N Silikas1, D C Watts. 1. University of Manchester Dental School, UK. n.silikas@stud.man.ac.uk
Abstract
OBJECTIVE: The purpose of this study was to measure the viscosity of resin formulations and investigate the relationship between diluent percentage and temperature. METHODS: Resin formulations were prepared using UDMA and either TEGDMA or HEMA, or HPMA, as diluents at different percentages. Viscosities were obtained with a Bohlin Rheometer at 23 degrees C for all formulations, and at 37 and 60 degrees C for selected formulations. RESULTS: The viscosity of the formulations exhibited Newtonian behaviour and decreased as the percentage of the diluent monomer increased, especially up to 40% of diluent. Linear regressions relating log(viscosity) and mass percent diluent, were obtained in the range 20-80% diluent. Viscosity also decreased as the temperature increased. Activation energies were calculated from Arrhenius plots, and ranged from 16.2-23.4 kJ mol-1. SIGNIFICANCE: The viscosity of the resins controls the flow properties and thus has a significant effect on the deployment of the respective monomers.
OBJECTIVE: The purpose of this study was to measure the viscosity of resin formulations and investigate the relationship between diluent percentage and temperature. METHODS: Resin formulations were prepared using UDMA and either TEGDMA or HEMA, or HPMA, as diluents at different percentages. Viscosities were obtained with a Bohlin Rheometer at 23 degrees C for all formulations, and at 37 and 60 degrees C for selected formulations. RESULTS: The viscosity of the formulations exhibited Newtonian behaviour and decreased as the percentage of the diluent monomer increased, especially up to 40% of diluent. Linear regressions relating log(viscosity) and mass percent diluent, were obtained in the range 20-80% diluent. Viscosity also decreased as the temperature increased. Activation energies were calculated from Arrhenius plots, and ranged from 16.2-23.4 kJ mol-1. SIGNIFICANCE: The viscosity of the resins controls the flow properties and thus has a significant effect on the deployment of the respective monomers.
Authors: Sri Vikram Palagummi; Taeseung Hong; Zhengzhi Wang; Chang Kwon Moon; Martin Y M Chiang Journal: Dent Mater Date: 2019-12-19 Impact factor: 5.304
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