Questions related to Polymer Synthesis
I am new to polymer field and willing to prepare polymer (conducting) during synthesis (calculation) with pyrrole and some oxidization reagent we have to choose 1:2 ratio. I am not getting why we are choosing 1:2 ratio any one plz suggest me any information regarding this or else any book regarding these calculation of polymer synthesis.
I am doing polymer synthesis, but the amount of polymer I can get from one synthesis is very small, about tens of microgram. I am using GPC to characterize it, but the information I can get is very limited.
Could anyone suggest any characterization method to get the polymer structural information that only use very small amount of samples? Better recyclable.
Thank you very much!
Our group is trying to synthesize PIM-1 and bought some TFTPN from different companies. However, the TFTPN from different companies showed different colors-from white to yellow. The companies told us that they are the same good and provided us with the NMR spectrum. I am confused about how could the same compound has two colors. Did you encounter the same issue before or have any idea?
I am currently attempting to synthesize Methacrylate-headed PEO macromonomer using Methacryloyl Chloride (MAC) and PEO in Toluene containing Pyridine. I am unsure of the ratios needed for the synthesis. After evaluating some of the structures and possible by-products I was going to start with [2:1] ratio of MAC and PEO, [1:1] of MAC and Toluene, and [3:1] Pyridine and Toluene. If anyone with polymer synthesis experience could shed some light on figuring out the ratios better or if this sounds like a good place to start would be great. Thanks!
What are the best books in chemistry that can be used for curriculum design "i.e. for Materials Chemistry"?
Please write the name of the best books that you read/know in the field of "chemistry"? General Chemistry, Organic, Physical Chemistry, Inorganic, Biochemistry, Polymer synthesis, Polymer Chemistry, Computational Chemistry, Solvents and Solvation theories, Analytical Chemistry, Electrochemistry, etc [...] and Chemistry Laboratory Design.
Thank you very much
- - -
* Additional comment:
You can, also, send to me links (or the books' front page photo) or E books (PDF or any) here or in private message. Thank you!
I did some reaction of polymer synthesis in which triethylamine was used. I have NMR of the resultant polymer in which I am expecting that triethylamine is converted into diethylamine. Is it possible? Please share some references. Thanks in advance.
I am a synthetic polymer chemist. I would like to explore the simulation counterpart of my experimental work. Can anyone suggest a good software able to simulate polymerization reactions, and possibly some properties of the obtained polymer?
Please, notice that I am not looking for a chemical engineering simulation software.
I am currently running thermal polymerizations of compounds that form free radicals at elevated temperatures (T>120 degrees C). I want to attempt to polymerize at discrete temperatures between 120 and 200 degrees C.
Can I use AIBN radical initiator at these elevated temperatures without risk of explosion (in the literature it seems that AIBN is typically used at temps ranging from 60-80 degrees C)?
If not, is there another radical initiator I can use at temperatures this high??
My thesis is defined base on acrylated Polyurethan. I used HEMA (hydroxy ethylmethacrylate) as a reactive diluent and benzophenone (BP) as a UV initiator with methyl diethanolamine as an accelator. But my system is so viscous and needs heating for adding photo initiator and proper mixing. I use 45º c for adding photo initiator and mixing. but most of the time it stat to crosslinking from the bottom of the sample container. I mean before curing with UV lamp it start crosslinking.
I thought that its because of BP . Its a thermal initiator too. so I need a UV initiator can be used in higher temperature. Could you please introduce appropriate one?
I am currently looking for PhD candidates or PostDocs with a strong background in monomer and polymer synthesis for my lab at the University of Freiburg, Germany. If you know of any suitable candidates, could you please direct their attention to my lab? Thank you!
I used EBiB as an initiator to polymerize acrylic monomer. However there are always some dead chains shown in GPC and the PDI is 1.3~1.4. Does this mean my initiator is too active for this monomer and the radical may not go back to dormant species before they terminate? Should I use less active initiators like MBrP? Or is there any other variables I need to adjust like the amount of AIBN or Sn(EH)2? Thank you!
I have to end a reaction in process due to sone emergency. I was synthesizing poly glycerol sebacate. I reacted them at 170 under nitrogen for an hr and then stopped. Normal duration is 4 hr. Should I continue it from ther or to go for new??
According to the fact that we couldn't use huge sonicators and run the same lab based experiment for industrial productions because of its acute or chronic health effects, I wonder what is the best replacement for sonication to obtain a homogenous mixture of polymers and nanosheets in industries?
I am doing polymer synthesis research. The project is to synthesize poly-l-lactic acid with polypropylene glycol to get a triblock copolymer. Stannous octoate is the catalyst, solvent is toluene and reaction temperature is 140C, reaction is carried out under nitrogen atmosphere. After reaction is done, toluene will be evaporated by using rotary evaporation, product will be dissolved in dichloromethane and titrated to cold methanol or diethyl-ether. The major problem is the products will be dissolved into methanol or diethyl-ether and I can't successfully collect them. Even the hilderbrand solubility parameter of methanol and diethyl-ether are much larger than polypropylene glycol 's.
I have two main considerations:
1. There are not lots of initiators to initiate the polymerization, maybe I will add some general initiators like AIBN?
2. I successfully synthesized the product, I need to select a correct solvent instead of methanol or diethyl-ether.
Can someone give me some suggestions?
we specialize in styrene-butadiene emulsion polymerization, we run conversion to 60%, and we recover the unconverted (1.3 butadiene) at a purity of average of 73% and major impurity is (cis-2 butene), how can we minimize this impurity formation
I'm working in a Polymer synthesis And i need a GPC instrument to characterize it and i cant find it Anywhere in Egypt cairo i need help
I'm trying to react a bis-aminopropyl linear PDMS oligomer with a short PEG acrylate via a Michaels addition to form a triblock copolymer. My read of the literature suggests that this reaction should proceed easily via heating and should not require a solvent but this has been unsuccessful so far. I have tried the reaction both neat and in ethanol, with and without a weak base catalyst (triethylamine) and with and without heating.
Can anyone hazard what I might be doing wrong here? NMRs appear to show some conversion is occurring, but some of these reactions have been left on for a weak or more without achieving quantitative yields of product.
Any thoughts would be greatly appreciated, thanks
Not really getting much luck in researching this on my own, and I'm also new to the area of latex polymerization so maybe I'm missing something. I'm trying to calculate the interaction parameter of a polymer that I'm synthesizing, but I don't know what the structure actually is since its I'm just using free-radical polymerization to get a polymer from 3 different monomers of changing concentrations. If anyone has any leads or ideas to do this, it would be appreciated. Thanks in advance!
I am synthesizing a material based on a cyclosiloxane compound, where I am attaching functional groups onto the silicon atoms. My worry is that the siloxane ring could open during the reaction, as they are notoriously weak rings, which is something I do not want to happen. The silicon atoms have 5 carbon arms, and I am attaching a compound at the end of each arm. Therefore, it is impossible to tell whether or not the ring has opened by conventional methods (H & C NMR, FTIR, MS...etc.). The only method I can think of is using Si NMR, would that prove whether or not the siloxane ring has opened?
I am struggling to purify a series of polyesters which do not have melting points. That is to say, they do not nicely precipitate in non-solvents and instead form highly viscous gels. I have allowed these gels to form in non-solvent while in freezer, and then have successfully decanted the mixture, leaving a crude gel behind. However HNMR still reveals the presence of unreacted monomer. There are not any literature boiling points on my monomers in this series, but they must be quite high (mw = 400-600). [I have tried vacuum drying at 100 millitorr @ 80C with no luck].
Any suggestions? Thanks!
I want to synthesize PEDOT and de dope this polymer
I will conduct the experiment like below method.
I have a question. which hydrazine can I use?
Hydrazine anhydrous? or Hydrazine monohydrate?
The monomer is easily polymerized due to its low oxidation potential. The polymerization procedure is depicted as follows: 0.591 g EDOT and 2.08 g FeCl3 were mixed under nitrogen with 20 ml freshly distilled CHCl3 in a 50 ml three-necked flask with magnetic stirring. The reaction lasted for 48 h at room temperature. After filtration of CHCl3, the black compound was washed with dilute hydrochloric acid, distilled water, and then was extracted by ethanol in a Soxhlet extractor, dried at 80 ◦C in an oven to constant weight (0.581 g, yield 98.3%). The polymer was stirred in hydrazine for 5 h to de-dope, then was filtered. The black solid was extracted in Soxhlet extractor one more time with ethanol. After drying to constant weight, 0.577 g black powder was obtained
In the first step i am synthesizing hydroxy polyethylene glycol acrylate - 200 (HPEGA - 200). The above step is immediately followed by the addition of acrylic acid, sodium salt of 2-methyl-2-propene-1-sulfonic acid along with sodium persulfate as an initiator. During the second step immediate frothing and rise of the products inside the flask was observed. Frothing and rising even goes beyond the attached refluxing unit of 300 mm length. This results in spilling of the products outside the system which interrupts the reaction and i couldn't get the final product.
I don't understand what is the problem during my synthesis
Could anyone please help me out.
Most of the literature suggest that primary diols have high potential for the chemical industries. What would be the strength and applicability of polymer obtained from diol containing one primary and a secondary alcoholic group?
I'm synthesizing a PLLA grafted with itaconic anhydride in a rheocord mixer. After the grafting, I would like to determine the concentration of the grafted itaconic anhydride.
I dissolved a grafted PLLA sample in THF and then I carried out an acid–base titration with 0.005 M potassium hydroxide (KOH) in ethanol.
I tried to determine the equivalent point in two different ways at 25°C:
1) by means of phenolphtalein as indicator;
2) by means of a pH-meter (CRISON TitroMatic 1S equipped with an electrode CRISON 52.2) measuring the pH and the conductivity.
In both cases I had problems:
1) I can't appreciate the color changing of the indicator;
2) the system seems to be unstable and both the pH and the conductivity fluctuate.
I guess the problem is related with the solvent (THF) because when I tried to perform a similar titration in a water/ethanol solution the pH-meter gave stable results.
My questions are:
Is there any alternative method to determine the anhydride concentration?
Or is there any solution to let my system be more stable to perform a pH measure?
I am working on star shape polymer synthesis by ATRP reaction
I used erythritol core activated with 2-bromoisobutyryl bromide. I used HPMA with MMA in different ratio, anisole, CuBr, PMDETA, Nitrogen gas to deoxygenate reaction flask, Temp-90 degree C.
I am getting green sticky material even after I tried to remove Cu by alumina column, when I tried purification by precipitating in diethyl ether, it is not precipitating.
Why this is happening?
Can anybody please suggest me the better way to get my product?
I am aware that the standard way to remove MEHQ from Methacrylic Acid is to perform reduced pressure distillation. The papers I see suggest using ~ 10 Torr pressure to perform distillation. Unfortunately I do not have access to such a pump. I am very aware of the fact that I can just add a little extra initiator, I was wondering if there was a way of removing MEHQ apart from the reduced pressure technique.
I want read and understand the complete mechanism of Thermosensitive Hydrogel Synthesis, as well as wanna Major catalysts and the structural and mechanical Role in thermosentive polymer synthesis.
I am trying to make PLGA-PEG nanoparticles. For this, first I make PLGA-NHS from PLGA-COOH bu using PLGA-COOH , NHS and EDC in DCM.
I precipitate it (PLGA-NHS) using Methanol.
Further, I use this PLGA-NHS with PEG-COOH + DIEA in Chloroform.
The reaction is kept on stirring for 24hr. But when I precipitate it, i don't get a proper yield. The maximum I could get is 3% yield, which is unacceptable.
Can anyone tell me which can be the problems, or critical steps .
I intend to prepare a solution using melamine-formaldehyde powder. Is there any solvent which can highly dissolve it?
I am using EIS to investigate the anticorrosion performance of polymeric based nanocomposite. Recently I have got a comment from one reviewer regarding my Nyquist plots that it must be isotropic.
What does that mean and how to achieve it??
Samples of my Nyquist plots are attached
Hello Everyone ,
I am going to work on polymer nano composites, kindly suggest me and share me the synthesis of nano composites and preventing the agglomeration of nano composites. How to bind with the polymer,
synthesis method with an Eco-friendly approach. Wish to know the basics. It will be very helpful if some one suggests articles and books related to this .Thank you very much.
I have done the reaction at 0 degree. The substituted group affected the polymer yield. Is it possible to increase the yield of the substituted polymer group by oxidative polymerization method?
Hi everyone, I have a doubt. Polymer synthesis is new for me. Usually, polycondensation reaction of polymers (synthesis of poly arylene ether) takes place using DMAc as the solvent and 170 degree celcius. Some polycondensation reaction (involving aminated monomer) takes place using NMP as the solvent and the temperature around 150 degree. Please explain why NMP as a solvent and low temperature. Thank you very much for your consideration.
I am thinking that does the molecular weight of polyol affecting the drying time of polyurethane dispersion coating?
and if there is no longer excess isocyanate content in the dispersion thus, no moisture-curing with oxygen in air, will it still dry?
My samples (using copolymer polyol) seemed to be tacky and could not dried.
I am thinking does the type of polyol affecting too? I am using normal polyol and copolymer polyols. The copolymer polyols dispersion cannot dried well despite increasing NCO/OH ratio.
Thanks in advance.
I'm trying to make a film using Polycaprolactone(PCL) by solution casting method
at first, I used PCL (Mw ; 70000) but it crystallized too fast and became really hard film when i dissolved PCL in the condition of 10% w/v (10g of PCL/ 100ml of Chloroform)
So i bought PCL-diol (Mw : 2000). It was solid and waxy.
I dissolved it in solvent and dried for 24hr. but it didn't became film.
does PCL-diol have a film making property?
I know this is a long shot but I am trying to microencapsulate a PCM containing a mixture of an alcohol and fatty acid ester and have currently only found in-situ polymerisation using the following surfactants: styrene maleic anhydride copolymer or sodium styrene maleic acid colpolymer as potential ways of doing this (the alcohol group makes microencapsulation a lot more difficult). If anyone has any other possible suggestions of surfactants or microencapsulation methods let me know!
free radical polymerization using PEG-ABCPA as macroinitiator
When I was injected Vinyl acetate monomer in emulsion polymerization reaction then reaction temperature decreases immediately my actual question is that I want to increase temperature up to 80*C so what will do for it
I want to know the catalyst and solvent to polymerise aromatic diol and aliphatic dichloro. Earlier I tried, but not achieved good molecular weight and also polydispersity index is 2.5.
Also please send URL of a particular article also.
One part of my PhD thesis is synthesis of biodegradable polyurethane based on hydroxylated Polylactic Acid. In this case synthesis of hydroxyl terminated PLA is required. I used polycondensation process with lactic acid (LA 90%) as monomer and DBTDL as catalyst an butanediol (BD) as a diol function. the period of process was set at 8 hour on the 180 °C with nitrogen purge and under vacuum . With 1 mole% BD (1 mole percent of LA) the acid number of 84 and hydroxyl numebr of 96 were resulted (by Titrasion method of end groups) , and with 4% of BD the acid number of 15 and hydroxyl numebr of 138 were resulted , also the molecular weight of latter on was lower . But in the articles the acid number of hydroxylated PLA is reported mostly below 2.
So what do think about my test results? Are they reasonable data? do you have any advice for me? I mean higher acid number is reasonable for molecular weight near 3000 of PLA-OH ? what wrong about my procedure?
Also another question is that does such kind of condensation process need condenser set up or just nitrogen purge and vacuum is enough ?
I need PLA-OH weight with molecular approximately 4000 and OH number near 40.
Thank you all for your time .
My question concerns the use of isopropanol for the synthesis of carboxymethylpullulan or dextran. I know that it can improve the obtained substitution degree and also protect the polysaccharide from hydrolysis due to the NaOH. But anyone knows why? Thanks in advance
To prepare a homopolymer by emulsion reaction, what is an efficient way to control the molecular weight and polydispersity? monomer/initiator ratio, chain transfer agent, reaction time?
Could anyone suggest a polymer having following properties?
1. It should be easily soluble in water at 20 degree C
2. It should NOT be soluble in ethanol
3. It's melting point must be well above 100 degree C
4. It should NOT have any hydroxy, carboxylic, and amine functional groups in the side chain.
What is the difference of real system and equation by Flory?
For example, polycarbonate condensation polymerization, PDI is usually 2.2~2.4 by GPC.
This is a step-growth polymerization not a chain-transfer or radical polymerization.
BPA + DPC = polycarbonate + phenol
Thank you for answers! You give me many hints!
I would like to synthesis materials through soft chemistry method. When I am reading the steps it is mentioned about polymerization process to obtained xerogel. Please kindly anyone could explain about it. Thank you.
Follow the link https://www.researchgate.net/post/Is_PCL_dissolvable_in_Ethanol#5913ca134048544dd471fe4c
I see some researcher mentioned this topic and gave some articles for this.
Mushtaq Ahmad · 127.01 · Pakistan Atomic Energy Commission
howerver, this paper cited information about PCL solubility form other papers
Coulembier O, Degee P, Hedrick JL, Dubois P. From controlled ring-opening polymerization to biodegradable aliphatic polyester: Especially poly(beta-malic acid) derivatives. Progress in Polymer Science. 2006;31:723-47.
I cannot find information from this. I am really confused about this information. Can u help me give more papers five exactly information bout PCL solubility
To synthesize polyurethane prepolymer using TDI it is necessary to remove unreacted excess monomeric TDI to reach low free monomer prepolymer. What is the most simple way and which procedure is industrial?
I have been using the ones reported by Grubbs and coworkers but my polymeric nano-particles' Mn ever matches their predicted Mn. The procedure calls for adding a solution of the catalyst (Grubbs III) to a solution of the monomer and stirring at room temperature then quenching with ethyl vinyl ether after which the product is collected by precipitation in hexane:ether (1:1). I tried varying the time and/or he concentration of the monomer solution as well as the sequence of addition of reagents but nothing seems to get the polymerization to produce architectures with a measured Mn that is close to the predicted Mn. The GPC machine is calibrated against polystyrene standards and my polymeric nano particles are made of polyethylene glycol. I don't know if calibrating the GPC against polyethylene glycol standards would help but I am going to do that assuming that the way nanoparticles fold in solution is a contributing factor.
Dear fellow researchers,
I am currently performing a polymerization process and wish to know the overall percentage conversion in regards to my initial monomer content.
I have seen in some articles the use of H-NMR to investigate the conversion. However, my sample is in aqueous solution, will the presence of water affect the readings obtained through the H-NMR? In case it does affect, should I dry my sample prior to testing? In the event I do so, the effect of drying may have a chance to evaporate my monomer as it is volatile.
Else, do any of you of another possible method to calculate the conversion.
Thank you all for your attention
I was using Paraformaldehyde in some of my reactions and its Molecular weight was unknown.
For measuring viscosity average molecular weight different concentrations of paraformaldhyde solution is required. But, paraformaldehyde is insoluble in water at room temperature and dissolves in water at 60 C and we get clear solution after addition of NaOH.
if paraformaldehyde dissolves in water it forms formaldehyde solution instead of paraformaldehyde!!
can any one suggest,
1. How to prepare different concentrations of Paraformaldehyde solution (or) 2. Mark-Houwink constants for paraformaldehyde solution in water
What is the appropriate concentration for the diol and isocyanate if want to get hight molecular polymer? And DMF, DMSO, NMP, which one is the good solvent for this polymerization? How long will this reaction take and generally whether it should be heat up if DBTDL catalyst has been added? And if I do 0.1mmol scale polymerization reaction, which require only very limited amount like 5uL catalyst, whether adding 1 drop of DBTDL directly will affect the polymerization?
I have been using formulations from the 1920's and 30's from the patent literature to create the resole prepolymer. There were a couple of cases that addressed this colour issue. One that I found on my own was the use of a nitrogen purge throughout the prepolymer synthesis, which helped a lot. It still gets slightly yellow and darkens upon curing. Other methods have involved the use of neutralizing acid for the sodium hydroxide catalyst; lactic acid was used but this did not give clear resins. Other concoctions have been suggested to bleach the resin with no help.
I am synthesizing cross-linked and pyrolysised PVDF membrane via the procedures followed by Science 353(6301) 804-807, 2016. I am worrying about byproduct gases during the pyrolysis of PVDF membrane. Fluorous gases might be formed and it would affect the furnace and medical problem. I would like to know and respond this issue safely. Plus, the followed paper used stainless-steel mesh was loaded into the tube, I think that it caused protect the quartz wall of the tube furnace against the byproduct gases. Is it worling well? If it is not, anyone has alternative?
Our group aims to use the reduced molecular weight polyester in a reactive copolymerization with another to produce a compatibilizer for blends using this two polymers. What are the most efficient way to make this molecular weight reduction?
I want to synthesize polyaniline from anilne. I have read that aniline needs to be distilled before being used in the polymerization process. How do I get distilled aniline from aniline
I search an accurate method for determiantion hydroxyl value in Hydroxy acrylic resin, saturated polyester resin and alkyd resin.
I read some articles about how to synthesise solvent-free acrylic hot melt pressure-sensitive adhesive with UV-curable methods (photopolymerization), but all of them mention that to make a prepolymer or oligomer still use solvent and then evaporated before UV-irradiation process. Is it the only way or we can make prepolymer or oligomer without use solvent?
I want to use alkoxide initiators for the polymerization of styrene. Can i use high vacuum techniques for the sodium alkoxide initiators.
Im trying to react C5 and acrylate monomer. As we know, acrylate monomers are esters consists of vinyl group. What kind of reaction takes place between C5 and vinyl group and how is the reaction occur?
I tried to make crosslinked EPDM (DOW EPDM 4570) which dissolved in toluene with 3three wt% BPO (85 C, 24 hr) as an initiator.
But, I couldn't get the crosslinked polymer, and it was all dissolved in toluene.
I couldn't find the reason why I can't get crosslinked polymer?
Would you let me know what I need to do to get partly crosslinked polymer?
I have this polymer with some amino functionality, but I need to know how much functionality it has. I am given an amine number of 2.5-3.3, and a viscosity range of 1000-2500 cts. I wish I had the molecular weight. Do I have to know how much titrant and how much sample they used to get this number in order to do the conversion?
In my team, I'm now responsible for synthesizing a strong anionic-exchange material, which involves the task of attaching tertiary amine functional group on a poly(vinylbenzylcholride-co-divinylbenzene) base, using triethylamine (TEA) in varied volume of toluene.
I'm having trouble with the washing step, which would remove the residual TEA. I tried using HCl 2% (v/v) in acetone, but I could not control the formation of the resulting ammonium salt, which would precipitate and deposit on my synthesized material.
Please suggest me any other appropriate cleaning method. Furthermore, I'd like to ask a detection method for residual TEA, since I don't know whether scanning for its absorption peak in the 210-220 nm region is the correct way or not.
Many thanks in advance.
I can make it clearer if the descriptions are not detailed enough, so please don't hesitate to pop in your questions.
We would like to verify whether a polymer alternative that we made truly underwent the process of photopolymerization.
Percentages of chemicals(Sodium Hydro oxide and sodium silicate) to be used and what concentration we need to maintain to attain the optimum Results..
Is Reaction between PropylMethyl Acrylate and Ethylene Methyl Acrylate Possible? And if its possible, what are the expected result ?