pmma comparison samples prevents diffusion of glycerin into the surface 5 6 of the pmma workpiece 1 this is the second experimental evidence of the inventive waterproofing of the polymer surface 5 of a polymer workpiece 1 in a third exemplary embodiment of the invention the inventive waterproofing of a pmma polymer workpiece 1 was tested for protection against water vapors for this purpose an untreated pmma workpiece 1 r u00f6hm gs plexiglas was first divided into four samples these pmma samples were then weighed on a balance having an accuracy of u00b1 0 1 mg the average weight of the four samples was determined to be approximately 0 7 g one of the pmma samples was subsequently used as the untreated pmma reference sample the other three pmma samples were subsequently used as pmma comparison samples and for this purpose were treated in an inventive dipping bath 2 according to fig1 for 20 minutes at room temperature the first pmma comparison sample was treated according to the invention in toluene with a tpsf concentration of 12 by weight the second pmma comparison sample in toluene with a tpsf concentration of 23 by weight and the third pmma comparison sample in butyl acetate with a tpsf concentration of 32 by weight thereafter the three pmma comparison samples were removed from dipping bath 2 and air dried at room temperature subsequently the second and third pmma.