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Questions tagged [polymers]

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

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4 votes
2 answers
340 views

How can I prevent my spin-coated silica thin film from cracking when I heat it up?

I am spin-coating a porous silica solution on a glass microscope coverslip, and then heating the resulting thin film to $\pu{350 °C}$, in an attempt to create a thin film of porous silica sol gel. I ...
4 votes
1 answer
117 views

What role does CaCl2 play in a gelation medium?

To produce sodium alginate beads coated with chitosan, following procedure was undertaken: Sodium alginate was dissolved in distilled water at a concentration of 4% (...) The gelation medium was ...
3 votes
0 answers
34 views

Is the "heat or UV" necessary for PVC10 + Cl => CPVC10 catalytic or endothermic and if endothermic how much energy?

Production of Chlorinated PolyVinyl Chloride (CPVC) from PVC and chlorine requires incorporating about one part chlorine in 10 PCV to achieve around 63% chlorine mass CPVC. This reaction is "...
0 votes
0 answers
34 views

drying polymers / FDM 3D printer filaments

My understanding is PLA can absorb 1%, and some others (ABS?) can absorb up to 10% moisture. In order to dry a polymer, is additional (more than room temperature) heat needed (like a filament dryer/...
10 votes
5 answers
2k views

What is an effective fabric-friendly solvent for aluminium chlorohydrate?

I have recently found out that the white/yellowish "sweat" stains one occasionally finds on t-shirts might be aluminium chlorohydrate polymers. While talk about aluminium and antiperspirants is all ...
0 votes
0 answers
67 views

Biodegradability of Polymers

Nylon-6 is a polymer of 5-amino caproic acid (although it is generally prepared by hydrolysis of caprolactam) and Nylon-2-Nylon-6 is a copolymer of glycine and 5-amino caproic acid. While Nylon-2-...
5 votes
0 answers
112 views

UV curable adhesive

I'm looking for a UV curable adhesive that can be removed without peeling or burning. Ideal removal would be some kind of solvent over a relatively short period of time. I also need it to have a ...
3 votes
1 answer
398 views

At what temperature do complex hydrocarbons become ashes?

When heating a metal tube with polypropelene in it, i found that i still had brittle black foam and flakes in it even though it had been in a blue flame at around 500'C What happens to complex ...
4 votes
2 answers
142 views

Could polydiazene exist?

I am a bit new to the world of chemistry, and after messing around on ChemSpider, I had a thought. Could a polymer like this exist: Due to VSEPR, it would be shaped pretty weirdly and N-N single ...
0 votes
0 answers
30 views

Synthesis of polypropylene

So, I have two questions regarding the synthesis of polypropylene: I have tried looking everywhere but couldn't find a detailed mechanism for the termination step of the synthesis of polypropylene (...
8 votes
1 answer
1k views

What is 'spray foam' or 'expanding foam'?

At the wikipedia are: Spray foam (expanding foam in the UK) is a chemical product created by two materials, isocyanate and polyol resin, which react when mixed with each other and expand up to 30-60 ...
0 votes
0 answers
20 views

Difference between polyethylene sulfonate and Nafion?

Nafion is a cation-exchange membrane that I would like to build a chlor-alkali cell, but unfortunately it's crazy expensive(and comes in ridiculously large sizes). Its functional group, the sulfonate ...
0 votes
0 answers
23 views

Replacing calcium acetate with sodium polyacrylate for homemade Sterno?

I was researching making canned heat using denatured(ethyl) alcohol, water, and calcium acetate from scratch. However, it occured to me that sodium polyacrylate also absorbs water and alcohol and is ...
0 votes
0 answers
46 views

Is there a name for polymer structures that resemble a foldable lattice?

I'm struggling to find the right descriptors for this, but it would look like this I've been doing some layperson reading up on stretchy materials, and I know a lot of them work by the polymer chains ...
2 votes
4 answers
9k 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 ...
2 votes
0 answers
33 views

Small-Angle X-Ray Scattering of Bulk Polymers

Does anyone have any recommendations on how to get useful information from SAXS of polymers when the system is not dilute? This is the type of data we're working with: My understanding is that since ...
3 votes
0 answers
104 views

Chemical Mechanism Behind Water-Soluble Ink

I came across water-soluble ink pens designed for creating temporary fabric marks, particularly in cross-stitch stamping. These ink dissolve in water, transforming water into a colorful liquid, while ...
1 vote
1 answer
705 views

Assignment of NMR peaks of polystyrene

I’m having trouble identifying the peak around 3,75 ppm in the 1H-NMR spectrum of polystyrene measured at 400 Hz in CDCl3. Could someone please provide their perspective on it? I see it appear in a ...
1 vote
0 answers
30 views

Does polyamide react with hydrocarbons (group III engine oil) in its thermoplastic state?

I need to form (bend) thermoplastic polyamide hose in rubber jacket to a desired shape. I can use heat gun but I thought for better results I could use heated to 150C group III engine oil (your ...
1 vote
1 answer
231 views

liquid (solution or polymer) with a density of more than 1.35g/cm3 and with element atomic numbers less than 9

Search for a liquid (solution or polymer) with a density of more than $\pu{1.35 g/cm3}$ and containing only elements with an atomic number less than 9. For example, a saturated solution of sugar in ...
5 votes
0 answers
63 views

Dependence of elasticity on temperature and degree of vulcanization of typical commercial rubber band

I am doing a school experiment that tries to find how the elasticity of rubber band depends on temperature. From all the research I have done, theory suggests stress to increase linearly with ...
3 votes
0 answers
29 views

Can multispectral imaging be used for identification of materials, substituting for hyperspectral imaging?

Nowadays a lot of research and applications are using Hyperspectral Imaging for identification and segregation of plastics by material. But the cost of a HSI system is quite high. Could a ...
0 votes
0 answers
37 views

How to remove color from bromostyrene/dibromostyrene

Distillation under low heat can remove color (excess bromine) but this is time consuming and there is a danger of bromostyrene polymerization even with added TBC. In aqueous, sodium thiosulphate can ...
0 votes
1 answer
49 views

Can plastic items of same type but different rigidity be recycled together?

Quite often we find plastic items of different rigidity which belong to same type. For instance, LDPE is used mostly for films and bags, but sometimes thick and rigid containers are also made. Can we (...
2 votes
1 answer
63 views

Does Sugru (Formerol) decay underwater?

Sugru is described as waterproof and dishwasher-safe, but I still wonder if it will decay quickly (within months) if submerged in room-temperature tap water. Aren't silicone rubbers susceptible to ...
0 votes
0 answers
30 views

Which is more stable, a secondary allylic carbanion or a primary allylic carbanion?

I came across this picture in a polymer chemistry course, specifically on anionic polymerization of conjugated dienes (butadiene). I dont understand why the secondary carbanion is more stable. Based ...
2 votes
1 answer
529 views

What are the bubbles and crystals found in sodium acetate hot packs after use and storage in the solid form?

When sodium acetate trihydrate hot packs are regenerated soon after activation, they regenerate to a clear liquid upon boiling (typically with an air bubble that was not present in the new pack) On ...
4 votes
3 answers
913 views

Why don't proteins form branched polymers?

My reference book (Princeton Review for SAT Chemistry Subject Test) mentions that: Proteins and carbohydrates are both polymers; however, only carbohydrates commonly form branched polymers. Glycogen ...
1 vote
0 answers
19 views

Thermoplastics crystallization during nonisothermal cooling cycles

I have tested a PAEK family polymer using differential scanning calorimetry (DSC) with heating-cooling-heating cycles under different cooling rates (heating rates remained unchanged). PAEK are semi-...
1 vote
0 answers
45 views

Can polychloroprene further react

Chloroprene undergoes radical polymerisation to form polychloroprene. Chloroprene is a special structure since it has two carbon-carbon double bonds and it turns out that polychloroprene also has one ...
0 votes
1 answer
50 views

cellophane bags

I am conducting an experiment to test the components of a cello bag. I believe that cello bags do not just contain cellulose, and as mentioned by many websites, only 92-98%, but not 100% of the bag is ...
6 votes
1 answer
2k views

Why does plastic tear easier when you pull it quickly?

If you've ever taken the plastic from a plastic bag and pulled on it, you might know what I mean. If you pull quickly, the plastic tears relatively easily, but if you pull it slowly, it gets stretched ...
2 votes
2 answers
3k views

What's the difference between FFKM and PTFE?

These two fluorocarbon polymers seem to me very similar, the only difference I see is that FFKM is elastomer while PTFE aka Teflon is more of hard type of plastic. Isn't FFKM just PTFE with lower ...
10 votes
3 answers
1k views

Research-backed articles on cast iron seasoning

I've always seasoned my cast iron pans with vegetable oil because that was what I was taught. I'd done some research before, and even came across this StackExchange post on asking the best oil for the ...
0 votes
0 answers
196 views

Why does ethanol decrease viscosity of a high pH carbomer solution more compared to water

Carbomer 407 is made up of acrylic acid that undergoes polymerisation to form a long linear structure. At higher pH, the carboxylic acid functional groups will dissociate to form carboxylate ions. ...
2 votes
0 answers
174 views

How to dissolve paraformaldehyde in solvent without using water?

In the chloromethylation reaction of polysulfone (PSU), I am required to use paraformaldehyde and trimethylchlorosilane as the chloromethylating agent while stannic chloride as the catalyst. I ...
1 vote
1 answer
49 views

Adding colours to polymers

It is said that some polymers can be dyed, but I am not sure about the mechanism behind. Let me take an example. In anodization, aluminium oxide can be coloured since there are tiny pores for the ink ...
0 votes
1 answer
90 views

What resin is appropriate for construction of a gasoline/ethanol fuel tank

I am building a epoxy resin/glass reinforced plastic (epoxy/GRP) gasoline tank. The expected service life is 30 years. I've read that epoxy is relatively resistant to gasoline (some better than others)...
-1 votes
1 answer
71 views

What is that substance coming from tractor tire?

I have old tractor with Bridgestone tires. When I press a clean white tissue against the tire, a black spot show on the tissue. Is that substance carbon black and it’s harmful to soil?
1 vote
0 answers
27 views

What is the diffusivity of colloidal Formazine in water?

I have synthesized Foramzine in an aqueous solution (turbidity = 4000 NTU), and will be further diluting it. I would like to know the diffusion coefficient (diffusivity/mass diffusivity) of colloidal ...
4 votes
0 answers
449 views

Does (BeCl2)n have 3-center-4-electron-bonding or not?

The title really explains what the issue is here. I would think that it has multicenter bonding akin to $\ce{(BeH2)_n}$ polymer, because they are pretty much iso-structural (although it shouldn't have ...
5 votes
1 answer
9k views

Is teflon a poison if ingested? [closed]

Nowadays, a lot of frying pans are made with a non-stick coating. That's usually teflon, or chemically speaking polytetrafluorethylene - $\ce{(C2F4)}_n$. Can you be poisoned if some of that teflon ...
2 votes
0 answers
45 views

Why is sodium p-toluenesulfonate used as a supporting electrolyte in polypyrrole synthesis?

First, some preamble: I'm currently working on my thesis, which is about the electropolymerization of polypyrrole onto carbon fiber felt. My methodology, for the most part, follows a paper by one of ...
1 vote
0 answers
32 views

Can an epoxy resin create a terpene polymer?

I am developing plant-based antifouling coatings that will stop barnacles binding to ship hulls for example. I have started simply by mixing specific terpenes with an epoxy resin (BISPHENOL A ...
2 votes
0 answers
70 views

A durable rubber type material that can flex easily but return to its original shape very fast

I'm looking for a durable rubber type of material for a guitar pick holder. The material I'm looking for will need to have flexibility to pick individual notes of a guitar, but needs to return to its ...
-3 votes
1 answer
81 views

Acetone resistant elastomer

I am in search of an elastomer that can be dissolved in solution and applied and cured at room temperature, but that has good chemical stability to acetone once cured. Does any such elastomer exist?
3 votes
0 answers
43 views

How do polyurethane varnishes cure after only the solvent evaporates

How do polyurethane varnishes cure after only the solvent evaporates? I believe that polyurethane varnishes have as components isocyanates & polyols that react to form the polyurethane portion of ...
3 votes
1 answer
194 views

How can I compare the UV/Vis absorption difference after metal ion chelating of crown ether-containing polymer?

Recently I have synthesized the polymer that contains 1-aza-18-crown-6 in the repeating unit. I want to know if there is any UV/Vis absorption difference after the chelation of metal ion. Considered ...
0 votes
1 answer
55 views

Effect of changing of the concentration of reactants when concentration of the initiator and the concentration of the initial reactant are very small

A + I---> p What happens to the rate of the reaction when the concentration of the reactant is changed in a system that its concentration of its initiator and the concentration of the initial ...
2 votes
1 answer
44 views

Humidity diffusion in Silicone Elastomer and effects on refraction / transmissivity

There is an issue I'm facing that is very tricky. A solar cell that is encapsulated in Sylgard 184 Silicone Elastomer with a front borofloat front glass. This cell is used to measure a light intensity....

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