Hi,
I'm aware that thin film of PMMA can be spin coated. But I'm more interested in making few mm thick PMMA which will act as a substrate. Please share your expertise on how this can be achieved.
Thank you!
Dear all, it is a sheet and not a film. You Can use extrusion, injection or compression moldings. What is the length and the width ? My Regards
Dear all, it is a sheet and not a film. You Can use extrusion, injection or compression moldings. What is the length and the width ? My Regards
@Md.Akibul Islam,
You can make a glass chamber. Ideally use MMA and initiator to make solution. Then fill into homemade a glass chamber. Put into an oven for thermal conversion of PMMA slabs. The chamber can be made of two pieces of microscope slides and sealants on the surrounding. Once PMMA is formed, you can take the sealant off, so nice transparent PMMA slabs are obtained. In principle, you can make any thickness you like. I did it 3 or 5mm thickness easily. You can make color ones if you like by doping some colouring dyes.
Hi;
You can use compression molding at 200-220°C and 170-180 MPa pressure.
With my best regards
Thank you everyone for your kind responses. I really appreciate it!
Thin film of upto 100 nm thick with PMMA film is ok but to make in mm size 3-5 mm .PMMA of Mol weight more than 120000 to take for more strength ,colloidal stabilty as fibrebased nanocomposites ,with more to have -ve charge with etherification or esterification of hydroxyl groups of PMAA .More OH negetive charge may give big size fibre in negetively charged suspension or adding through oxidation oxygen or perscetic acid .
Rightly pointed out above; it is not film but a sheet. This can be easily and conveniently prepared by bulk polymerization technique carried out in molds made out of glass sheets; filled with the monomer along with initiator, closed and suspended in heated water baths, maintained at desired constant temperature, while simultaneously shaking the mold using appropriate shaking arrangement. Basically it amounts to reducing one of the dimensions (thickness) to facilitate heat transfer.
no the best way to prepare PMMA sheets without any voids is to use prepolymer syrup. First take MMA monomer and initiator and carry out bulk polymerization ,arrest the polymerization by quench cooling when you reach 25-30% conversion.
After cooling prepare a mold by taking two toughened glass sheets and rubber gasket of required thickness[you need in sheet] and hold the two glass sheets with spacer using clamps. Keep the one side of mold open. Prepolymer syrup prepared should be mixed with a fresh dose of initiator and degassed to remove the trapped air. After degassing, fill this syrup into a mold and close the side with rubber gasket and also clamp this side also.
Filled mold should be heated in water bath at 80 C [if BPO is used as initiator] for four to five hours and then postcured in oven at higher temperature. You need to use mold release agent also so that the sheets can be removed easily. After postcuring open the mold and take out sheets.
Hallo Akibul, do you want to coat a film or really start from the monomer?
In my previous work I dissolved PMMA (granules/powder) in Toluene or THF. We used knife coating (or also called doctor blading) for films in the µm range. You could use an applicator (we used the ones of the company "Zehntner" which is now Proceq; Switzerland) with a gap width of several mm to give it a try or try to coat several layers on top of each other. If cracks in your films occur you should dry at very moderate conditions.
Regards,
Sebastian
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