chemistry

Ladder polymer

Ladder polymer 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 Ladder polymer rather than just read about it. In short: In chemistry, a ladder polymer is a type of double stranded polymer with the connectivity of a ladder. In a typical one-dimensional polymer, e.g. polyethylene and polysiloxanes, the monomers form two bonds, giving a chain.

Key takeaways

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

Reference excerpt

In chemistry, a ladder polymer is a type of double stranded polymer with the connectivity of a ladder. In a typical one-dimensional polymer, e.g. polyethylene and polysiloxanes, the monomers form two bonds, giving a chain. In a ladder polymer the monomers are interconnected by four bonds. Inorganic ladder polymers are found in synthetic and natural settings. Ladder polymers are a special case of cross-linked polymers because the crosslinks exist only with pairs of chains. According to one definition, a ladder polymer, adjacent rings have two or more atoms in common.

Organic ladder polymers Organic ladder polymers are of interest because they can exhibit exceptional thermal stabilities and the conformation of the subunits is constrained. Because they are less flexible, their processing can be challenging. An early example was derived from condensation of the 1,2,4,5-tetraaminobenzene with naphthalenetetracarboxylic dianhydride. Poly(benzimidazobenzophenanthroline) (BBL) is a conjugated ladder polymer. Its backbone is composed of aromatic rings and the ladder structures enable the uninterrupted polymer chains with periodic linkages. However, conjugated ladder polymers additionally contain pi conjugation via strong pi-pi stacking interactions and charge transport. Traditionally, p-typed doped poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is used as conductive polymers, but BBL doped with poly(ethyleneimine) (PEI) can provide a n-type doped conductive properties for fabricating high-performance organic electronic devices. BBL's glass transition temperature (Tg) is estimated to be around 500 C based on differential scanning calorimetry (DSC) measurements. BBL is stable at higher temperatures. In addition to this, the stress-strain curves of BBL fibers were observed to be very high compared to other semiconductor fibers with a value around 105.8 MPa with the highest BBL polymer concentration.

Inorganic and organometallic ladder polymers Some polysilicates are ladder polymers. One example is provided by the mineral tremolite. In the area of coordination chemistry, the ladder structure is seen in some coordination polymers. Illustrative is the polymer [CuI(2-picoline]n. When the 2-picoline is replaced by a tertiary phosphine, it forms a tetrameric cubane-type cluster, [CuI([[PR3]]4 (R = organic group_. In both cases, the Cu(I) centers adopt tetrahedral molecular geometry.

References

Illustrations

Worked examples

Example 1 — a first encounter with Ladder polymer

Start with the simplest possible case. Write down what Ladder polymer 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 Ladder polymer 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 Ladder polymer 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 Ladder polymer

In research: Ladder polymer 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 Ladder polymer 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: Ladder polymer is common in secondary-school and first-year university syllabi. It links to neighbouring topics Polymer chemistry, so understanding it makes those chapters shorter.
In everyday life: Look for Ladder polymer 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 Ladder polymer in 20 minutes

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

Frequently asked questions

What is Ladder polymer in simple terms?

Why does Ladder polymer 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 Ladder polymer?

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 Ladder polymer.