxide into Useful Plastics [New tab]” by Andy Brunning / Compound Interest, CC BY-NC-ND
Attribution & References
Compound Interest infographics are created by Andy Brunning and licensed under CC BY-NC-ND
Except where otherwise noted, content on this page has been created as a textual summary of the infographics used within our OER. Please refer to the original website (noted below each description) for further details about the image.
