chemistry

PolyDADMAC

PolyDADMAC 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 PolyDADMAC rather than just read about it. In short: Polydiallyldimethylammonium chloride (shortened polyDADMAC or polyDDA), also commonly polyquaternium-6, is a homopolymer of diallyldimethylammonium chloride (DADMAC). The molecular weight of polyDADMAC is typically in the range of hundreds of thousands of grams per mole, and even up to a million for some products.

Key takeaways

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

Reference excerpt

Polydiallyldimethylammonium chloride (shortened polyDADMAC or polyDDA), also commonly polyquaternium-6, is a homopolymer of diallyldimethylammonium chloride (DADMAC). The molecular weight of polyDADMAC is typically in the range of hundreds of thousands of grams per mole, and even up to a million for some products. PolyDADMAC is usually delivered as a liquid concentrate having a solids level in the range of 10 to 50%. It is a high charge density cationic polymer. The charge density makes it well suited for flocculation. Actually, pDADMAC or DMDAAC, is used as a coagulant - a charge neutralization process that precedes flocculation.

History PolyDADMAC polymers were first prepared and studied in 1957 by Professor George Butler at the University of Florida. It was remarkable as it was soluble in water in contrast at the time to other known synthetic polymers formed by polymerization of monomers containing more than one vinyl functionality. The structure and reaction path was determined in 2002 with NMR studies. Much of what we know about pDADMAC in water treatment and personal care is from Jerry Boothe of Calgon Corporation.

Synthesis The monomer DADMAC is formed by reacting two equivalents of allyl chloride with dimethylamine. PolyDADMAC is then synthesized by radical polymerization of DADMAC with an organic peroxide used as a catalyst. Two polymeric structures are possible when polymerizing DADMAC: N-substituted piperidine structure or N-substituted pyrrolidine structure. The pyrrolidine structure is favored.

Applications

Effluent treatment PolyDADMAC is used in waste water treatment as a primary organic coagulant which neutralizes negatively charged colloidal material and reduces sludge volume compared with inorganic coagulants.

Pulp and paper industry PolyDADMAC is used for controlling disturbing substances in the papermaking process. It provides superior fixing of pitch from mechanical pulp and of latex from coated broke. Used in the short circulation of a paper mill to enhance retention and dewatering. In addition, it can be used to improve the efficiency of disk filters and flotators, and for cationization of fillers to provide maximal filler retention.

Water purification PolyDADMAC is used as a coagulant in water purification. It is effective in coagulating and flocculating inorganic and organic particles such as silt, clay, algae, bacteria and viruses. At high concentrations the organic polymer can remove natural organic matter such as humic and fulvic acids resulting in fewer disinfection byproduct precursors and less color.

References

Illustrations

Worked examples

Example 1 — a first encounter with PolyDADMAC

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

In research: PolyDADMAC 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 PolyDADMAC 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: PolyDADMAC is common in secondary-school and first-year university syllabi. It links to neighbouring topics Organic polymers, Quaternary ammonium compounds, Water treatment, so understanding it makes those chapters shorter.
In everyday life: Look for PolyDADMAC 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 PolyDADMAC in 20 minutes

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

Frequently asked questions

What is PolyDADMAC in simple terms?

Why does PolyDADMAC 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 PolyDADMAC?

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 PolyDADMAC.