Questions tagged [polymers]

For questions about synthetic or natural polymers, their chemical or physical properties, and their synthesis, etc.

A polymer is a large molecule, or macromolecule, composed of many repeated subunits. Because of their broad range of properties, both synthetic and natural polymers play an essential and ubiquitous role in everyday life. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass relative to small molecule compounds produces unique physical properties.

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Is there any chemical that can destroy PTFE or Teflon?

Polytetrafluoroethylene was discovered by accident. It now is an important material in the industry mainly because of its extremely high bonding energy, which prevents corrosion, halts reaction, and reduces friction (yeah carbon-fluorine bonds!) And…
HyperLuminal
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Why isn't nylon as strong as kevlar?

Why is Kevlar stronger than nylon? They both contain Hydrogen bonding and should have equal strength but this is not the case instead Kevlar is fire resistant. What makes it stronger. Greater hydrogen bonds?!
Asad
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Living-cationic vs cationic polymerization

To my understanding, cationic polymerization is a type of living polymerization but my teacher's notes and Wikipedia seem to suggest they're different. I can't see the difference. The same goes for anionic polymerization. From what I've studied so…
CHM
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Are there any general chemical rules for choosing initiators for a polymerization reaction?

I'm working with some very basic free-radical initiated polymerization reactions. For the most part, I just follow a recipe I'm given (by a member of my group or the broader literature), it works, and I don't worry too much about the chemistry of…
Colin McFaul
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Has a carbon analogue of poly(dimethylsiloxane) been synthesized?

Consider poly(dimethylsiloxane) (PDMS), a member of the family of silicone polymers: Now, imagine its carbon analogue: I've not been able to find any evidence that this carbon analogue has been experimentally prepared. Searching for…
hBy2Py
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How many molecules are there typically in items made of plastics?

In objects made of plastic (and other polymers), how many molecules would one generally expect to find? Intuitively, it seems like, say, a plastic shopping bag or PET bottle couldn't be a single molecule, but on the other hand, that's one of the…
Williham Totland
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Why isn’t there LDPP, HDPP?

Unlike polyethylene that there are LDPE, HDPE, or LLDPE, when it comes to polypropylene the issue becomes about copolymer (homo/ copo/ block copolymer) or location of methyl group (isotactic/ atactic/ syndiotactic)? Why does polypropylene not have…
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Repeating unit of poly lactic acid (PLA)

Which repeating unit for poly lactic acid (PLA) is correct, picture 1 or picture 2? and I read somewhere that in polymerization, acids give $\ce{OH}$ and alcohol gives $\ce{H}$, creating water. According to this explanation, picture number 2 is…
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What materials reversibly swell up slightly when in a moist environment?

I am aware that some "Super Absorbent Polymers" can swell up enormously when they absorb water. However, I am looking for a material which swells up (maybe about 30% to 100%) when in a moist environment, and which will contract again when moved to a…
Rocketmagnet
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Finding the repeating unit of polymerisation given two constituent molecules

The compounds $\ce{H2NCH2CH2NH2}$ and $\ce{HOOCCH2COOH}$ react to form a polymer. What is the structure of the repeating unit of the polymer? A.…
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How much UV lamp power is needed to initiate radical polymerization?

I'm looking to purchase a UV lamp for initating some radical polymerizations. Is a hand lamp like the type for examining TLC plates (5-10W, like this) enough power to do this, or do I have to buy something a lot more expensive? In my case, I'm…
chipbuster
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Are there different types of melamine resin?

Background I have a little knowledge of chemistry. I was talking to a sales rep from a cleaning supplies company. They sell a scrub sponge that looks and functions just like Mr. Clean Magic Eraser. The sales rep was trying to scare me by saying that…
toxalot
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What makes polyimides good polymers for fibers?

Wikipedia says polyimides are known for “thermal stability, good chemical resistance, excellent mechanical properties”. I guess that's why they're used industrially as fibers. But where do they derive there good stability (thermal, mechanical and…
F'x
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Alginate nanoparticles

I want to produce alginate nanoparticles from NaAlg. I choosed nebulizing NaAlg solution into $\ce{CaCl2}$ solution but 2% (m/v) NaAlg solution is quite viscous. What should I do to make it inviscid?
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How do nylon and polypropylene blend together in the production of a toothbrush?

Why is nylon (nylon 6) and polypropylene chosen together to make a toothbrush? Specifically, how are they blended together during the production process, and what determines their price?
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