Heterocyclic methacrylates for clinical applications. III. Water absorption characteristics.

The water absorption and desorption behaviour of poly(isobornyl methacrylate) and poly(tetrahydropyran-2-ylmethyl methacrylate) obeyed diffusion laws on repeated absorption/desorption cycles. However, the polymers of 2,3-epoxypropyl, tetrahydrofurfuryl and tetrahydropyranyl methacrylates did not obey diffusion laws, did not equilibrate after 2 yr immersion in water and exhibited very high uptake values (30-90%). For 2,3-epoxypropyl methacrylate, the sample disintegrated. A clearly detailed structure of the heterocyclic ring is critical. The use of these monomers in room temperature polymerizing poly(ethyl methacrylate)/monomer systems generally reflected the behaviour of the related homopolymers.