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I premise, I’m a physicist and I’m working on a transfer procedure for graphene via CVD, which involves the use of PMMA as a resist layer. Studying this polymer, I still haven’t found what is the cross-link temperature (or window of temperatures) for it. Can someone give me a hand? or just a good reference?

UPDATE Ok, maybe I’ve been misunderstood. My PMMA is diluted in anisole, and I apply it as a photoresist over the graphene sheet via spin coating. After this deposition NO Initiator is used, but it came across various heat treatment, depending in the recipe I use. My question is: does anybody know at what temperature the PMMA starts to seriously crosslink? or better: if I do more heat treatments, all at temperatures above 150 °C, am I going to have an highly crosslinked PMMA, so that a removal process in acetone solvent is impossible because it can’t get into the chains to districate them?

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According to this thesis, the polymerization is determined by thermal initiator that is used in PMMA mixture. The polymerization (corsslinking) starts when the initator is added to the mixture, but it is really slow at low temperature. Higher temperature lowers hardening time (speeds up the crosslinking). Since the dustsheet does not provide the information about the initiator, I would suggest to determine the cross-linking temperature experimentally. Some material related to the polymerization process:http://www.chemistry2011.org/,

BULK POLYMERIZATION OF METHYL METHACRYLATE IN A KNEADER REACTOR P.-A. Fleury LIST AG CH-4422 Arisdorf,

High conversion polymerization of methyl methacrylate in the presence of poly(methyl methacrylate) of different relative molecular mass J. BARTOŇ, V. PASTUŠÁKOVÁ, V. VAŠKOVÁ, and P. AMBROVIČ Polymer Institute, Centre of Chemical Research, ChemicalPapers

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  • $\begingroup$ It would be quite terrific if you would include the complete citations, especially when they are not linked to the DOI. Sometimes one can find such papers on mirrors on the internet, but in order to prevent this answer from link rod, it is better to name the sources directly. $\endgroup$ – Martin - マーチン♦ May 27 '15 at 11:45
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Ok so i got the answer to my question. For what i've understood, PMMA, as it is a thermoplastic polymer, is unable to crosslink unless it's "mixed" with an initiator. The removal process is going to be difficult if temperatures are going to get over 150°C due to the degradation of the polymer in species that may not be diluted in organic solvents

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