Experiment § Determination of resin drying time
We refer to ASTM D5895-03, mix the resin and curing agent and apply the thickness to 76μm on the glass sheet, and use the drying time recorder (Figure 1) to evaluate the characteristics of the resin at different stages of curing. The recorder operating principle of the recorder is to use the probe on the instrument to move on the resin at a fixed speed (Figure 2). The resin will leave different probe marks at different curing stages (Figure 3). I: set-to-touch time: Before this time, the resin is liquid. After the probe scratches the surface of the liquid, the liquid will adhere tightly, so there will be no scratches. The resin will not flow after the finger touch time, and the finger will not stick to the hand. After this time, the film is very soft and weak and will be scraped off by the probe. II: tack-free time Tack-free time (non-stick time): This time represents the resin reaction to a certain extent, it has basic strength, and it also starts to adhere to the substrate. The resin after the tack-free time is not easy to be scraped off the entire surface of the substrate by the probe, and only traces of intermittent roughness are left. III: dry-hard time: The resin after this time has considerable strength, so the probe can only leave a slight trace on the surface and cannot penetrate the bottom. IV: dry-through time: This time represents that the resin has a high reaction rate, and the probe cannot leave any traces on the film.
—Author：Mr. Dong-Qiao, Yang
Activity § The first beach cleaning activity
Taking advantage of the make-up day last Saturday, we specifically called on several colleagues to go to clean the beach. The coast adopted by Everwide is located behind the Sihu Coastal Botanical Garden in Yunlin County. Everyone is working hard to clean the coast under the scorching sun. A lot of rubbish is stuck in the cracks of the stones, and the strong colleagues have to remove the stones one by one to clear the rubbish smoothly. In just two hours, fifty pieces of trash were cleared out, and we even cleared out a sofa chair! These rubbishes have been floating on the sea for a long time for various reasons and then washed to the coastline to stay, causing environmental pollution and affecting marine ecology. Everyone thinks this event is very meaningful, and we will call on more colleagues to come together next time. We believe that continuous efforts to maintain the cleanliness of the coast will enable Taiwan to continue to be beautiful!
Knowledge § What factors affect the dielectric loss of polymers?
The polymer is affected by the external electric field, and polarization occurs through the movement of the chain. For example, the electric field directly above the polymer is positively charged, and the polymer will move through the chain to direct the partially negatively charged functional groups in the structure directly upward. When the external electric field is an AC electric field, the movement of the polymer chain will change as the direction of the external electric field changes. The energy consumed by the movement of these molecular chains will be expressed as thermal energy, which is called the dielectric loss (Dissipation factor). The property of dielectric loss has a great relationship with the movement of polymer chains, and the variables that affect it include polymer polarity, temperature, and electric field frequency... etc. The lower the polarity of the polymer, the less the external electric field will be induced, and the lower the dielectric loss. The lower the temperature, the lower the ability of the polymer chain to move, and the smaller the dielectric loss; at high temperatures, the molecular chain is soft and can rotate freely without consuming any energy, and the dielectric loss is not high. Macromolecules near Tg are about to begin to move in a large range, but there is still a lot of resistance between molecules. At this time, the movement of the molecular chain with the change of the electric field consumes the most energy, and the most dielectric loss often occurs. The influence of the electric field frequency on the polymer chain is difficult to predict. The influence of the electric field frequency on the dielectric loss of the same material at different temperatures is different, mainly due to whether the molecular chain can respond to changes in the electric field and move easily or not.
Living § Set a good example for the next generation
Humans are learning animals. We imitate and learn every move of adults since we were young, and then let ourselves do something on our own. Sometimes, our inadvertent small actions, children will see it in their eyes and remember them in their hearts, and show them over time. The sitting posture, the walking posture, the way of eating, the way of talking, and even the mantra are all behaviors that children imitate and learn. I have been smoking for more than ten years, and the happiest thing every day is a happy time with a cigarette. After becoming a father, I will think about avoiding smoking in front of children, which will affect their health. A while ago, I discovered that my son started to draw with a pen or chopsticks and learned how I smoked. It turns out that my daily smoking behavior has long been deeply imprinted in the heart of the child. In order not to continue to affect my children, I am determined to start quitting smoking, set an example, and let them know that smoking is bad behavior! Although I may not be the most powerful dad, I hope to set a good example for the children, subtly and prevent them from learning bad habits. Now it is unwise to spend money to enjoy the fun of smoking. When you are old and get sick, you have to spend more medical expenses for treatment. It is really unwise. For your own health, for the sake of your family, quit bad habits, and live healthily!
—Author: Mr. Yu-Ren, Chen
