This work aims to produce and disseminate videos that follow the microlearning methodology, to explain the physicochemical properties of cobalt (II) chloride hexahydrate through thermal analysis, and to determine the reliability of the Portuguese good luck rooster. Temporal and social accelerations due to the growth of the technological world are changing the old teaching-learning methodologies; thus, new methods should be explored. In the microlearning methodology, short segments and specific content can be broadcast to anyone at any time. In addition, relating new information to individual’s experiences can favor the teaching-learning process. The good luck rooster is an ornament of Portuguese origin, which can forecast the weather in a limited way, and is composed of cobalt (II) chloride hexahydrate. This compound was characterized by TG-DTA (Simultaneous Thermogravimetry-Differential Thermal Analysis) and DSC (Differential Scanning Calorimetry), verifying that the salt loses its hydration water when exposed to high temperatures, changing its color from pink color to blue.

Abstract This paper evaluated the influence of the incorporation of the coinitiator Ethyl 4-(dimethylamino) benzoate (EDB) in Filtek Z250 XT resin in the reduction of the polymerization time and its behavior in halogen light and LED (Light Emitting Diode) light. The samples were subjected to thermal and spectroscopic analysis. The TG/DTG-DTA curve showed that both samples studied have a thermal stability temperature similar to the other polymers in the monomer blend. Morphological features were analyzed by SEM. By the MIR analysis, the degree of conversion using halogen light showed a better result compared to the LED light. The polymerization time applied to the specimens was 10 seconds, reducing the original resin time by half.

The aim of this paper is to replace toxic coinitiators (tertiary amines) by non-toxic compounds such as glycerol and inositol (polyalcohol) in dimethacrylate resins. For this purpose, mid infrared spectroscopy (MIR) was used to calculate the monomers' degree of conversion (%DC); as well as simultaneous Thermogravimetric Analysis – Differential Thermal Analysis (TGA-DTA) and Differential Scanning Calorimetry (DSC) were conducted to evaluate thermal stability, degradation steps, and thermal events. The use of different initiator systems did not modify the thermal events or the thermal stability of each of the dimethacrylate resins. Results show a substitution of system 2 (toxicity) by system 3 (low toxicity), which had a good conversion velocity and total conversion in some monomers, is plausible.