chemistry

Styrofoam

Styrofoam 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 Styrofoam rather than just read about it. In short: Styrofoam is a brand of closed-cell extruded polystyrene foam (XPS), manufactured to provide continuous building insulation board used in walls, roofs, and foundations as thermal insulation and as a water barrier. This material is light blue in color and is owned and manufactured by DuPont.

Key takeaways

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

Reference excerpt

Styrofoam is a brand of closed-cell extruded polystyrene foam (XPS), manufactured to provide continuous building insulation board used in walls, roofs, and foundations as thermal insulation and as a water barrier. This material is light blue in color and is owned and manufactured by DuPont. DuPont also has produced a line of green and white foam shapes for use in crafts and floral arrangements.

The term styrofoam is argued to have become a genericized trademark; as it is often used in the United States as a colloquial term to refer to expanded (not extruded) polystyrene foam (EPS). Outside the United States, EPS is most commonly referred to as simply "polystyrene" with the term "styrofoam" being used in its capacity to describe all forms of extruded polystyrene, not just the Dupont brand itself. Polystyrene (EPS) is often used in food containers, coffee cups, and as cushioning material in packaging. Styrofoam is, however, a denser material than EPS and is more commonly suited to tasks such as thermal insulation. Additionally, it is moderately soluble in many organic solvents, cyanoacrylate, and the propellants and solvents of spray paint.

History In the 1940s, researchers, originally at Dow's Chemical Physics Lab, led by Ray McIntire, found a way to make foamed polystyrene. They rediscovered a method first used by Swedish inventor Carl Georg Munters, and obtained an exclusive license to Munters's patent in the United States. Dow found ways to adapt Munters's method to make large quantities of extruded polystyrene as a closed cell foam that resists moisture. The patent on this adaptation was filed in 1947.

Uses Styrofoam has a variety of uses. Styrofoam is composed of 98% air, making it lightweight and buoyant. DuPont produces Styrofoam building materials, including varieties of building insulation sheathing and pipe insulation. The claimed R-value of Styrofoam insulation is approximately 5 °F⋅ft2⋅h/BTU for 1 inch thick sheet. Styrofoam can be used under roads and other structures to prevent soil disturbances due to freezing and thawing. DuPont also produces Styrofoam blocks and other shapes for use by florists and in craft products. DuPont insulation Styrofoam has a distinctive blue color; Styrofoam for craft applications is available in white and green.

Environmental issues The EPA and International Agency for Research on Cancer reported limited evidence that styrene is carcinogenic for humans and experimental animals, meaning that there is a positive association between exposure and cancer and that causality is credible, but that other explanations cannot be confidently excluded.

See also List of generic and genericized trademarks National Inventors Hall of Fame Resin identification code Structural insulated panel

References

Illustrations

Worked examples

Example 1 — a first encounter with Styrofoam

Start with the simplest possible case. Write down what Styrofoam 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 Styrofoam 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 Styrofoam 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 Styrofoam

In research: Styrofoam 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 Styrofoam 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: Styrofoam is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1941 in technology, American inventions, Brand name materials, so understanding it makes those chapters shorter.
In everyday life: Look for Styrofoam 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Styrofoam in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Styrofoam 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 Styrofoam out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Styrofoam in simple terms?

Why does Styrofoam 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 Styrofoam?

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 Styrofoam.