Questions tagged [polymers]

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

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0answers
9 views

hydrodynamic thickness of polymer vs. concentration of electrolyte?

I've measured the hydrodynamic thickness of a NaPSS layer on polystyrene latex and plotted it against the concentration of the supporting electrolyte, NaCl. My graph shows a general decrease in ...
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16 views

Does PEO particle size decrease when dissolved in water?

I am looking to make metallic ink for inkjet printing and using PEO 1 wt% (MW ~600,000) as a binder. The print head I am hoping to use has a nozzle diameter of 80 microns. The metal powder dispersed ...
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Is the concept of a “self cleaning” banknote plausible?

Although in 2020 there is a big movement of bankers marketers to lean the public towards cashless society, cash in the form of banknotes is still used in many if not most countries. Cash banknotes ...
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1answer
48 views

Is terylene a copolymer?

Terylene is a polyester made from terephthallic acid and ethylene glycol. Even though we use two reagents, they undergo esterification to give bis(2-hydroxyethyl) terephthalate (monomer) which then ...
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1answer
45 views

Why fibres are strong only in one direction? [closed]

Why fibres are strong only in the direction they are oriented?Why they break if we pull at right angle to their orientation? Here each blue line represents combination of polymeric chains.
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20 views

PEO dissolved in deionized water and then cooled

I am looking to dissolve PEO (Mw ~ 300,000) that has a melting point of around 60 degrees C. I am planning on heating the DI water to 50 degrees and gradually dissolve the PEO in. However, if I let ...
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2answers
73 views

Acetone-resistant clear plastic

Is there a plastic that's clear, acetone resistant, and ideally sold in sheet stock that's ~1/8" or 1/4" thick? Both acrylic and polycarbonate are out, they turn cloudy on contact with acetone. I ...
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0answers
24 views

Impregnating polyethylene with oil using pressure cooker?

I have some polyethylene spiral wrap that I'm hoping to impregnate with citrus oil as an animal deterrent. Wikipedia says that polyethylene plastic will pass through "flavourings" fairly easily. It's ...
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1answer
53 views

Polymers which are miscible in oil

Can someone suggest me a list of polymers or some paper where I may find polymers that are soluble in oils like silicon oil, mustard oil, coconut oil, bean oil or petroleum ether, etc.?
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37 views

pH responsive polymer which is immiscible in water?

Can anyone suggest a pH-responsive polymer, which is immiscible in water (polar solvent) but miscible in oil (e.g vegetable oil)? I want to study the change in the density of such polymers when they ...
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12 views

Temperature dependence of rubber elastic modulus

Why does the elastic modulus of rubber decrease with temperature? I read the article on rubber elasticity and it showed that modulus is proportional to temperature. But I want to know why( intuitively ...
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32 views

How do you determine if a compound can go through addition polymerisation

For a polymer to form from a monomer, the monomer requires open bonds to attach itself to another monomer. Logically for me, it requires a double bond so I would go for answer C. But can the benzene ...
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1answer
33 views

Does clove oil/eugenol interact with nylon type plastics?

So I am aware that the eugenol in clove oil readily melts #6 type plastic (polystyrene). Polypropylene has a higher resistance, while HDPE type plastics seem to have the highest resistance. My main ...
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42 views

Why upon melting of PEO between crossed polars colours appear?

Crystalline PEO when under crossed polars shows distinct Maltese cross pattern. Being birefringent, when polymer crystal align with the polarizer or analyser it shows extinction regions (effect known ...
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5 views

Copolymerization regioselectivity

When undergoing copolymerization via free radical mechanism Buna-N forms a certain way. Actual product and possible products Can we predict which of the products will be formed based on the ...
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23 views

Difference between Ziegler–Natta method and Phillips method [closed]

I have to compare the similarities and differences between the Zieglerr–Natta method and Phillips method of producing polyethylene. However, the only difference I can find is the difference in ...
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2answers
86 views

Why polyethylene (PE), wool (polyamide) and cotton (cellulose) burnt with different smells, while they just product CO2 (and N2)?

Both PE and cotton produce CO2, but they distinctly have different smells while being burnt (Burning PE has smell of candle wax, while burning cotton’s smell is like burning leaves). Wool produces CO2 ...
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77 views

What does it mean “polyester doesn't breathe”?

Often people say buy a cotton shirt because cotton "breathes" but polyester doesn't. (i.e. it makes you hot sweaty). What is the scientific meaning behind this? How does polyester trap the heat more ...
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2answers
56 views

What does bulk mean when talking about polymers? [closed]

I recently read a paper by Lyulin et al. [1] where they talk about thin films and bulk polymers, I just don't quite understand what they mean by "bulk". Can someone please explain? References ...
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1answer
81 views

Polystyrene properties after dissolved by acetone

Polystyrene plastic can be dissolved in acetone. I would like to understand: If the dissolved polystyrene will take-out of the acetone and becomes solid again (after all the acetone evaporates), will ...
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0answers
18 views

Cyclohexane as a Solvent

I was wondering, why is cyclohexane used as a solvent in the synthesis of nylon. Typically, I see it being used to dissolved adipose chloride, but why is this the case?
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15 views

Super-absorbent Polymers [closed]

I want to cast a cube out of super-absorbent powder (Fake Snow) for an art piece, and make it become shapeless by gradually exposing it to water over 7 days. I have 2 questions: What is the best type ...
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0answers
21 views

How to get rid needle clogging on electrospinning of PLA/PCL/PMMA/Collagen?

For my thesis research, I dissolved PLA and PCL in chloroform: methanol (3:1), PMMA (350.000 MW, 13 wt%) in acetone, and collagen in acetate acid--and then, I mixed them together. The problem is when ...
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32 views

Liquid alternative to alcohol to lower density of water

I am trying to create a suspension of polypropylene particles in a water based liquid. I want the density of the liquid to be more than or equal to the density of polypropylene (855 - 946 kg/m3) so ...
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75 views

How to dissolve PLA/PCL/PMMA?

I have a research about electrospun membrane synthesis where I dissolve PLA pellets in chloroform:methanol (3:1) for 3 hours and also PCL pellets in chloroform:methanol (3:1) for 3 hours too. Another ...
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1answer
103 views

Is it possible to have an allotrope of carbon as a long unbranched chain of itself?

Is it possible to have an allotrope of carbon with formula $\ce{(=C=)_n}$? Well, let's actually leave alone the separate question like from which "monomer" would one produce such a thing (can one ...
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77 views

Calculate the degree of polymerisation. It's molecular weight and its repeat structure are given

I understand how to calculate the degree of polymerisation normally, but in this question, the extra H and OH outside the bracketed monomer have thrown me off. Do I include their atomic masses in the ...
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59 views

what are the cons of converting plastic to fuel

I have been trying to read how to fix plastic problems, there seems to be 3 outstanding solutions Re-use Recycle Decompose to Fuel Recycling is expensive, requires lots of water and the quality ...
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24 views

How to remove the foggy discoloration in polycarbonate tubes caused by acetone?

Unknowing that the tubes used in the centrifuge are made of polycarbonate, I cleaned them with acetone. Following, a white smoky discolouration appeared and the tubes turned opaque. Is there any way ...
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27 views

How can I explain PEO-b-PLA behaviors in dissolution?

I dissolved PEO 10K - PLLA 14K in toluene at the concentration of $\pu{50 mg/ml}$, $\pu{25 mg/ml}$, and $\pu{5 mg/ml}$ including $\pu{30 min}$ of sonication. When I sonicated them at room temperature,...
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67 views

Will acetone dissolve the structure of Spandex?

We are trying to remove rubber from spandex, it's been super-glued on. We know that acetone will dissolve superglue, but we're unsure if acetone will harm Spandex. Anyone that can help us, your input ...
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1answer
32 views

Can common refrigerants be chemically converted into something that is a stable solid at STP? [closed]

I've been thinking how refrigerants - which are highly potent greenhouse gases (hundreds and even thousands of times more potent than CO2) - are likely to be vented to atmosphere eventually either due ...
2
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1answer
122 views

What are glues/adhesives for cardboard boxes/crates made of?

Open cardboard boxes/crates, often for foodstuffs, are often glued to hold their shape. What is the glue/adhesive made of? I ask to know if it is biodegradable, such that it is suitable for ...
6
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2answers
72 views

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 ...
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1answer
41 views

Would the mixture of Latex Rubber and the Squid's chitin make a biodegradable plastic?

I don't know much of Chemistry but I put the chemical structures of each. Thank you!
5
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1answer
59 views

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 ...
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10 views

What is it mean by Grade in thermoplastics?

I have seen some thermoplastics of the same type categorized by its grade .. What does it mean by that? What does it means the word grade in this context? Is it just a name for slightly differences ...
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70 views

Do “random” “2D” polymers constrained to a box actually form “space filling” curves?

Background: The self avoiding walk model is (allegedly) a reasonable model for polymers, at least with respect to certain "universal" (i.e. lattice independent) constants -- see section 1.1. in this ...
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85 views

How good is 2-Butoxyethanol as a replacement for acetone?

I have recently bought a bottle of acetone from my local hardware store. When I opened the bottle, I was surprised about the absence of the strong smell of acetone. Only then I discovered the smaller ...
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1answer
25 views

Catalysts to accelerate foamy polyurethane reaction

This is the reaction that I am referring to: https://www.youtube.com/watch?v=EoRUSo0BWC0 I am interested in finding catalysts to accelerate this fun chemistry demonstration. I have heard that some ...
3
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1answer
75 views

Distribution of polymer lengths

Suppose we have a chemical reaction where a linear chain can form (reversibly) from building blocks (e.g. atoms or molecules): $$\ce{X_$i$ + X_$k$ <=>[$k_\mathrm{fwd}$][$k_\mathrm{rev}$] X_$i$...
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35 views

What determines 3D printing material compatibility?

3D printing, specifically the type common for consumers FDM or FFF, involves laying down thin (typically 0.1 to 0.2mm) layers of molten plastic. Modern consumer printers can use various filaments: PLA,...
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1answer
451 views

What polymer can be dissolved in ethanol and is insoluble in water?

I need a polymer with parameters noted above. How to determine the solubility theoretically? Hansen/Hildebrand solubility parameters? Wypych is not the ultimate solution...
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0answers
38 views

Why are my microgels not centrifuging (sticking to tube)?

I have created a hydrogel water in oil emulsion using a microfluidic flow focusing device. I have been able to collect the microgels/particles from the device and then pipette/manipulate them. When I ...
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0answers
20 views

Will lead bind to dissolved polymer (Kapton) monomers?

We are attempting to determine the concentration of lead impurities in Kapton. Essentially we need to extract lead in the tape polymer Kapton (structure seen below); The amount of lead in the tape is ...
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34 views

What is the difference between radii of Gyration and hydrodynamic radii of a polymer? [closed]

Why do you consider that the relationship between RH and RG should depend on the quality of the solvent?
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110 views

Is it possible to arrest the post-actinic effects of photodegradation in ABS polymers?

Polymers like acrylonitrile butadiene styrene (ABS) are adversely effected by UV exposure, both visually (by yellowing) and with regard to other material properties [1]. What's worse is that the ...
3
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1answer
3k views

Does melting HDPE plastic produce toxic fumes? (melting, not burning)

● The question isn't about burning HDPE but melting it at the proper temperature. (At 120 to 180°C depending on it's density, it becomes gooey. According to the source below the "extrusion" ...
3
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1answer
257 views

What would happen if I combined this polymer and this metal (assuming I can) [closed]

So let me explain, I recently found out about a material called sorbothane (which is a polymer). Now, sorbothane is special because not only does it highly efficiently absorb shock, but also highly ...
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2answers
4k views

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 ...

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