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 ...

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Is it methodically correct to assign negative thermal expansion coefficients to polymers?

Poylmers such as saran wrap shrink when heated. Atomic solids typically have positive thermal expansion coefficients assigned to them. Heated polymers coil up etc., which is a completely different (...
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2answers
16 views

Difference between black and brown eumelanin / red and pink pheomelanin

Wikipedia says the following: There are two types of eumelanin—brown eumelanin and black eumelanin—which chemically differ from each other in their pattern of polymeric bonds. What are those ...
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16 views

What chemical that when cured chemically cross-links to already vulcanized rubber

I'm looking into ways to repair rubber materials and I was wondering if there are any chemicals that when cured will chemically bond to the already vulcanized rubber material. I know this might ...
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1answer
34 views

What are polydisulfide polymers?

What are polydisulfide polymers? How are these polymers applicable in energy sectors such as rechargeable batteries?
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11 views

can PMMA crosslink with vinytrimetoxysilane?

My project is on development of phase change material, which we are using myristic acid as our PCM. We have done the coating on myristic acid with PMMA to avoid acid leaking which may cause corrosion ...
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1answer
46 views

why is laser printer toner magnetic?

I had an old toner cartridge lying around, so I took it apart and emptied the toner into a jar. I had heard that one could make a ferromagnetic fluid using toner powder and oil, so I mixed a little ...
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19 views

A material that could stick to almost anything? [closed]

I am looking for a material that could easily stick to any surface on impact and also detach easily. The Reason: I am making a machine for my first year Mechanical Engg. project that would throw ...
4
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2answers
31 views

Why is nylon formed using carboxylic acids, while aramids are formed with acyl halides?

I was reading about carbon polymers and noticed something interesting about the difference between the reaction used to form nylon and the reaction used to form aramids: in the former, the monomers ...
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27 views

What is the name of the crinkly plastic used in clear parts of envelopes?

I've always wondered what it is, as it makes a lot of noise on being deformed. No other common plastic that I've come across has quite the same properties.
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43 views

Mechanism of polymerization of 4-nitroaniline

Does anyone know the mechanism for/the structure of the product of the explosive polymerization of 4-nitroaniline with concentrated sulfuric acid? My guess is that it is some sort of aromatic ...
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0answers
17 views

Which class of polymerization reactions reaches high conversion under one second?

Are there polymerization reactions that can reach high conversion very fast, say under 1 sec? i.e. to polymerize "immediately"?
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30 views

Gilman Reagent with vinyl chloride

What are the products formed when vinyl chloride reacts with dimethyl copper? I thought the product formed would be propene. But answer given is PolyVinylChloride. How does polymerization take place?
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1answer
38 views

Cross-linking in Latex

My understanding was that cross-linking would generally make a material harder and less flexible, but if latex does have cross-linking, how would this affect its shape and hence its properties, ...
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21 views

Recommended introductory text book about rheology

I'm a student with background in electrical and computer engineering, interested in soft robotics research. Rheology and study of soft solids their related dynamics is just within my plan. Such ...
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34 views

What are the differences between silicone with phenyl and silicone with methyl groups?

I'm doing a work on silicone polymers and my question is what is the difference, in therms of consistency and viscosity, and the chemical differences (properties) between benzenic silicone and ...
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0answers
9 views

Polymer : long limited branching/preferbly straight chained fluorinated acrylate/epoxy

I was wondering if there are any trifluoromethyl acrylate/epoxy with 15 carbon backbone or longer preferably with limited branching preferably straight chained commercially avaliable, preferably with ...
4
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1answer
79 views

Gases produced by pyrolysis of cellulose

I heated cotton in a sealed container (with a small hole) over a natural gas flame. Some gases and smoke were produced. What would they probably be? I can come up with some guesses based on the ...
2
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1answer
197 views

Is the chemical structure of an amide bond (-CONH) or (-CONH2)?

The Dictionary definition of an amide is an organic compound obtained by replacing the −OH group in acids by the −NH 2 group. So from this, I deduced that the bond would be CONH2. But when I ...
2
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68 views

What would be a safe/good surfactant for ultrasonic cleaning vinyl records + distilled water and isopropyl alcohol

Title pretty much says it all besides the type of records I believe are pvc (60s - current, someone correct me if there may be other materials but I absolutely don't have any shellac records) and I ...
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1answer
43 views

Do you say “reduce something to polystyrene”?

this question may not fit in this forum because it's about English, but biochemistry knowledge is required, so please allow me to make this thread. When you measure the molecular weight of a polymer, ...
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1answer
28 views

Percolation network analysis with 1H MAS solid state NMR

Assume you have a composite rubber that was produced in an extrusion process and it consists of a basic polymer with some additives. One of the additives does not get mixed with the basic resin but ...
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0answers
15 views

First usage of PEG (Poly ethylene glycol) on surfaces against biofouling

Is there something like a "famous initial case" when people used Poly Ethylene Glycol (Poly Ethylene Oxide, PEG) as passivating layer or so on surfaces? Especially against nonspecific Protein or ...
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2answers
152 views

What is the difference between Alkanes and Polymers?

As far as I understand, Polymers are long molecules made of smaller monomers which are Alkenes. But polymers don't have double bonds, so they are saturated. What is the difference between Alkanes and ...
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26 views

What are smart polymers and what are their properties? [closed]

Could someone please answer this at the level that is needed in GCSE because that is what I am at right now. Would appreciate it if someone could answer. Thanks.
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24 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 ...
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16 views

Where can I purchase “Poled PVDF Film” from

I would like to know if it is possible to purchase a transparent piezoelectric sheet of PVDF online or at a hardware store, and if yes please state where I can purchase them from. Thanks a lot.
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33 views

What are 1A_g and 1B_u excitons?

I was going through a paper on organic LED chemistry [1]. I saw that the authors referred to "$1A_g$" and "$1B_u$" excitons (and also "$2A_g$" and "$2B_u$" excitons), terms which I don't really ...
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Polymer Science and Technology- Finding osmotic pressure [closed]

Please help me figure out this problem and what is an osmotic head,it doesn't explain what that is in my textbook. I need this problem to help study for my exam.
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2answers
82 views

What is a 'corona phase'?

What is a 'corona phase'? I have come across this term in several papers, including this one but all I have found concerning its definition is: [...] synthetic heteropolymers, once constrained ...
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1answer
137 views

Does the para position on benzene ring-polymers make the structure stronger?

Aramid fibers are strong synthetic fibers. Kevlar is called a para-aramid, and it's outstandingly strong. Why does the para-position give Kevlar its strength? When the Kevlar monomers are in the para-...
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1answer
50 views

Compound with two functional group

Compound X has 3 carbon atoms in one molecule. It contains a primary alcohol and a carboxylic acid functional group. Draw the displayed formula of Compound X. Help! Condensed formula is fine for me!...
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17 views

Inert cyanide groups in polyacrylonitrile(PAN)

Cyanide group undergoes hydrolysis and gets converted to Carboxylic acid. However, the cyanide groups in polyacrylonitrile(PAN) are inert. Why?
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25 views

Solvent for Norland optical adhesive

I'd like to know if there is any solvent that dissolves Norland Optical Adhesive 65 (and Rhodamine 6G) but not PMMA that is used in e-beam lithography. (I've tried Acetone,Methanol,Chloroform, n-...
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1answer
113 views

Are we wrong about Bakelite formation mechanism?

In the reaction of phenol with acetyl chloride the oxygen of the phenol attacks the acetyl chloride. In Bakelite formation we know that pi electrons attack the carbonyl carbon of formaldehyde.My ...
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1answer
63 views

Organic chemistry polymerisation

I have a doubt regarding the polymerisation of ethene, in the case of polymerisation, we basically are arranging the molecules in a systematic order and thus decreasing its entropy so shouldn't we be ...
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31 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 ...
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15 views

How can I restore the surface of ABS polymer products?

Recently I asked a question about de-yellowing Lego. I have a follow-up question on this. I try to design a setup where I can de-yellow Lego and remove/obscure any scratches from the surface of Lego ...
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0answers
82 views

Why do polymers have higher coefficients of linear thermal expansion than metals?

What started out as a homework question is now bothering my brain. I have always known that metals expand pretty well when their temperatures increase. Also, I have never heard of polymers like Teflon ...
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0answers
77 views

Synthesis of Polyvinylidene fluoride (PVDF)

I would like to know what the easiest way of synthesising PVDF is, or is it easier to buy the polymer online, and could PVDF be made transparent. Thanks
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1answer
21 views

Hair Gel Derivative

I need a water-soluble, extremely fast drying adhesive gel. My first thought is hair gel. pros: Water Soluble (easily removed)*** most important High viscosity in liquid form ~60 cps Easily ...
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22 views

What polymer can plug the leak internally?

Like they said in the web site http://www.pipefuze.com/how-pipefuze-works/, I wonder what kind of polymers can do the works in part A and B? Part A – Polymer & Filler – The polymer and filler is ...
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28 views

Speed up polymerisation of formaldehyde

Is there a way to speed up the formation of para-formaldehyde in a formalin solution?
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48 views

Investigating the displacement of a Se anion by a Sulphide anion

I am working with CdSe Quantum Dots suspended in hexane. I then tested the photoluminescence of my solution. Then I mixed my CdSe dots with a mixture of an organic conducting polymer which was ...
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1answer
51 views

How do I determine which liquids are immiscible with one another?

I am trying to work out which type of ferrofluid I can use to form a weak magnetic seal for a container of liquid photopolymer resin. Is there a mathematical approach to determine what substances will ...
4
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1answer
104 views

Why plastic sheets contract when heated?

Why do thin plastic sheets contract when heated, contradictory to the behavior of most other materials ? What are the things going on at the molecular level ?
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24 views

Estimate inflammability of ABS?

I am studying some electrical components and particularly Raspberry Pi 2 official cases. Their manufacturer says that they consists of ABS (Acrylonitrile butadiene styrene) when I ask if their ...
3
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60 views

What are the dangers of melting HDPE and silicone? Is it even possible?

I've searched the internet and couldn't find a specific answer. There doesn't seem to be a single recycling company that takes empty silicone tubes (also know as mastic tubes) and recycles them. As a ...
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0answers
69 views

Curing of polyester resin that did not reach top exothermic temperature

When working with polyester resins for fiberglass or geloat, there are times where the thickness of the resin on the substrate is not sufficient to get a strong exothermic reaction and achieving a ...
4
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1answer
109 views

Do polycarbonate and/or polyurethane have latex?

I have a severe latex allergy which hinders my health every day via hives, inflammation, and breathing trouble. I am trying to find a cell phone that is not going to cause anaphylaxis or other ...
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1answer
137 views

Is there an easy way to make PVC from PVA?

Say, I took Elmer's glue (or a similar Polyvinyl Acetate) and I inserted some Chlorine Tabs and warm it up while stirring. Would the electronegative Chlorine turn some of it it into Polyvinyl ...