Embedding small precious objects in methyl methacrylate polymer - in cavities filled with polymer dissolved in monomer and then polymerised

摘要

Methacrylate block has cavities made in it to the approximate size and shape of the inorganic objects to be embedded. It is then heated, to eliminated tensions from the worked surfaces, and to dry it. After fine sanding, the cavities, with the objects in place, are filled completely with a soln. of methyl methacrylate polymer in its monomer, to which a catalyst or accelerator has been added to facilitate polymerisation. The viscosity of the soln. is carefully controlled to limit contraction. For the same reason, polymerisation at 20 degrees C is over =3 hrs.