How can I prepare Polyvinyl alcohol (solvent- Water) coating? Is there any cross linked agent for Polyvinyl alcohol compounding? How to dissolve Polyvinyl alcohol 100% hydrolyze in water?
Mr.Kumareswaran Subasgar,
Mix desired concentration of PVA and water in an air tight container and heat it in water bath till 80°C for approx. 30min till you attain a clear homogenous solution. This polymer solution can be used for coating purpose.
With regards,
Arun Bhupathi
Take PVA powder in cleaned resist bottle and capped properly. Heat the water up to 90 °C, where it works well. Measure water and add in bottle and close it properly again. Allow mixture to sit until polymer is fully solvated. Place solution in the solvent bench to suitable thickness. Bake sample at 90°C on hotplate to drive off water. Clean any residue with isopropanol.
Mr.Kumareswaran Subasgar,
Mix desired concentration of PVA and water in an air tight container and heat it in water bath till 80°C for approx. 30min till you attain a clear homogenous solution. This polymer solution can be used for coating purpose.
With regards,
Arun Bhupathi
Couldn't get a thin homogeneous film with only PVA and water. Is there any cross linked agent for PVA compounding?
Hi,
If I understand correctly, you might have following scenarios,
Hope this helps,
Mayur.
Hi, Mayur Kumbhani, Could you please explain, how to do cross linking with Sodium borate? Is there procedure?
Already I tried with TEOS+EtOH+H2O+HCl & BOPP. But couldn't get proper result please help me. I want to laminate rubber glove with PVA for chemical resistant purpose.
If poly(vinyl alcohol) is not available in your laboratory, then you have to prepare it by the hydrolysis of poly(vinyl acetate) & the procedure is available in many references. If it is available, then look first on its average molecular mass before you proceed. A lower molecular mass polymer is easier to work with. Usually, PVA is treated with butanal & this aldehyde causes intra- crosslinking to produce what is commercially known as "Butvar" a laminate used to adhere the front double sheets of glass windows of cars, buses...etc. This reaction could be used for film forming as well when the solvent is left to evaporate completely.
Does the Sodium Borate work well as a crosslinked agent with PVA solution? did u get a thinner and homogeneous film? What's the substrate that you wanted to coat?
Please let me know, Thanks
PVA is a synthetic, odourless and colourless polymer that is prefered for coating applications. It can dissolve in water at 80-90°C. If you want to coat hydrophilic or water soluble surface, you apply the PVA solution directly. But if you use a polymer surface that is a unsoluble water. At this point, you have to use a crosslink agent like Glutaraldehyde or TiO2 etc. Be careful the crosslink agent concentration because the more concentration can decrease the barrier effect. after you prepare the PVA solution that contains crosslink agent, you arrange the surface energy between the coating surface and your solution. water has 72 dyne/cm surface energy. So, lots of water unsoluble polymer has 34-56 dyne/cm. therefore you must decrease the surface energy of your PVA solution via using ethylalcohol etc. 80 water: 20 Ethanol solution has 38 dyne /cm. It is a suitable surface energy for PE, PP, PET, PA. Thats all.
Deniz Kopan Hi, I have seen your answer it was definitely useful for my current final year project, What I wadnt to ask is when applying PVA to a plastic surface like Polypropylene, do I need to use crosslink agent as well or can I just straightaway apply it. I cant find an solutions from Google and would love to get help from you. Thank you
Hi, could you please explain how I can prepare coating agent for PVA fibers?
You have to use aldehydes as butanal which is a crosslinked agent !
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