IADR Abstract Archives
Effect of Boron Nitride Nanosheets on OASys Composite Properties
Objectives: An antimicrobial, superhydrophobic Oxirane/Acrylate Interpenetrating Network Resin System (OASys) composite using a multifunctional oxirane (Epalloy 8370), a multifunctional acrylate (dipenta erythritol hexaacrylate), a difunctional methacrylate (urethane dimethacrylate) and a hydrophobic fluorinated acrylate (2-perfluorooctylethylacrylate; PFOEA) was developed. This composite cured well, had contact angles >110°, and had significantly reduced volumetric shrinkage (~50% reduction), shrinkage stress (~80% reduction) and wear rates in extremely caustic conditions (~50% reduction in pH 2.7) than control BisGMA:TEGDMA composites. However, this composite is very viscous and opaque and had lower mechanical properties. Thus, the objective is to determine the effects of adding Boron Nitride Nanosheets(BNNs) on OASys physical and mechanical properties. The hypothesis is that hydrophobic oxirane-functionalized BNN’s would decrease the need for PFOEA to form a hydrophobic composite and disrupt the phase separation between the PFOEA and oxirane components and increase composite translucency and mechanical properties.
Methods: OASys composites were loaded with 0.5% w/w BNN and its effect on decreasing PFOEA concentration, composite degree of cure (Rockwell15Thardness), hydrophobicity (contact angles measurements), translucency and mechanical properties (3-point bend test) were determined.
Results: Addition of BNN did not affect composite hardness indicating that all composites cured well. It also allowed the reduction of PFOEA concentration to 20% w/w with no reduction in contact angle. Composites with BNN and 17% w/w PFOEA still produced hydrophobic composites, but the contact angle was reduced to 92°. With 17% w/w PFOEA, translucency increased an order of magnitude, modulus significantly increased from ~4.4 GPa to ~5.5 GPa, ultimate transverse strength significantly increased from ~61MPa to ~67 MPa and energy to break increased significantly from ~11 MPa to ~13 MPa.
Conclusions: Small amounts of BNN significantly reduced the PFOEA concentration needed to produce hydrophobic composites, and that, in turn, significantly increased composite translucency and mechanical properties.
Methods: OASys composites were loaded with 0.5% w/w BNN and its effect on decreasing PFOEA concentration, composite degree of cure (Rockwell15Thardness), hydrophobicity (contact angles measurements), translucency and mechanical properties (3-point bend test) were determined.
Results: Addition of BNN did not affect composite hardness indicating that all composites cured well. It also allowed the reduction of PFOEA concentration to 20% w/w with no reduction in contact angle. Composites with BNN and 17% w/w PFOEA still produced hydrophobic composites, but the contact angle was reduced to 92°. With 17% w/w PFOEA, translucency increased an order of magnitude, modulus significantly increased from ~4.4 GPa to ~5.5 GPa, ultimate transverse strength significantly increased from ~61MPa to ~67 MPa and energy to break increased significantly from ~11 MPa to ~13 MPa.
Conclusions: Small amounts of BNN significantly reduced the PFOEA concentration needed to produce hydrophobic composites, and that, in turn, significantly increased composite translucency and mechanical properties.