Improvement in the properties of gypsum casts by polymer impregnation

It is known that porous solids such as Portland cement, concrete, and ceramic tile bodies can be strengthened by polymer impregnation. The solid material is infiltrated with a liquid monomer, which is then polymerized in situ. In the present investigation, it has been found that this process is effective for strengthening gypsum casts prepared from ordinary laboratory plaster. Impregnation with poly(methyl methacrylate) confers marked improvements in tensile and compressive strength and abrasion resistance. The process would be particularly applicable to the preservation of study casts for record purposes.