Polymer Characterization - Science topic

I believe the above answers are all possible. You may also look at the gelatinization aspects of starch.

I am trying to find a stain(dye) that might help identify spider silk but nothing clear at the moment. Does your department or another department do a variety of tissue staining? If so, I can suggest somethings to try.

It's hard to tell without knowing your formulation, but I suspect you are starting to see fusion at the 6 minute mark, not degradation. PVC formulations are based on 100 phr PVC. If you have "45 phr", then it sounds like you are using a weight percent and not actually phr. If the remaining 65% is stabilizer, filler, lubricants, process aids, etc. then a delay in fusion and the absence of a loading peak could make sense.

I currently study film formation of PVDF and copolymers. The whitish appearance is in fact due to surface roughness and/or air bubbles inside the membrane. The yellowish discoloration seems to occur due to degradation induced by the selected polar solvents and heating at low temperatures to evaporate them. Based upon literature (10.33736/jaspe.163.2015) there is a strong possibility that the lone-pairs on oxygen atom existing in solvent (DMAC, DMF, DMSO) induces the removal of a hydrogen atom from the PVDF chain that is followed by double bond formation and fluorine removal. The degradation mechanism should be similar to the one with NaOH treatment in the paper (available in Reasearch gate).

Yes, polypropylene sheets can be manufactured using a biaxial process, which involves extruding, quenching, and biaxially stretching the sheet. This method enhances the mechanical and optical properties of the polypropylene, making it suitable for various applications.

Dear Raheem:

I pay taxes in Canada.

No worries. I'll attempt to publish via Nuclear and Welding in the near future.

Sincerely

Paul Cheng

Enclose crystalline structure of what we are doing. Fine grained base to base. No HAZ.

I'm sorry that it's taken me so long to thank you for your help.

Since then we have explored some of the possibilities you laid out in your respective responses that pertain to our system. But the work is still going on. Thank you for your insights!

Matthias Heck Petr Lepcio

Ricardo Noe Meza Puebla Gel permeation chromatography is suitable.

I agree with your estimation of the appropriate gap as a three characteristic size of particles.

If you want to measure the ionic conductivity of the polymer (Membrane), two electrode electrode set up like Ag/Polymer/Ag or Pt/Polymer/Pt can be utilized where the measurements carried out using the electrochemical workstation by the technique like PEIS.

Further their electrochemical properties examined through CV,CD studied using the coin cell set up to study their viability like battery measurement (Cathode/polymer/Anode).

Incase of the solid, the polymer composite can be used as the working electrode, where it can be prepared and coated on substrate and the Ag/AgCl or Hg/HgO as reference electrode & Platinum electrode or Gold as the counter electrode. The measurements like CV,CA,CD, Impedance can be carried depends upon the application.

Dear Sergei,

Please take a look at this paper:

You might find it useful for your experiment.

Best of luck

Dear Dr Islam

Distinguishing between different types of copolymers, such as random, block, or alternating, can often be challenging but can be achieved through a combination of techniques and analyses. Here's how you might differentiate between these copolymer types:

I think that this article answers very well to Your question, by considering different materials for 3D printing in dentistry (together with their limitations):

Another interesting literature review:

Best regards,

AP

I think that this article answers very well to Your question, by considering different materials for 3D printing in dentistry (together with their limitations):

Best regards,

AP

Hello, Vadym Chernobrovchenko.

A diffraction pattern of a crystalline material shows that narrow peaks in certain 2theta angles, as you may have seen before. The peaks in XRD pattern represent the crystal planes of a crystal structure, check the image attached. Once you have an amorphous material, the structure is not periodic, and there are no crystal planes. That's why that peaks don't appear. From your pattern, you can confirm it's not a crystalline material, but I don't have expertise in polymers, so I can't say anything beyond that. Feel free to reply and ask about further results.

Sincerely,

Ricardo Tadeu.

Vadym Chernobrovchenko

I worked for thirty years at the Sumy State University. He contributed to its development from a branch of the Kharkov Polytechnic Institute to a classical university.

The amorphous halo in the diffraction pattern is determined by the lengthchain and interchain distances. The complex shape of this halo can be approximated by the superposition of two or more Gaussian curves with maxima, the superposition of which can be represented based on the analysis of the X-ray diffraction patterns of the crystals of this polymer.

Dear friend Vipin Cyriac

The behavior of polymer blends can vary depending on several factors, including the specific polymers involved, their molecular weights, the solvent used, and the processing conditions. In some cases, immiscible polymer blends in solution form can exhibit improved miscibility in the solid state after the solvent is removed. This phenomenon is often referred to as solvent-induced miscibility or solvent-induced phase inversion.

Solvent-induced miscibility can occur due to various mechanisms, such as the formation of interdiffusion layers between the polymer chains, the plasticizing effect of the solvent, or the creation of new interaction sites between the polymers. It is important to note that the extent of miscibility achieved depends on the specific blend composition, solvent type, and processing conditions.

While there are numerous research studies investigating the effect of solvent-induced miscibility in polymer blends, it is recommended to refer to scientific literature for specific examples and detailed information. Some relevant references that discuss solvent-induced miscibility in polymer blends are:

1. Rong-Ming Ho, et al. "Solvent-Induced Miscibility in Immiscible Polymer Blends: A Review." Polymer Reviews 52.4 (2012): 339-376.

2. Alemán, José, et al. "Induced Miscibility in Polymer Blends: The Power of Binary Solvent Mixtures." Macromolecules 51.1 (2018): 1-15.

3. Zou, Weike, et al. "Enhanced Miscibility of Immiscible Polymer Blends Induced by Solvent Vapor Annealing." Macromolecules 43.16 (2010): 6769-6775.

These references provide insights into the principles and mechanisms behind solvent-induced miscibility in polymer blends and offer specific examples and experimental data. It is advisable to consult these sources for a more comprehensive understanding of the topic.

Dear Nekin,

Nice question, I believe that it will be difficult to find a well-supported answer!

Hereinafter there are only few considerations from my part.

a) The price of 3D printing composite filaments is determined by a multitude of factors (nature of polymer matrix, fillers, reinforcements, additives, capacity of production, and so on).

b) Traditionally, the twin-screw extruders (TSE ) can be successfully used to produce various composites by melt-compounding, of good quality and with high throughput, which can be proposed for 3D applications.

c) Unfortunately, TSE are less adapted for the direct production of 3D filaments of high quality, even that there are few suppliers that can propose this kind of equipment for one step production, designed mostly for academic research/low-capacity production (e.g., Lestritz, ThermoFischer, etc.). Maybe other RG collegues can help more with information...

d)Please take a look :

Thermo Scientific Process 11 Lab-scale 3D Filament Production System

e) For the production in big quantities of 3D filaments it’s generally agreed that the production in two steps (1. fabrication of composites with TSE; 2. the extrusion of 3D filaments, e;g., using a single screw extruder) has a large number of advantages. I will refrain from more comments...

f) Function of requirements/ your application (type of composite), I suggest you use as starting point the price of 3D filaments/composites that look similar/satisfy your needs, and which are already commercialized in the market!

Success in your R&D project and best regards,

Marius

The Digital Image Correlation (DIC) technique is a powerful tool for analyzing the deformation and strain of a rough surface. GOM Correlate is a popular software package for analyzing DIC data. Here is a general procedure for using GOM Correlate to analyze a rough surface using DIC:

This general procedure should give you a good starting point for using GOM Correlate to analyze a rough surface using DIC. However, it is important to note that the exact procedure may vary depending on the specific surface and application being analyzed.

To identify Fe-rich phase with SEM no staining is required.

Measuring the gel fraction is important in determining the monomer conversion in polymerization processes. The gel fraction is defined as the fraction of the polymerized material that has formed a three-dimensional network, which is insoluble in the solvent used for polymerization.

It is important to note that the gel fraction can be affected by various factors, such as the type and amount of initiator used, the temperature and pressure conditions, and the molecular weight of the polymer. Therefore, it is important to carefully control these variables and standardize the measurement procedure to ensure accurate and reproducible results.

FDM 3D printing materials are ABS, PLA, and their various blends. More advanced FDM printers can also print with other specialized materials that offer properties like higher heat resistance, impact resistance, chemical resistance, and rigidity

Yes,it can

Did you find a solution for your problem? If you find a solution can you tell for me. Because I am also doing similar kind of problem in my hyper elastic model.

Noor ul Ain

Polyacrylamide has the basic properties of the amide group. Phenolic red acid-base indicator. Depending on the pH of the aquatic environment, it acquires a different color. So, if you want to bond polyacrylamide and phenol red, they must have different + and - charges. In an acidic environment, polyacrylamide will have a + charge on the amide group, and a - phenol red charge on the sulfo group.

Vadym Chibrikov Thank you so much for your previous answer.

I found Kapton (Polyimide films) are very flexible. So I tried to fix it on glass substrate (using kapton adhesive tape on four sides). Still it is not very planar (warping here and there) and could not get good patterns over it.

Also, I am still struggling to find a way to remove it from glass substrate at last and stack it inside a PCB (multilayer).

One easy way would be to do it optically. Just take a high quality image of a crosssection of your pellets and use for example the free software imagej (particle size determination).

For an isotropic pore structure the "areal" and "volumetric" porosities stay the same.

Just take care when preparing your crosssection that you don´t introduce to many artefacts, maybe crush you pellets after cooling it with N2.

This ofc only gives you the total porosity, you can´t differentiate between closed and open pores. Ofc you could also think about filling your accessible pores with for example resin before preparing the crosssections. I hope this helps

you can use CF3COOD/CDCl3 (2/1 v/v)

Hello Noor,

The magnitude of Zeta potential value 30-40 mV means moderately stable, when the value is above 40, its usually stable.

So your copolymer is moderately stable.

Good day! Here I found brief and complex explanation on reflectance and transmittance phenomenons:

You need to define a Displacement loading for the upper plate (14 mm), or there's no deformation in your model.

Good day! You may check swelling degree, dry density, storage and loss modulus, transparency. Regards

Dear Foroogh Khodadadi, the essential key is the hydrophobicity of the polymer matrix. It seems that polysulfone copolymers and composites are the most favored. Please have a look at the following documents. My Regards

Vadym Chibrikov Thank you for your curiosity!

Tzero Lid was pressed using the DSC Tzero Press. What do you mean by "pressing should be done in triplicate" ? Maybe it helps to know, that many of my Tzero lids were displaced and pressed out. It was not a singular event. Additional info, I use the black pressing die with the concave top.

The material is powdery formulation of zein and glycerol (around 20% glycerol w/w). heating rate 15°C/min. Preliminary measurements (which didn't show lid displacement allowed me to tell that there is some amount of water contained in my material, which results in an endothermic deformation during the first heating cycle. second and third heating cycles usually coincide, suggesting that all water evaporated during the first cycle and that the curve form the second (or the third) cycle is "analysable". Note: the material becomes sticky when in the viscous state, so the lid isn't fully pressed out, it just stays half open, oblique, with some material peaking through.

https://folk.ntnu.no/deng/fra_nt/other%20stuff/DSC_manuals/QDSC/Preparing_DSC_Samples.htm this manual suggest using samples 10 - 20 mg for Glass Transition measurement, which is what I'm aiming to analyse here.

Dear Franklin Uriel Parás Hernández, both degradation and crystallization are behind the change in color aspect. My Regards

The norm ISO 17556 refers to the measurement of the BIODEGRADABLE fraction of C in your polymer. It is a respirometric test. You need the Gas Endeavour equipment: https://bpcinstruments.com/biodegradability-compostability/?gclid=CjwKCAjwquWVBhBrEiwAt1Kmwk-g8s-R_YkbXphn_RMwcc6592PGOo2BeENbMjmByY5bx19lRmw6jBoC7CIQAvD_BwE

Please contact Alberto Benavides for a quote: ab@bpcinstruments.com

In the observed frequency window your molecules do not interact much and the material behaves more viscous. If you go to higher frequencies, G' and G'' approach and if you go to even higher frequencies, they'll probabely cross (G'>G''). This is related to your molecules entangling. If they are entangled, they can't react to deformation at higher frequencies as a liquid any more. The entanglements are a kind of physical crosslink at high frequencies, while at low frequencies the molecules can slide past each other.

Dear all, please check the following RG thread and the attached files. My Regards

Dear Foram Dave, it is well known that nucleation reduces spherolites size, hence important enhancement of properties are imparted to a polymer known by its high and large crystalline size domains. Please have a look at the following attached paper. My Regards

water, methanol, DMSO, DMF

Dear Foroogh Khodadadi, if you are suspecting Hydrogen bonding between SO2 and OH groups, sulfone group is a poor H-forming group due to the orientation of H-donor-acceptor counterparts. Please check the following documents. My Regards

PEDOT Mol.weight ~= 1000-2500 (with Degree of Polymerization of ~15) and length of polymer ~3-7 nm

PSS Mol.weight ~= 400 000

Clevios P 1.3wt % PEDOT:PSS with molar ratio of (1:2.5).

[ClevioPH1000 has higher Mol.weight than CleviosP (as Per dynamic light scattering (DLS)]*

References

2009-Microscopical Investigations of PEDOT:PSS Thin Films

2012-PEDOT Nanocrystal in Highly Conductive PEDOT:PSS Polymer Films

*Higher PEDOT Molecular Weight Giving Rise to Higher Thermoelectric Property of PEDOT:PSS: A Comparative Study of CleviosTM P and CleviosTM PH1000

The Flexdym polymer created by Eden Tech is a great alternative PDMS. It's biocompatible, transparent, gas permeable and can be molded in just a couple of minutes. And it binds to a variety of substrates including PMMA. Here's a link: https://eden-microfluidics.com/

Hello Noor,

100% Water absorption or sorption capacity of polymer signifies that it is so hydrophilic or porous material like sponge(depending upon the polymer) such that it is absorbing dry equivalent water of your polymer. Depending upon the application you will work on, such water sorption dynamics will decide it's failure or success. For example high water sorption in polymer electrolytes is considered good for physicochemical and electrochemical properties but it simultaneously affects the mechanical stability because of hydrophilic polymer electrolyte dilution. Even beyond some critical limits the electrochemical property compromises. If in case your application is different you can mention it in your comment and we can help you in a better way. I hope it helped. If in case you need any reference to support some proof of concept you can ask accordingly.

Dear Franklin Uriel Parás Hernández, literature is really rich with the subject you are studying. Please check the following documents. My Regards

Dear Milad, thank you for asking this very interesting technical question concerning the crystallinity of PLA (= poly(lactic acid)). In this context please have a look at the following useful research article which mght help you in your analysis:

Crystallization of PLA-based Materials

This paper has been posted on RG as public full text, so that it can be freely downloaded as pdf file. Also please go through the following relevant reference:

You just have to keep it in the nitrogen until no more bubbles are formed. When there is no more evaporation the two materials are more or less at thermal equilibrium and you can break your sample.

Dear Milad

The phenomenon of SCC normally occurrs in polycrystalline metallic alloys that are succeptible to a combined of corrosion,i.e.,chemical dissolution, and a tensile deformation. Therefore,the possibility of SCC of PLA is slim to impossible .

Dear,

Some pigments can cause property modifications. I have tested PLA with different colors, and they have different tensile strengths.

For a polymer thermal analysis of the type of sample you have, you can first examine the TGA thermogram and identify the temperature range your polymer is stable. T hen, use DSC to heat to the temperature you are certain that your polymer is not degrading. Then, stop heating and cool the sample slowly in the DSC instrument, and start the heating cycle again. Any of those phenomena that are not reproducible, such as polymerization exotherm, impurity evaporation, anthalpic relaxation, etc will disappear in the second heating curve. Although impurity, including residual water, is a possibility for the second peak, what I am concerned is the slight exothermic event right before endothermic event that followed. Impurities usually do not show that. Have you made sure that you do not have residual lactic acid that did not polymerize?

Dear Franklin Uriel Parás Hernández, yes besicaly any thermoplastic polymer Can be crosslinked either by chemical, physical, or their combination processes. My Regards

I'm interested

Dear Jan David

Contact this address

Seamer Hill Stokesley North Yorkshire TS9 5NQ

link

One side is looking at density - whether it sinks or floats in liquids of different densities - water, alcohol, etc. Geologists do this with minerals - but they use bromoform (2.6 g/mL)!

the other side is using chemistry and solubility - flame tests to show presence of chlorine in PVC, what solvents different polymers dissolve in.

Dear Gabris Mahamid, the following documents are extremely important in case you want to go deeper in this subject. Also it is nice if you take a look at 'Israelchevilli's book' on intermolecular forces. My Regards

I'm not sure what are polar and dispersive components but you can calculate the surface energy of a solvent or a laminar solid (such as graphene) with MD. Although it's not as accurate as first principle calculations still gives you a reasonable estimate. If polar simply means the electrostatic interactions and dispersive refers to the vdW interactions, then they can be easily distinguished and calculated separately using GROMACS or LAMMPS.

Dear Sarah Sahota, there are many others options related to the electrospinning process and electrospinning solution properties. For the process, long spinning time and high diameter needle lead to thicker layers. Also solution conductivity may be another parameter to play on for thicker layers in addition to those you mentionned. Please check the following documents. My Regards

Slope gives the Young's modulus.

kindly check http://electrospintech.com/fiberbond.html#.YAXJMC0RpQI

It really depends on the nature of your sample and what size the micro spheres are, but as you are probably, aware having them all labeled with the same dye is not ideal. If your sample is well dispersed, you could consider flow cytometry, which works well with micro and large nanoparticles in my experience. You can sort particles passing the detector based on scattering and fluorescence intensity to get relative populations of each size but this doesn’t really work if you have a lot of aggregates.

Another technique you could use if you were working with fairly simple solutions would be a Nanosight Instrument if you have access to one and your particles were less than 3.5 micron.

And yeah trying to get particle size populations by UV Vis isn’t going to work out.

Possibly putting a drop on a microscope slide, taking an image and counting particle populations within an area analogous to cell counting is plausible at the micro scale.

Just getting differently labelled particles would simplify a lot though.

The first step is to use an option in Excel called "export file". Next, you choose one of the possible formats for the exported file. The most commonly used are either text (*.txt) with tab or spaces delimiters , or comma delimiters (*.csv).

The result is tables of data that you can use in any plot program available. As already noted by Oya Tagit, the most suitable program for scientific charts is "Origin". If you do not have it, on the website https://www.originlab.com you can start mastering it from the free version.

Link will be helpful to smooth XRD data by removing signal noise

You can estimate this from the DLS for some molecules. In essence a comparison for molecule families of size versus molar mass can then be use to estimate the mass from a measured size. However this is only an estimate, so there will be error associated with that estimate. There are a few models in the Zetasizer software, which you can download and install

Those are material properties and thus, in theory, they are the same value regardless of the volume of the samples measured. However, in practice, some internal defects may exists and these defect will, to some extent, influence the measured value by the difference in cross-sectional areas. For example, if you measure the storage modulus of exactly the same dimension samples, the values of two different specimens may still be different due to the shape factor difference. If one sample is near perfect and the other one might contain internal, undetected cracks or voids, the apparent cross-sectional area used to calculate the modulus may be the same but the true cross-sectional areas are different. Thus, the measured storage moduli of those samples are slightly different. The same is true for loss moduli. This is the reason why tan delta value is sometimes used to study Tg since tan delta is the ratio of the loss modulus against the storage modulus and thus eliminates the shape factor contribution, leading to a better baseline and sharper peak to determine the temperature.

Dear all, please check the attached files. My Regards