Questions related to Composite Resins
I have tried to cure the CNSL resin with a Hot air oven of 180 degrees Celsius. Still, I am not getting the proper solidification of the resin, the specimen which is kept in a Hot air oven is in a spongy state. I want to know the process/ steps/ procedure for curing the CNSL resin?
I am trying to fabricate PVDF membranes via phase inversion using 12 wt% solution in DMA. When I cast the solution on aluminum or Plexiglas plate using membrane applicator and put that into water bath, a thin uniform membrane does form; however, it gets permanently stuck to the aluminum or Plexiglas plate and cannot be separated. Can anyone describe the reasons and suggest some solutions?
I have stadium stairs made of concrete, and i need to pick an adhesive material that give a good bonding strength and can resist some environmental factors such as hot and cold weather without peeling off. ( ceramic- polymer composite).. I can،t wait to read your esteemed answers.
I am actually working on the Degree of Conversion of dental resin composites in my lab.
When I perform my FTIR analyses, I apply the equation to calculate the DC (the equation is not wrong, I have already checked that) and I always obtain some values turning around 6% for the best polymerized resin. However my curves appear to be good and the peaks are the same than everybody in the literature (1608cm-1 and 1638cm-1).
You can find in the attached file an example of the curves (red non polymerized, blue polymerized). Sorry if the legend is not in the good order.
Did anybody already have such a problem with the calculations and do you know how to change it ?
Thank you so much
Hello dentists, I'm wondering if pre-heating resin composite for luting use with Inlay and Onlay, may increase shrinkage phenomena or not ? If yes, is there any difference in shrinkage rate between nanohybrid resin composite and glass fiber-reinforced composite ??
Subgingival located cavity margin, inaccessible area. Complete isolation and dryness might be challenging.
Using Spectroradiometer to measure samples, can the color of the background be ignored?
Neutral gray, black, and white backgrounds are often used for color measurement. Will the use of spectroradiometers eliminate this factor?
I believe that despite the progress in developing newer dental materials esp. composites trying to mimic the role of calcium hydroxide and other dental products in forming dentinal bridges, these restorative materials can still illicit unwanted and unnoticed immune reactions within pulp when placed within < 1mm of RDT (Remaining dentin thickness)
I would like to know about anyone and everyone's opinion on this area. Thank you.
How the diameter of the fiber plays a role in interfacial bonding? If the dia of Fiber is small, we assume the matrix will completely adhere to the fiber. If the dia is larger, the same matrix covers the fiber. Whatever the surface area might be. It depends on how good it binds the fibers. But how this dia play a role in that?
Before and after curing, how moisture can play a role on the residual stress of a GF/PF resin composite material. What will be the effect of %RH on the composite before and after curing ? How does it affects its flexural properties ?
In order to find and fabricate a proper alternative counter electrode rather than Au or Ag in Perovskite solar cells(PSCs), the preparation of a convenient carbon paste is essential. This feature of convenience includes high conductivity as the first and most important one. Therefore, the binder plays a major role in the composition of the paste formula. Is there any polymeric/resin/composite that maintains the adhesiveness in the contact along with high conductivity(i.e low sheet resistance)? please do not hesitate to tell me your suggestions. I am keenly looking forward to it.
I m growing primary gingival fibroblasts, to test the cytotoxicity of dental composite resins. in addition to that, I have been doing gene expression analysis of these cells.
recently I have noticed that these cells act differently after passage 10?
Is it recommended not to use these cells after 10 passages?
In this composite, I have used bisphenol A epoxy resin (LY556 with epoxide equivalent 5.44 eq/Kg and aromatic amine based hardener Aradur HY5200 with amine value 630 eq/Kg.
How can I calculate the degree of cross-linking between this thermosetting system?
I have been trying some ratio's of Polyurethane Resin to Glass Fiber Cloth but my young modulus results come up medium to low (15.000 MPa circumf. and 8-10.000 axial) and my Poisson ratio quite high (0.4-0.7). Have you got any suggestions?
When surface modifying high K ceramic particles like BT, BST or BZT for use in a high k ceramic/polymer composite film, some researchers say they get higher permittivity in the final film when the particles' surfaces are modified with, for example, an acid like gallic acid or phthalic acid. At the same time, other researchers say a low ph causes barium to dissolve from the particles' surfaces and they talk like it is a bad thing and say the ph needs to be kept higher? Who is right?
I have results for dynamic strength of resin at a higher strain rate. I want to use these results to evaluate material properties of CFRP at the higher strain rate assuming fiber strength isn't affected significantly by higher strain rate. I want to use this model of impact loading test using a macro-scale model (Fibre and Resin are not separate) hence I can't use the Cowper-Symonds model. Also, how to implement this model for impact loading simulation? If using meso-scale simulation is one of the option what is the procedure that can be followed?
I want to compare three models will be used to make IC chip. The models consist of:
Model-1 (Silicon carbide, Resin and Silicon nitride)
Model-2 (Tetrahedral amorphous diamond, PVC and Alumina)
Model-3 (Tungsten carbide, Natural rubber and Tungsten)
The materials are used in each model to make composite. In Model-1, SiC is used as upper material, Resin as adhesive and SiN as lower material. Can PVC in Model-2, natural rubber in Model-3 be used in making IC chip? If not, please suggest other isotropic materials.
I have stress strain curve of resin at varying strain rates. I want to implement this strain rate dependent behaviour of resin for impact simulation of a CFRP tank in LS DYNA.
I have stress strain curve of resin (attached as image) at varying strain rates. I want to implement this strain rate dependent behaviour of resin for impact simulation of a CFRP tank in LS DYNA.
I study the delamination of laminates upper and bottom skins of honeycomb composite structure simple supported from two sides and under bending stress.
I consider the developed tension on the bottom skin as the main peeling force that cause delamination.
Is my thinking correct?
Also, do you suggest textbooks?
I'm looking to culture human oral fibroblasts to test cytotoxicity of composite resin.
So far I've had no luck in isolating fibroblasts from a 2mm of excised gingiva.
Can anyone share techniques to improve isolation?
We conducted the tensile test of the CFRP.
So, we want to observe the fractured surface of the CFRP using 250x microscope.
Can we observe sufficiently the fiber and resin in that surface using 250x microscope?
I need to perform tensile testing on samples of glass fiber - epoxy resin composites. the fiber is chopped ( discontinuous ) and randomly distributed.
I found different information about which standard to follow, some sources recommend ATSM D3039 which has a sample thickness of 1mm and other sources recommend using ATSM D638 ( because my fibers are discontinuous ) which has range of specimen dimensions.
Which standard should i follow ? more specifically what is the recommended thickness for my case ?
Matrix degrade early due to UV, moisture etc. Please suggest the possible methods to prevent such degradation.
I am wondering the critical resin properties such as viscosity which are important during manufacturing of towpreg, prepreg and slit tape based on epoxy and glass or carbon fabrics. Thank you.
I am working on the enhancement of mechanical properties of resol. Sometimes we add alkylating agents during synthesis of resoles. My question is why we add alkylating agents? Do they affect mechanical properties of resinand what is the best controlled composition of this resin?
What are the Parameters to be considered, While Sonication ?? What are the amplitude, frequency and timing need to be maintained?
I would like to know what are some viscosity values during filling stage of RTM procedure as also during the curing procedure.
I have been looking for sometime without success on the web and in the literature for a curable polymer with an intermediate Youngs Modulus range:3MPa-500MPa.
Could anyone give me some suggestion on this?
Our team is using FEI Quanta 450 FEG for SEM analysis for the first time. We are testing materials like membrances and carbon fibre brush carrying microorganisms. Can you help us with pre-treat methods, materials and techiques to prepare such materials (mentioned above) in order to enhance our analysis?
this is the SEM image of a cement sample, I cannot see any variation in the phases such as C3S, C2S, C3A, C4AF. I did not use EPOTEK 301 as it is expensive and used araldite (epoxy and resign). should I change the resin to a low viscus to get results.
your feedback is important to me.
The samples will be used for tensile testing directly after spinning. I'm trying to avoid damaging my sample and do not want to use the SEM to measure the thickness. Any suggestions will be greatly appreciated. FYI, the fibers are spun on two stationary plates. The mats are extremely thin.
Is it possible to reach the maximum Tg of an epoxy resin with postcuring ? For example, if I would cure an epoxy resin at room temperature and postcure it with active heating until no conversion can be detect anymore. Does it reach the same Tg as an epoxy resin which is freshly mixed and immediately cured by active heating ?
Curing in thermostats is achieved through variety of methods , for example, heating or radiation. I am interested to know level (% or fraction) of curing in samples cured through two different techniques.
I need information or article about body bus manufactured with fiber glass reinforced polymer and rollover test requested by UNECE R 66.
Good day to all. I need advice on preparing nano zirconia in polymer. After inside the zirconium precursor with acetone,water and acid, I cast my mixture but then in few day I notice that white solid layer on the bottom. I think my zirconia not mix with my polymer. If i prepare silica as the filler with the same procedure, the end dried sample is completely homogenize. Kindly need advice on this matter.Your attention and comments are highly appreciated.
My working in a fiber plant. we use DMAc for solvent
I last week, we have a fire is system spinning. Now, i am trying to find some standard operation to prevent the fire in next time.
- The polymer, have 65% DMAc, is dried by hot air at 270 degree celsius - open system.
I will calculate the concentration of DMAc in the air ( volume ~ 1.3m3) and the volume hot air is used. After that, comparing it with the temperature. It's is possible ?
I want to find some document or reference about this problem. I hope someone can help me.
Thanks you very much.
In general, which type of resin has the greater exothermic energy during the curing process in the same environmental conditions?
Thanks for your reply
To bond polyacetal (POM), firstly, I used chromic acid to prepare the surface of polyacetal and then tried some adhesives like cyanoacrylate, epoxy, PVC, and polychloroprene (Pattex, Henckel) adhesives but none of them showed good bonding. Could any body help me to find a suitable adhesive formulation and may be procedure for polyacetal bonding?
The nature and type of adhesive used in manufacture of composites depend on the end use of the composites.We plan to use urea formaldehyde resins for our wastepaper based composites.Any alternative or suggestions.
I am working on a high modulus adhesive. I am preparing dog-bone samples for tensile tests, I've tried to vacuum the adhesive in different ways like several short periods and each time skimmed it and vacuumed again, another way I vacuumed samples in a long period and cured them Simultaneously, but I can't eliminate voids and have a prefect sample.So, If you can offer me some tips to increase the quality of my samples
Hello, I need the best industrial process for production of urea-formaldehyde resin with molar ratio of 1.1 suitable for MDF and particleboard production with continuous hot press and prepress. With special thanks
how can i removed bubbles formed during mixing epoxy resign & hardner i am using Araldite AW106 and hardner HV953. How to degas the mixture?
Does someone have experience of cleaning cured phenolic resin? Is there some stripping agent available? Thanks!
I need to formulate Ni-current collector for screen-printing application. In this formulation binder must be compatible with positive material (resist to a potential of 4V in presence of electrolyte). Any idea of the resin/solvent that I can use as a binder? thank you in advance
What additive to bismaleimide resins could most effectively improve the impact strength of the entire composition ???
I tried making composite out of Araldite CY-230 epoxy and HY-951 hardener. But it is remaining in gel form and not solidifying. What may be the possible reason?
I am trying to determine the constituents of the wax-based coating of a paper bag for my study. I have contacted the manufacturer who will only give me "some" components which were: Emulsion Acrylic Co-polymer, Melamine Resin, Petroleum Resin, and Paraffin Wax.
But a brand new bag has a strong odour, indicating the use of VOCs.
Does anyone have any idea then what would be the standard chemicals used to make such a coating to be applied to a paper bag? And if so, any idea on the % quantities?
A shot in the dark, hopefully someone has some kind of info.
How can I built up a test plan for process qualification for a composite manufacturer.
Can someone could provide me with a traveler specimen test plan?
Recently I am fabricating PEEK composite films, so I try to cast pure PEEK film firstly.
I bought PEEK pellets. I try to dissolve PEEK in DMAC, but it can’t be dissolved. I once succeed dissolving PVDF and PMMA in DMAC, and cast to films. But it doesn't work for PEEK.
I have searched from the internet, someone said the only solvent that may be able to dissolve PEEK is concentrated sulfuric acid through a sulfonation reaction. My target is to prepare the PEEK films, it’s difficult and dangerous to volatilize the solvent. Is any safe and easy method to dissolve PEEK pellets and fabricate films?
Any suggestion will be appreciated.