Abstract
Purpose: The purpose of this study is to develop a new method for microwave resin polymerization in which the polymerization temperature is controlled by direct and accurate measurement of the temperature and subsequent feedback to the microwave source.
Methods: In this newly developed resin polymerization method (feedback polymerization method), the microwave output is controlled by feedback of the measured temperature during polymerization. A fluorescence fiber thermometer is used as the sensor. To evaluate the proposed method, we compared feedback polymerization for 3 min at 500 W with thermal polymerization for 40 min at 60°C and 100°C, and low-temperature long-duration polymerization for 24 h at 70°C. The resulting polymer samples were then evaluated in terms of their conformance and other properties.
Results: Accuracy results of the adaptation test, the three-point bending test, and the Vickers hardness test were comparable or better for the feedback polymerization method than for other methods tested. On the other hand, the feedback polymerization method showed the second-inferior results after the low-temperature long-duration polymerization method in both the residual monomer test and the cytotoxicity test.
Conclusions: It was clarified that the feedback polymerization method was highly suitable for producing polymers with good adaptation and other mechanical properties, and except for a few results, it was comparable or superior to other polymerization methods.
