Polymer Chemists' Network

• Kolli bala krishna

  In GPC analysis, what are parameters in X and Y axis of the graph!

  Polymer analysis

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  • 
    Mohanad Mousa Kareem replied

    As I know the axis Y represent the intensity and the axis X represent the time.

    1 hour ago
• Mrembo Early

  Solution casting

  Does anyone have infomation, suggestions or has come across any detailed articles on this topic...I need to understand the procedure and parameters for solution casting of polymer membranes fromDoes anyone have infomation, suggestions or has come across any detailed articles on this topic...I need to understand the procedure and parameters for solution casting of polymer membranes from 25-150 micrometers...
• Rehan Ali

  Which polymer (powder) is most soluble in water?

  Also it should not harden after sometime , it should remain semi-liquid for a long time.

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  • 
    Hatem Majdoub replied

    I Think, it's pollyethyleneglycol if you need synthetic and non-ionic polymer.

    2 days ago
• Xuemei Kang

  How to measure the strain applied on polymer?

  I make polymer coating on the elastic substrate, and twist the surface of the coating to observe the allochromasia processing and then measure the precise pressure or stain applied on the polymerI make polymer coating on the elastic substrate, and twist the surface of the coating to observe the allochromasia processing and then measure the precise pressure or stain applied on the polymer coating that trigger the color transferring. There are two problems: 1. If I twist directly on the coating surface, the coating polymer is easy to fall off 2. I put a piece of glass sheet over the coating, and twist on the glass. If I apply this method, how to measure the strain by the twist?

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  • 
    Oznur Kaftan replied

    @ Mr. Cruz. The approach you suggested (first measuring the blank material, then subtracting or comparing with the result after the addition of analayte or material of interest) is valid for almost@ Mr. Cruz. The approach you suggested (first measuring the blank material, then subtracting or comparing with the result after the addition of analayte or material of interest) is valid for almost all scientific measurements if blank and analayte are in the same range... In this case I just want to draw your attention that the contribution of polymer film can be negligible because it is very thin comparing the substrate.... I may explain it in a different way. Imagine that you want to measure the breaking force of a piece of paper and you use an Iron or a Steel stick as a blank. First you measure the breaking force of Steel stick and then cover it with paper and measure the breaking force again. The force measured in later case wouldn't be different (or will not be detectable) than the first measurement. The contribution of paper in the total measured breaking force would be so small, and can not be compared in this way. I hope now it is more clear now.

    4 days ago
• Alfred Leung

  Does anyone know why polydispersity of nanoparticles are less then 1? For polymers PDI are always greater then 1?

  Does anyone know why polydispersity of nanoparticles are less then 1? For polymers PDI are always greater then 1?

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  • 
    Manmatha Mahato replied

    As nano particle has high surface energy due to very high surface area, they face strong interaction between them and agglomeration occurs/ that's why PDI decreases significantly.

    5 days ago
• Heba Hassan

  How can I use polyaniline film as electrode for gas measurements?

  What is the set up needed for this measurements

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  • 
    Manmatha Mahato replied

    It is better to use four probe metal contact rather than two probe or vander pow method.

    5 days ago
• Rameshwor Lamichhane

  How to make augmented cartridge from nitrocellulose?

  I wish to make augmented horseshoe cartridge from nitrocellulose. What is the best easily available plasticizer instead of camphor? Suggestions with procedure are highly appreciated.

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  • 
    John Spevacek replied

    There is published research using nitroglycerine, triacetin, diethylene glycol dinitrate and dimethylacetamide as plasticizers of nitrocellulose.There is published research using nitroglycerine, triacetin, diethylene glycol dinitrate and dimethylacetamide as plasticizers of nitrocellulose. http://www.sciencedirect.com/science/article/pii/0032386188901553

    27 days ago
• Hari Haran

  ceiling temperature Vs degradation temperature?

  What is the relation between ceiling temperature and degradation temperature?

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  • 
    James E Hanson replied

    Temperature of decomposition (Td) and ceiling temperature (Tc) both have to do with the thermal stability of polymers. At Tc, rate of polymerization and depolymerization are equal - so below TcTemperature of decomposition (Td) and ceiling temperature (Tc) both have to do with the thermal stability of polymers. At Tc, rate of polymerization and depolymerization are equal - so below Tc polymer is thermodynamically stable, while above Tc the polymer is thermodynamically unstable. This does not mean that polymer cannot exist above Tc - certain poly(olefin sulfones) used as electron beam resists take advantage of this. The polymer is prepared at low temperatures (-77 C). Room temperature is above Tc, but depolymerization requires a chain scission to begin - thermally this does not happen until 200 - 300 C (that would be the Td). But if a chain break is created by electron beam radiation, the chain rapidly depolymerizes to the highly volatile monomers (for example, 1-butene and SO2). Td is more commonly used - in TGA it is the temperature at which decomposition starts. There is some dependence on rate of heating. Most organic polymers decompose between 200 and 300 C, but a few are stable up to 500 C.

    28 days ago
• Vijay Kumar

  Deposition of polyaniline thin films.

  Can any one suggest a substrate for spin coating/drop casting/dip coating method to deposit polyaniline thin film in which adhesivity should be better? Does glass substrate work better or should ICan any one suggest a substrate for spin coating/drop casting/dip coating method to deposit polyaniline thin film in which adhesivity should be better? Does glass substrate work better or should I try in some other?

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  • 
    S VINODH KUMAR replied

    Quartz will be better for spectroscopical characterization.

    Apr 20, 2012
• Mohamed EL HASNAOUI

  "Intrinsic hopping effect" in composite materials.

  I would like to know what "hopping effect" means and how it can be determined.

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  • 
    Mohamed EL HASNAOUI replied

    Dear Gyory - Yes you are right, The melting tempertrure corresponds the endothermal peak, it is near the inflection points( it was a mistake). The glass transition temperature of this composites wasDear Gyory - Yes you are right, The melting tempertrure corresponds the endothermal peak, it is near the inflection points( it was a mistake). The glass transition temperature of this composites was found in others works equal -75 °C. I am interested in EAB copolymer because the subjet of my preparation of doctoral degree ( I interested by transport preoprietes not mecanical). - I am interested by other question that I received for correction other article, it is ( what evedence of cristallinity of epoxy DGEBF loaded BC particles, like X-ray , DSC, ....), I would like an article that used X-ray to show the critalilinity of epoxy-resin. this is my mail: med_elhasnaoui@yahoo.fr Thank you Sir for your interested

    Apr 10, 2012
• Mohd Arif Agam

  Zwitterion Characteristics and molecular structure of polymer alteration due to overexposure of radiation (Electron beam or Laser)

  In our research, we found out that polystyrene will operate better in Reactive Ion Etching after over exposure of Electron Beam or Laser Irradiation. Polystyrene seems to change its chemicalIn our research, we found out that polystyrene will operate better in Reactive Ion Etching after over exposure of Electron Beam or Laser Irradiation. Polystyrene seems to change its chemical structure and we are puzzled, which part of the molecular structure interacts with the irradiation source? How do we control the the effect, so that we might understand when the polymer such as polystyrene starts to change it chemical structure, thus change from negative resistance to positive resistance.

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  • 
    Mohd Arif Agam replied

    TQ guys. I did on 500 nm polystyrene nanospheres. I know the polymer can crosslink, but as we know negative resist could let the molecular of the polymer been cut into small pieces and can beTQ guys. I did on 500 nm polystyrene nanospheres. I know the polymer can crosslink, but as we know negative resist could let the molecular of the polymer been cut into small pieces and can be dissolved with organic solvent, but when you overexposure either laser or electron beam to the polymer, the polymer will change from negative to positive resist...which could be interpret as more binding or crosslinking taking place, thus creating more dense carbonaceous materials, which later become more resistant toward reactive ion etching or organic solvent. I would like to have comment from Chemist people...any comment.

    Mar 27, 2012
• Vijay Kumar

  How can I prepare polyaniline thin film using chemical route?

  I have tried a lot to make polyaniline free standing sheet using chemical route but it is quite brittle and non uniform. How can I overcome these issues?

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  • 
    Daniel Horacio replied

    Another way is making nonwoven with nanofibers, you can assembling extremely thin layers of PAni through eletrospinning process. Generally you can use THF as solvent for PAni, then, let thisAnother way is making nonwoven with nanofibers, you can assembling extremely thin layers of PAni through eletrospinning process. Generally you can use THF as solvent for PAni, then, let this solution in a ultra sound bath alternating with stirring procedures.

    Mar 26, 2012
• Ilangeswaran Dha

  What are the N-N stretching and bending vibrational frequencies in IR spectrum of hydrazine?

  To give ir interpretation

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  • 
    Gyorgy Banhegyi replied

    Sorry, but why do you not useSorry, but why do you not use Google? http://jcp.aip.org/resource/1/jcpsa6/v20/i1/p136_s1?isAuthorized=no http://www.sciencedirect.com/science/article/pii/S0022285203001061 http://www.kintecus.com/Kin_05-OLF-CEJC-Dirtu.pdf

    Mar 25, 2012
• Kinjal Shah

  Which are the polymers are use for making thermal conductive composites?

  Polymers use for making the bodies of the machines and it must be having good thermal conductivities./

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  • 
    Gyorgy Banhegyi replied

    Most frequently polymers are rendered heat conducting by adding high heat conductivity ceramics (e.g. BN, AlN, alumina, ZnO), or by addig metals, or other electrically conducting additives as carbonMost frequently polymers are rendered heat conducting by adding high heat conductivity ceramics (e.g. BN, AlN, alumina, ZnO), or by addig metals, or other electrically conducting additives as carbon black, carbon fiber, carbon nanotube, graphene etc. The question is, whether you need electrically insulating heat conductive compounds - in this case you need to use ceramics, or electrically conductive ones - in this case you may use carbon or metals. Polymer heat conductivites are in the order of 0,1-0,2 W/mK, which can be increased at best to 5-10 (these are very high values at high filler loading). Highly filled polymers cannot be processed easily. You can buy high heat conductivity thermosets (epoxies) or rubbers (e.g. silicone rubbers).

    Mar 25, 2012
• Dariuosh Ebrahimi

  The industrial production of Divinylbenzene, how?

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  • 
    Ralf Kollefrath replied

    Here it can beHere it can be downloaded: http://worldwide.espacenet.com/searchResults;jsessionid=36872B88E4A921033AB761DD2DF6F9F0.espacenet_levelx_prod_5?DB=EPODOC&locale=de_EP&ST=advanced&compact=false&PN=US3375289

    Feb 23, 2012