chemistry

Polyvinylidene chloride

Polyvinylidene chloride 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 Polyvinylidene chloride rather than just read about it. In short: Polyvinylidene chloride, or polyvinylidene dichloride (PVDC), is a homopolymer of vinylidene chloride. History Ralph Wiley accidentally discovered polyvinylidene chloride polymer in 1933.

Key takeaways

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

Reference excerpt

Polyvinylidene chloride, or polyvinylidene dichloride (PVDC), is a homopolymer of vinylidene chloride.

History Ralph Wiley accidentally discovered polyvinylidene chloride polymer in 1933. At the time he was a college student who worked part-time at Dow Chemical lab as a dishwasher. While cleaning laboratory glassware, he came across a vial he could not scrub clean. Dow researchers made this material into a greasy, dark green film, first called "Eonite" and then "Saran". Ralph Wiley went on to become one of Dow Chemical's research scientists and invent and develop many plastics, chemicals and production machines. The military sprayed Saran on fighter planes to guard against salty sea spray, and carmakers used it for upholstery. Dow later devised a formulation of polyvinylidene chloride free of unpleasant odour and green colour. The most well known use of polyvinylidene chloride came in 1953, when Saran Wrap, a plastic food wrap, was introduced. In 2004, however, the formula was changed to low-density polyethylene due to environmental concerns about its chlorine content and other disadvantages.

Properties It is a remarkable barrier against water, oxygen, and aromas. It has a superior chemical resistance to alkalis and acids, is insoluble in oil and organic solvents, has a very low moisture regain and is impervious to mold, bacteria, and insects. It is soluble in polar solvents. Above 125 °C, it decomposes to produce HCl.

Disadvantages While extremely useful as a food packaging agent, the major disadvantage of polyvinylidene chloride is that it will undergo thermally induced dehydrochlorination at temperatures very near to processing temperatures. This degradation easily propagates, leaving polyene sequences long enough to absorb visible light and change the color of the material from colorless to an undesirable transparent brown (unacceptable for one of polyvinylidene chloride's chief applications: food packaging). Therefore, there is a significant amount of product loss in the manufacturing process, which increases production and consumer costs.

Fiber types Saran fiber is produced in monofilament, multifilament-twist, and staple fiber forms. It is also available in thermochromic (color changing) and luminescent (glow in the dark) fibers.

Uses

Packaging Polyvinylidene chloride is applied as a water-based coating to films made of other plastics, such as biaxially-oriented polypropylene (BOPP) and polyethylene terephthalate (PET). This coating increases the barrier properties of the film, reducing the permeability of the film to oxygen and flavours and thus extending the shelf life of the food inside the package. It can also impart a high-gloss finish, which may be aesthetically pleasing and also provides a high degree of scuff resistance if applied over print.

Other In household settings, PVDC is used in cleaning cloths, filters, screens, tape, shower curtains, and garden furniture. Industrially, it is used in screens, artificial turf, waste-water treatment materials, and underground materials. PVDC is also used in doll hair, stuffed animals, fabrics, fishnet, pyrotechnics, and shoe insoles. It was used in special photographic film.

Trademarks (producers)

Saran TC and Saran LS (Asahi-Kasei) (formerly) Saran Wrap and Saranex (Dow Chemical) Ixan and Diofan (SolVin) SK Saran

References

External links Wiley mini-bio Textile Fibre Database

Worked examples

Example 1 — a first encounter with Polyvinylidene chloride

Start with the simplest possible case. Write down what Polyvinylidene chloride 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 Polyvinylidene chloride 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 Polyvinylidene chloride 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 Polyvinylidene chloride

In research: Polyvinylidene chloride 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 Polyvinylidene chloride 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: Polyvinylidene chloride is common in secondary-school and first-year university syllabi. It links to neighbouring topics Thermoplastics, Vinyl polymers, so understanding it makes those chapters shorter.
In everyday life: Look for Polyvinylidene chloride 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Polyvinylidene chloride” →

Affiliate

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

How to study Polyvinylidene chloride in 20 minutes

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

Frequently asked questions

What is Polyvinylidene chloride in simple terms?

Polyvinylidene chloride, or polyvinylidene dichloride (PVDC), is a homopolymer of vinylidene chloride. History Ralph Wiley accidentally discovered polyvinylidene chloride polymer in 1933.

Why does Polyvinylidene chloride 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 Polyvinylidene chloride?

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 Polyvinylidene chloride.