PMMA is obtained by free radical polymerisation of MMA. This polymerisation can be completed at RT condition by the addition of initiators. When the poilymerisation mass is solid and reaches a Tg higher than the temperature of the solid polymer the polymerisation reactions stop. In the solid polymer remains trapped some unreacted MMA in quantity ranging between 20 and 25%. The presence of the monomer reduces, besides, the tensile strength of the polymeric mass that after RT polymerisation ranges between 35 to 45 MPa. One way to increase the strength of it is to apply a Thermal treatment. I am looking for a way to double the tensile strenght without post curing.
Thanks
If the PMMA is transparent to UV light, you may try to create radicals on the MMA to keep the polymerization process going without the use of heat....
Dear Luca
One way of increasing the tensite strength of a polymer is by adding fiber/flakes of carbon or aluminum to the polymer, in order to have a fiber reinforced- polymer.
PMMA can be purified from its monomer by dissolving the polymer in a solvent and then adding an excess of a non-solvent to precipitate the polymer out.
This suggestion requires trying: PMMA is dissolved in a proper volume of toluene until the solution is clear. Three times of that volume of methanol is added with stirring until PMMA precipitates & accumulates on the thick glass rod. The mixture is then filtered. My "expectation" is that the trapped MMA monomer will go into the filtrate.
Once there is pure PMMA, physical properties, such as tensile strength, could be studied well.
Some, more wild ideas to get more free radicals formed in MMA would be to shock load the MMA (high velocity impact or detonation of an explosive inside it) or use (gamma) radiation to break up some chemical bonds.....
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