Elastomers - Science topic

Hi Everyone,

I am going to blend different polymers together and I am looking for a suitable compatibilizer for each of them.

- blending PP and HDPE

- blending HDPE and TPV

- blending HDPE and elastomer

the compatibilizer for each of them should have FDA approval.

Thank you in advacne.

Best regards,

Omid

I have recently heard about the complete phaseout of ALL perfluorinated compounds, not only surfactants but also all polymers, including copolymers containing minority comonomers with a single perfluorinated alkyl groups (CF3 or CF2). My feeling that it is an overreaction. In certain applications polytetrafluoroethylene, FEP, and fluorinated elastomers are are virtually irreplaceable, or only with much worse performance. In other cases the "best available" technology was accepted until better were found. I think the same should be done here - or at least the social and commercial costs of a (worse) replacement should be considered. Human ingenuity is powerful, but we cannot invent a new nature. Fluorine has a special place in the periodic system, which cannot be simply replaced. I would be happy to hear the opinion of those, who can tell not only what should be banned but also can suggest viable alternatives.

Hi dear all,

Is there any way to reduce the MFI for Epdm/pp blends with Phenolic Resin? It is desired to be operated in extrusion yet, the material has high flow rates so we would like to alternate it while keeping mechanical properties as it is.

So far, the additive level adjustment seems to be the most common answer.

Thanks in advance,

Dear everyone,

Currently, I am studying a paper concerning the fabrication of elastomers without covalent cross-linking and the verification of their mechanical properties. The authors extracted the sol fraction out of the elastomers and used them for swelling test. I wonder why the sol fraction can be used for such a representative. And why isn't the bulk elastomer used for the study? I have encountered these questions for days, and I still could not find a firm conclusion for that.

Thank you!

Hello Everyone,

I have a subroutine for Elastomeric bearing. I want to use it for simulation in ABAQUS. For that, I need to define two noded UEL and assign them between two 3d Objects, as shown in the attached figure (UEL.PNG). As UEL can define only in the Input file, I am confused about how to assign the UEL between two objects. can anyone help with this? I have also attached the input file for reference.

Thank you

I have been studying DLP/LCD 3D printing elastomers. I have tried using different UV curable materials such as HEA, EA, or polyurethane acrylate (PUA)-IBOA to fabricate UV-curable elastomers. The extension of the elastomer is up to 100-900%. However, the 3D printed structure (such as a lattice structure) cannot withstand twist or tension loads for cycles. I have tried using UV light to cure the 3D structure from 30 minutes to 1 hour, but the performance was not improved. How can I improve the mechanical performance of 3D printed elastomer structures? Thank!.

These filment things appear in many images of my samples and I have no idea what they are. Need help, please.

I am using some industrial cable waste and there are two types of jelly that are inside these cables to avoid damage to small fibres inside them. They are,

1. Hydrotreated paraffin base distillate and polymethacrylate resin.

2. Hydrotreated paraffin base distillate and thermoplastic elastomer.

We tried several ways (with commonly available commercial materials) to wash them, but none of those techniques was successful. I am expecting some advice on techniques that can use to wash them.

I am trying to build a DEA soft robot actuator using VHB/silicone and carbon grease, it's now operating in HVDC 6~7 KV, but people already achieved <3 KV. Could anyone please share, what are the governing factors to achieve an efficient DEA actuator? Your expertise is highly appreciated!! Thanks.

Rubber and rubber-like elastomers fail in a brittle manner. Therefore, I have some idea how the defect free bulk material fails. I have seen such failures in tension. But I have never seen any compressive failures. Has anyone found a photo of cracking of rubber-like materials in uniaxial or planar compression? Or can anyone make such photos?

Dear all,

I have done a dynamic test on elastomer Agulus materials used for 3D printing to investigate the mechanical properties of this material, for instance, Storage and loss modulus, but the result is showing that the loss modulus is higher than the storage modulus, is this possible?

I attached both graphs, with the green coler being Loss modulus while the red is storage modulus.

Dear Researchers :

Can someone teach me how to go from a Concentration given in wt.% to a concentration given in phr ?

Or the two are numerically equivalent ?

I'll appreciate it !

Regards !:)

Generally, In thermoplastic polyurethane elastomer (TPU), polydiol chains, known as soft segments and diisocyanate chains, called hard segments are arranged in a certain ratio. This hard and soft segment ratio in TPU governs its properties and application. Therefore, it is logical to determine the ratio of the hard and the soft segments in TPU.

Hello to everyone,

for my PhD research, I'm studying the fiber-reinforced elastomeric isolator. In particular, it's a study on low-cost devices for developing countries.

I would like to know in which countries are allowed their unbonded applications (without any steel support, in direct contact to the foundations and to the superstructure).

If any, are there codes with minimum requirements and design prescriptions?

Thanks in advance for your help.

Best regards,

Gaetano

I intend to conduct nanoindentation tests on elastomers. However, the surface roughness influences a lot the results (ie. elastic modulus or hardness). Is there any way to reduce roughness of elastomers?

because the pdms with benzonyl peroxide, as the article says, does not crosslink the polymer pdms without any dopant at 150 degrees 160, 170 and 180 degrees, there is some other crosslinking agent or curing agent for dimethicone (pdms) other than sylgard that is very expensive?,I study physics but I thought it was going to be cured with radical peroxide but it did not polymerize, I have even tried it for 1.5 hours with relation 10:1 ,thanks.

I am studying a thermoplastic polyester elastomer. I want to get a prony series from the data available that can be further used for FEA simulations. Is there any way to obtain the prony series parameters from the available data.

(Data sheet is attached)

Dear Researchers :

Does anyone have experience or knows specific works about the study of Mechanical Properties (i.e. , tensile strength, yield stress, limit of elongation (%), elastic modulus, etc.) of Polymeric Matrices...

These could be:

- Polyethylene/Polypropelene (PP)

- another PP or PE co-polymer, ter-polymer, etc

- EPR

- EPDM

- HDPE, LDPE, LLDPE

or other plastics or elastometers blends

but when Al2O3 particles (or nps) are embedded in the matrix ??

I will appreciate any help, or any direction,

Best Regards !:)

I am currently facing an issue regarding the control of the humidity in my workspace. I am using a PU adhesive to bond to elastomeric substrates and i was wondering if i could decrease cure rate for better handling of the operation without hindering its mechanical characteristics ?? I considered using MEC to wipe substrates before adhesion but i don't know if it can provide required results.

I would be grateful if you could provide me some insight into this subject .

How do you understand, by your experience the areas of application of 3D printing with the use of plastics (biopolymers)? Which areas of practical application are likely to become the fastest and achieve breakthrough value? I mean real industrial applications. I suggest maintenance (spare parts, consumables) as the direction. Machine spare parts can be printed without involving the supply chain. This applies to elastomeric elements, seals, shock absorbers, bearings, etc. The 3D printer can additionally secure the supply of critical spare parts that do not need to be kept in stock and can be restored in a short time.

What other directions of mass use of 3D printing in FDM / FFF technology (polymers) do you see for which research is worth doing?

I am trying to prepare transparent thin film from elastomers. For this application, the elastomer must be optically transparent.

We have tried to synthesize the silicone gel elastomer (HTV silicone ,  platinum-catalyzed addition curing) by mixing the PDMS-Vinyl terminated,poly(methyl hydrogen siloxane),PDMS-Hydrogen terminated and platinume complex solution;and then leave them in elevated temperature;

We have tried different component ratio,different reaction temperature and different time lapse,but we havn't seen any curing yet!so I wanted to ask if any one can help us by pointing our problem or suggest a starting formulation?

I have this basic question, since some Thermoplastic polymers such PE, or Polypropelene ..

PE via techniques of Cross-linking for example, can be turned to a Thermosetting polymer, ...

Any Thermoplastic, in theory, can be turned to a corresponding Thermoset polymer ?

Regards !

I can't model the LRB between deck and column with 2 draw joint.

I don't know how much to consider the distance between the two nodes that I want to put the elastomer.

when I put 2 nodes in 60cm, Analysis gives a dead load case error and when I put 2 nodes in 150cm, analysis done. but results sensitive to distance of 2 nodes, and bending force doesn't reduce enough.

Recently, I have been studying the dynamic properties of theromplastic polyurethane elastomer in the molecular level with the help of lammps. However, when the molecular arcitecture modeled in the Materials Studio with PCFF forcefield was converted into the Lammps by the tool called “msi2lmp”, there appeared some error information, such as“Unable to find bondbond data for cp c2 cp, Unable to find bondangle data for cp c2 cp”, etc. Could anyone tell me how I can get the complete pcff forcefield datafile? I'd really appreciate it if you give me any advice or tutorials.

Currently, I am working on a Rail-Structure-Interaction live research project using wireless sensors, which need to be compared with numerical analysis.

I am trying to find the amount of force transfer from rail to the sleeper, sleeper to deck and deck to Elastomeric bearing and then to the pier.

Any Idea or reference for Instrumentation will be of great help.

Thanks in advance.

From some of my tensile strain-stress curves, the load keeps increasing at higher extension after yielding as in 1.png. This is really wired. Anyone knows what's wrong?

And since the load is really small generally, I cannot see any sharp load reduction at fracture, making me confused about the final elongation. Like in 2.png, fracture actually has happened at around 300mm but no load drop. Is this due to instrument accuracy or something?

Hello all,

I want to simulate a Dielectric Elastomer Actuator DAE (an electrostatic-Structural analysis). I want to apply various voltages and frequencies into the DEA in the form of sine wave. Any help and guidance will be much appreciated as my knowledge in MAPDL is quite limited.

Kind regards,

In metals and alloys, generally when the stress generated exceeds yield (ductile) strength, it is implied yielding or failure occurs.

Similarly, in the case of finite element analysis of elastomers, what is the best parameter used to predict failure of elastomer under static loading?

1. Stress

2. Strain or

3. Strain energy

Third, similar to the Goodman relation in metals, what is the industrially used relation for fatigue life prediction of elastomers?

The material does not satisfy the requirement of Hooke's law which is based on linear materials. I would like to know different means of determining Young's modulus of the elastomer.

Want to reduce the Hardness of TPU. As TPU comes in a granular form incorporating plasticizer is difficult. What methods can be used to incorporate plasticizer in TPU?

I'm characterizing Polymer and Elastomer, Now I need to evaluate the data for the FTIR mapping with software. Is there any open source FTIR data analyzer

Kindly please add link for the FTIR free software

Hi Dears,

Is there anyone to know about the commercial catalysts for the polyester polyol production? 

Regards,

Alizadeh.

I am trying to simulate Dielectric Elastomer Actuator by applying cyclic loading onto the Elastomer in terms of (various voltages and frequencies) and find the deformation of the Elastomer, I already defined my material using the curve fitting tool in ANSYS you can see that in the attached photo. Now, I Frankly don't know how I can preform this simulation I can not find any references or tutorials.

If you can help me with anything will be much appreciated. Thank you

P.S: The material I am using is Sylgard 184.

Thank you again!

hello, I'm performing an experiment about liquid metal embedded elastomer and I would like to know if someone ever get a way to find the concentration of the mixing. I'm using droplets number to determine that is not really formal

do someone have another interesting way to do it ?

We are using an Ogden hyperelastic material property to model an elastomer. The elastomer is a cylindrical bushing. Our simulation is static (a sine input in semi-static condition) so we are trying to use either Static (nonlinear) or Implicit to solve it. However, every time we run it using Implicit or Static we the analysis exit with an error saying it has “Time increment required is less than minimum specified”. We have decreased the minimum increment but we still get this error. However, when we run it in Explicit mode it works fine but it takes a long time. Is there a way we can run this model using Implicit or Static (Nonlinear on)?

I’ve recently come across some silicone suction cups that are labeled as non-marking. I’m wondering what makes these suction cups different from other silicone suction cups? I’m sure it has to do with free oligomers but I’m curious if there is anything specifically different in the manufacturing process or the chemistry behind it.

To assess the discolouration effect of food on elastomers, the colour must be assessed. One way is by the use of a spectrophotometer. But the latter only measures liquids or large objects. Does anyone have any information on that?

Hello every one,

I am doing analysis of Bridge in which elastomeric bearing is modeled as link element between Deck and pier bent. Pier bent portal consist 2 pier and one cap beam on which elastomeric bearing are resting and on elastomeric bearing bridge deck is rest. I am doing non linear time history analysis.

Now (1 )due to elastomeric bearing, moment/forces are not transferred to pier hence bottom moment of pier has not reached Mp value and stresses in pier is very less (at least half of yield stress of Concrete)

(2) Joint Forces at link bottom has reached maximum level of forces and for bearing perfect elastoplastic force displacement curve has given as input of link

(3) Even if pier concrete has not reached at yield stress level CSI Bridge & SAP2000 showing hinges from IO to CP at various time steps.

Why does SAP 2000 Showing hinges in pier even if pier has not undergo plastic moment? Does it is due to yielding of Bearing

I used Moving Die Rheometer (MDR) to determine cure conditions for vulcanization of a HNBR and Tan delta curves using different temperatures.

According to some papers, lower Tan delta value at certain temperature means higher resilience for rubber after curing. In this case, Tan delta value for 170-degree C was lower than 160-degree C with both showing proper vulcanization curves. After cured, I tested tensile strength for both, and they show not much differences in stress, strain, and elongation %.

- Does higher resilience reflect higher tensile strength?

- Do they even have a relationship at all?

- How can I determine the cure conditions to increase elongation? Thanks

I am trying to make a conductive silicone composite (1k-1Mohm) using sylgard 184. I am using a probe sonicator (dispersed in heptane, chloroform or THF) and planetary centrifugal mixer but can’t seem to get any resistance measurements at low percentages (<3%). I want the percentage to be low because I need to spin coat the final material. Is there an optimal MWCNT or even SWCNT size that would be best for getting a minimally conductive silicone composite at low percentages?

Hi. Can anyone please help me explaining the difference of viscoelasticity behavior of thermoplastic, thermoset and elastomer in terms of effect polymer structure and temperature? Or if anyone can provide me the article/journal/research

I have used the default value and the model is not yielding proper results. Kindly help me out.

Dear all. With a group of students from the Delft University of Tech. we are working on a concept-product for the human ear. It should become a product that can be custom-fitted to the ear by the consumer at home. We have already experimented with thermoplastic polymorph, but there occurred 2 issues/challenges:

1. In solid state it was too rigid - and therefore not comfortable - which led to looking into elastomers.

2. It's melting point is too low - meaning it took a long to solidify.

Would you have any suggestions (materials or persons) that could help us in our future endeavors?

Sincerely,

Wouter

I am looking for the lower limit value of the diesel aniline temperature point the elastomer can withstand before the diesel starts breaking down the elastomer. I'm unsure how to complete this because most of our rubber testing is done on raw, uncured rubber, so i am not sure which material properties to track/compare before and after the test.

I want to create a soft protective coating for some neodymium magnetics with minimal reduction of the magnetic field strength. Does a product or a method of making an elastomer composite already exist like this?

I am looking to test thermal expansion forces of small elastomer particles (~1mm diameter) and am planning to use Dynamic Mechanical Analysis for this test. The current plan is to machine a shallow cylindrical aluminum pan which I will fill with these particles, sized so that the upper compression plate of the DMA can fit cleanly inside like a plunger on a piston. This is to minimize radial distortion as the particles will be constrained within the dish. Tests will be isostrain temperature ramps to measure the thermal expansion forces of these particles as they increase in temperature. Assuming we perform this test many times and account for voids between the particles by assuming some random packing factor, is this a reasonable approach to collecting this force data? Measuring individual particles seems like the measurements would be too close to the minimum sensitivity of the instrument.

I am interested to hear about the concern of adult amphibian marking by elastomers (visible implant elastomer). I have seen an article that concludes that this technique is reliable, and others that conclude otherwise (e.g. "VIE tags, as individuals were correctly identified only 18.4% of the time" Brannelly et al. 2014).

Has anyone used them in thick skinned species, such as those of the genus Rhinella?

My bachelor thesis was to manufacture a thermoplastic elastomer using recycle rubber gloves (rRG) and polypropylene. I got a problem when I solved rRG in xylene because it hasn't solved but it's swelled. I has read that rubber was solved in petroleum eter, so why it can't solved in xylene? I'am using xylene because it was good to solved polypropylene (matrix polymer that I used). Thank you.

Is there any standard for abrasion testing when two metals are rubbing?

Or how do we calculate the wear rate when two metals or metal & elastomer are in sliding contact

i have two metals parts which are sliding on each other, i need:

1. how to select the material grade combination

2. calculate the life

thanks

I need to find the excitation frequency of the system (rolling stock+steel sleeper+elastomeric rail pad) which is in immediate contact just with the width of sleeper. The issue is about proving the reduction in transmissibility coefficient over the bridge by replacing the rail pad placed between sleeper width and beam of the bridge with undersleeper rail pad placed along the length of sleeper between sleeper & beam of the bridge

Hi,

I've been searching for the correct equation for my situation.

My sample is a ~1mm elastomer film on ~300um PET substrate.

I found several old threads about quantifiying internal stress in coating/thin film but they don't really apply for my situation.

Any help is appreciated. Thanks!

I would like to calculate the stress strain curve for Cellulose nanofibril using GROMACS. How can I calculate stress strain output steered MD simulation?

We have some O-rings made of perfluoroelastomer (FFKM) from a different vendors and we would like to determine the cross-linking density to correlate with performance. Can anyone suggest a suitable technique?

A Previous well-known technique is TG/DTg but the fibers decompose with the rubber on raising the temperature so it won't work what else characterization technique we can use for this particular.

Is it possible to machine elastomer using abrasive water jet machining?

I have an application where I need to grease a "polyester Polyol" type of Polyurethane. The application requires excellent adhesion, wear resistance, and water wash-out/spray resistance, with good boundary lubrication requirements (adequate maintenance isn't always guaranteed in the field).

I know that lithium soap/complex greases with a mineral oil and MoS2 are adequate for the job, but I'm also interested in Calcium Sulfonate/mineral oil-based MoS2 greases for their superior lubrication/water resistance properties.

Is Calcium Sulfonate chemically compatible with "Polyester Polyol" types of Polyurethane elastomers? Or will it cause the Polyurethane to swell, harden, break down, etc?

Thanks in advance for your help.

In general, to characterize the time-dependent (Visco-elastic) properties of filled- rubbers, different tests such as stress relaxation/ creep/ strain-rate sensitivity are carried out in "simple tension" deformation mode. Why are other deformation modes not considered?

There are really few works on magnetorhelogical hydrogels. What is the difference between MR hydrogels and MR elastomers?

I'm searching a elastomer material can be used below -200℃, i.e. glass transition temperature below -200℃.

I'm studying the low temperature resistance elastomers. But I didn't find any good method to decrease Tg of the materials, by chemical modifications or by reinforcement. I need help.

I am modelling an elastomeric bearing in ansys apdl but the elastomer does not bulge under compressive load as it should. it "splashes out" under any significant loading. is it the loading problem or does it originate from the model?

when mSEBS is subjected to base catalyzed hydrolysis, it got crosslinked and loses its elastomeric properties. can anyone tell me why this is so? and to much extent hydrolysis will never effect its elastomeric properties?

Hello, I am trying to contact the researchers (Pengning Zhang; Lin Li; Juanjuan Zhang; Chong Gao) of the article “Vibration and noise reduction of HVDC anode saturable reactor by polyurethane damping elastomer”. We tried through the emails we retrieved through the internet, but we did not get any feedback. The authors are linked to the North China Electric Power University and the State Grid Corporation of China (China), but we also cannot get in touch with these institutions. Does anyone have any suggestions on how to contact them and if this is possible.

we are having the system polyol with 5 second cream time but after 20 second the rate of reaction rapidly going up and the gel time close to 40 second , So, how we can control the rate of reaction around 50 second of gel time.

These polymers consist of coil-like polymer chains: (a) Thermoplasts (b) Thermosets (c) Elastomers (d) All polymers

I have to test the ultimate flexible strength of polycaprolactone sample prepared by 3D printing technique. But the material is not going under fracture for a very high displacement of load. And ultimately my sample is dropping down from the supports. Please suggest me any way to do flexibility testings of the samples.

the tensile strength of a set of blends prepared from two elastomers is well higher than parallel model. what could be the possible explanation for the same?

I need to know basic raw material and one thing is troubling me than would I be able to melt the natural rubber and synthetic rubber.

If I prepare, for example, PDMS nanocomposite with 40wt% or 50wt% MWCNT, what will happen to the electrical conductivity values of this nanocomposite?

my work is seismic behavior of simply supported composite bridge deck. i modeling the superstructure of bridge deck on csi bridge but i dont know how to model the bearing and how to support the superstructure without model the pier???

I'm currently working on a project involving TPE Filament (3D Printer) as my base material. The manufacturer doesn't have the data of Young's Modulus that I need. What is the procedure for finding Young's Modulus of this material? What is the standard geometry of the specimen for testing elastomers?

Currently I only have access to a Tensile Test Machine, Hardness Test Machine, Impact Test Machine.

Thank you.

To my dearest researcher and academician,

I have a question - How much wt.% DBTL catalyst is to be added to synthesis polyurethane gel/elastomer in common practice?

I hope you guys can share your knowledge and experience regarding to this.

Thanks in advance

Does all the elastomeric polymers will have thermoresponsive shape memory?

Since they can be fixed into a temporary shape by deforming and cooling below their glass transition temperature Tg. and can recover the shape by heating above Tg....

please provide your views...