chemistry

Polyaryletherketone

Polyaryletherketone is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Polyaryletherketone rather than just read about it. In short: Polyaryletherketone (PAEK) is a family of semi-crystalline thermoplastics with high-temperature stability and high mechanical strength whose molecular backbone contains alternately ketone (R-CO-R) and ether groups (R-O-R). The linking group R between the functional groups consists of a 1,4-substituted aryl group.

Key takeaways

Polyaryletherketone belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Polyaryletherketone to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Polyaryletherketone from memory before moving on to harder problems.

Reference excerpt

Polyaryletherketone (PAEK) is a family of semi-crystalline thermoplastics with high-temperature stability and high mechanical strength whose molecular backbone contains alternately ketone (R-CO-R) and ether groups (R-O-R). The linking group R between the functional groups consists of a 1,4-substituted aryl group.

Properties PAEK has a continuous operating temperature of 250 °C (482 °F) and under short-term loads can function up to 350 °C (662 °F). When burned it has the least toxic and corrosive fumes. It also has a low heat output when burned, so it qualifies for use in interior aviation applications. It also has good overall chemical resistance. It has a tensile strength of 85 MPa (12,300 psi) and a Young's modulus of 4,100 MPa (590,000 psi). Its yield strength is 104 MPa (15,100 psi) at 23 °C (73 °F) and 37 MPa (5,400 psi) at 160 °C (320 °F). It does not break in an un-notched Izod impact test.

Chemistry PAEK plastics are characterized by phenylene rings that are linked via oxygen bridges (ether and carbonyl groups (ketone)). The ratio and sequence of ether to ketones mainly affects the glass transition temperature and melting point of the polymer. It also affects its heat resistance and processing temperature. The higher the ratio of ketones the more rigid the polymer chain, which results in a higher glass transition temperature and melting point. The processing temperatures can range from 350 to 430 °C. Plastics that fall within this family include:

PEK PEEK PEKK PEEKK PEKEKK (polyetherketoneetherketoneketone)

Production PAEKs can be produced in two ways, one is called the nucleophilic route and the other is called the electrophilic route. The nucleophilic route has the formation of ether linkages in the polymerization step. The electrophilic route has the formation of carbonyl bridges during the polymerization step. It can be processed using all of the typical thermoplastic processes, such as injection molding, extrusion, compression molding, additive manufacturing, and transfer molding.

Applications One major engineering application is oil drilling components, such as seals, compressor rings, valve parts, gears, bearings, and wire coatings. It is also used in the chemical pump industry because it can withstand the temperature, stress, and has the corrosion resistance. In the automotive industry it is used to make gears and thrust bearings in transmissions. Due to its excellent resistance to hydrolysis it is used in medical devices because it does not break down when sterilized. PEKEKK is used to make surgical implants, such as artificial hips.

References

Bibliography Rosato, Dominick V.; Rosato, Donald V. (2004), Plastic product material and process selection handbook, Elsevier, ISBN 978-1-85617-431-2. Salamone, Joseph C. (1999), Concise polymeric materials encyclopedia, CRC Press, ISBN 978-0-8493-2226-6. Salamone, Joseph C. (1996), Salamone, Joseph C. (ed.), Polymeric materials encyclopedia, vol. 4, CRC Press, ISBN 978-0-8493-2470-3.

Further reading Kemmish, David (2010), Update on the Technology and Applications of PolyArylEtherKetones (PAEKs), iSmithers, ISBN 978-1-84735-408-2.

Worked examples

Example 1 — a first encounter with Polyaryletherketone

Start with the simplest possible case. Write down what Polyaryletherketone claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Polyaryletherketone before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Polyaryletherketone ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Polyaryletherketone

In research: Polyaryletherketone appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Polyaryletherketone in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Polyaryletherketone is common in secondary-school and first-year university syllabi. It links to neighbouring topics Organic polymers, Polyethers, Thermoplastics, so understanding it makes those chapters shorter.
In everyday life: Look for Polyaryletherketone outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Polyaryletherketone in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Polyaryletherketone means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Polyaryletherketone out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Polyaryletherketone in simple terms?

Why does Polyaryletherketone matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Polyaryletherketone?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Polyaryletherketone.