Experiment § Two-component modified silicone potting adhesive (1)
There are many types of one-component moisture curing on the market, commonly including Silicone, modified silicone (MS), polyurethane (PU), etc. The common core problems of one-component moisture curing products are: 1. Moisture comes from the environment and is not stable. 2. It takes time to wait for moisture to penetrate into the resin, and most of the curing depth has a limit (it is recommended not to exceed 1 cm). Taking a typical one-component glue as an example, the curing depth only reaches 3.3 mm after 24 hours at room temperature, and the reaction rate is not good enough to accurately measure the hardness (Figure 1). Everwide developed FS211 two-component type 1:1 modified silica adhesive to improve the above shortcomings, hardness (Shore 00) = 57 after standing at room temperature for 1 hour, and curing depth 15 mm. Figure 2 shows that FS211 cured product has been tested at 85°C/85%RH for 500 hours, with a 23% increase in hardness (Shore 00) and a 50% increase in aluminum vs. aluminum adhesion. These figures indicate that high temperatures and humidity will cause further reactions in the resin, resulting in a slight improvement in performance. Of course, there are other examples where the resin absorbs water and reduces hardness in high temperature and humidity environments, and temperature or moisture may also cause structural aging. More test data will be shared in the next issue, please stay tuned. ——Author: Mr. Zhe-Yong, Lin
Activity § Wonderful activities during the summer vacation
Summer vacation is the most happiest time of the year for children because they can have fun to their heart's content. This year, Everwide also brings a series of exciting activities for the summer vacation. In addition to Everwide Chemical Camp, there are parents and kids hand-made wall clocks, hand-engraved seals, and shrimp fishing activities. In the activity of making a hand-made wall clock, you need to put clay into a mold and press it into a triangle, then pick up a brush and color it (Figure 1, 2). Hand-engraved seals are also fun, you can design your own patterns and engrave them to create a unique seal (Figure 3, 4). The exciting shrimp fishing event. Shrimp fishing requires patience and cannot be noisy. Someone have seven shrimp were caught on that day, and ate them in the lunch (Figure 5).
Knowledge § Why are the autocatalytic reactions of epoxy resins and amines sometimes not obvious? (1)
The reaction between epoxy resin and amine curing agent will create a hydroxide structure (OH group, Hydroxide group), which is the catalyst for the reaction of epoxy resin and amine. The product is the catalyst of the reactant, and as the reaction progresses, the catalyst will become more and more, and the reaction speed will become faster, which is characteristic of the auto catalytic reaction. In contrast, the more products generated by the reaction, the more catalysts and fewer reactants, which leads to a slower reaction. These two factors influence each other, resulting in a maximum speed of the auto catalytic reaction occurring during the reaction. Generally, the concentration of reactants is the highest at the beginning of the reaction, so the reaction speed is the fastest, and the reaction speed decreases with time, which is the biggest difference from auto catalytic reactions.
Living § Everwide Chemical Camp
Academically, I was good at liberal arts and never knew anything about natural science, so I came to chemistry camp with curiosity. The first lesson was to listen to the story of a scientist: "The Life of Faraday". With the rise and fall of the voice, it also brought me into the world of science. After listening to the story, I began to briefly understand the principles and functions of science, including Dyne pen, anti-fog film, fingerprint-resistant film, anti-privacy film, and anti-glare film of "water drop angle". Get an overview of these concepts by doing it myself. One class that was particularly interesting was where everwide employees from Thailand, Vietnam, and Indonesia introduced their countries, including food and local culture. Their humorous introduction to Southeast Asia's unique food was an eye-opener for me. He also introduced chemical formulas and chemical chains and taught us to make chemical chain structures out of clay, which was really fun. I also experienced the test method of pressure-sensitive adhesive, and the bottleneck caused by the initial unfamiliarity with the measurement method was solved under the guidance of everwide employees. Finally, they introduced the "father of modern chemistry" - Lavoisier, Antoine(-Laurent), and the practical operation of the "Conservation of mass", which gave me a deeper understanding of Lavoisier, Antoine(-Laurent). The memories and experiences of the three days chemistry camp, i will never forget. I would like to thank everwide employees for their efforts and contributions, make the chemistry camp can be held so smoothly, and I have learned a lot from it!
——Author: Pin-Yu， Wang
