THE ANALYSIS OF MICRO- AND MACRO-MECHANICAL DEFORMATION IN POLYMETHYLMETHACRYLATE AS A MODEL MATERIAL SYSTEM FOR DIMETHACRYLATE SEALANTS

Natasha Case, Dr. B. J. Love and Virginie Vaubert
National Science Foundation and Technology Center:
High Performance Polymeric Adhesive and Composites, and
Department of Materials Science and Engineering
Virginia Polytechnic Institute and State University
Blacksburg, Virginia

ABSTRACT

Polymethylmethacrylate (PMMA) was used as a model material system for the development of a testing scheme to analyze the mechanical properties and deformation mechanisms induced under tensile loading in dimethacrylate dental sealant material. The tensile properties of 75K and 100K molecular weight PMMA samples were measured. The 75K hole samples showed a decrease in mechanical strength when compared to the 75K pristine samples. The 100K material showed no real difference in strength between the pristine and hole samples. The 100K material exhibited a lower fracture strength than the 75K material. The presence of a glow agent in the 100K material most likely resulted in the lower strength observed. Tensile deformation mechanisms were characterized in PMMA and polycarbonate (PC). Multiple types of deformations were located in PC specimens, while only one kind of deformation was found in PMMA specimens.