Everwide Newsletter
Everwide Newsletter No.330
Date:2020-08-03

Experiment report § Transparent flame-retardant epoxy resin

Inorganic flame retardant used in the resin, the hardened product will become opaque. For transparent formulations, organic flame retardants that are compatible with the resin must be selected. This is the most difficult part of formulation development. We have studied halogen-free, transparent flame-retardant formulations, and have achieved success in the two hardening systems of acid anhydride and mercaptan. Recently, we have developed a two-component amine hardener formulation. The use of phosphorus-based flame retardants can also meet the requirements of transparent flame retardancy. The new product has many features: (1) A:B=2:1, it can be mixed with a hose, the viscosity is below 10,000cps (Figure 1, 2); (2) Tg after curing at room temperature is 50℃; (3) ) High surface hardness, Shore D is between 75-80 (Figure 3); (4) Excellent flame retardancy. Place a 3mm test piece on the flame and burn for 10 seconds, then remove it from the fire source and record the number of seconds of its burning, repeat twice. We measured the number of seconds to extinguish the flame as 0 and 1, which meets the requirements of UL94 V-0 (Figure 4). Phosphorus-based flame retardants will slow down the reaction of amines and epoxy resins, and will also cause the surface of the hardened product to absorb moisture and whiten. This will be relatively obvious in a low-temperature and high-humidity environment, which is where breakthroughs are needed in the future (Figure 5).
─ Author: Miss Du Rui Yi
About Yongkuan § Zero barriers to communication

This year, we cooperated with Chiayi University to offer 80 hours of business Chinese courses within the company to improve the Chinese communication skills, vocabulary use and language acuity of foreign R&D and business colleagues. Through the oral and written examinations before class, after understanding the level of colleagues, and then selecting the appropriate textbooks, the course will be officially launched (Figure 1). The learning objectives are divided into two stages: the first stage starts with a solid foundation of communication skills, and the second stage strengthens the relevant language required for the work. The main teaching axis is books, with contextual teaching for dialogue exercises, and practical homework exercises to promote learning benefits (Figure 2)! Except for the authentic teachers, every colleague is a small teacher. Everyone gets along with each other day and night, and it won't take long to listen and talk. These colleagues will definitely lose their Chinese.

Knowledge Exchange § Will sensitizers definitely increase the reaction rate of photohardening?

The light hardening resin mainly relies on the photoinitiator to absorb light, which then initiates the subsequent polymerization reaction. Each initiator has its maximum absorption wavelength, and light longer than this wavelength will not be absorbed and there will be no subsequent reaction. Some formulations contain pigments, substrates contain light absorbers, and even the light source itself does not have short-wavelength light... all of which cause the photoinitiator to fail to react. Sensitizers can absorb light with longer wavelengths, and then transfer these energy to the photoinitiator to make it react, so the overall reaction speed can be faster. Some photoinitiators themselves can absorb long-wavelength light, and the absorbing position overlaps with the sensitizer. The two rush to absorb the same wavelength of light, which will slow down the reaction.

Biweekly good ball § 13 heroes

To be honest, I used to be afraid of dogs. At the beginning, because the farmland in the family needed to be taken care of, I decided to raise three dogs to help me. After getting along with each other over time, I let my guard down. Unknowingly, we have kept more and more, and now we have a Corgi and twelve Meeks. They bring me a lot of happiness and psychological comfort. When I feel worthless, the dog never despises me, and still loves me as always; when I cry, the dog licks my ears, as if comforting me, "Sister don’t cry, we are all by your side." These little actions healed my helpless me several times. Every weekend, I will accompany them to play and feed good food. These daily small fortunes are an integral part of my life. In order to let the dogs have a good place to stretch, we took care of them in a free-range way, and because of this we once lost a dog. It was very sad to find that the whole family was searching and searching along the foot of the mountain, but still couldn't find the trace. In order not to let the regret happen again, so I helped them all wear tags and keep contact information. What impressed me the most in the process of raising a dog was a stray dog: it slipped out of our farm again and again based on memory and ran back to his previous home. After many times, the former owner was also deeply moved and decided to stay again. Down it. Dogs are like our family members. Although they only have a short life of more than ten years, if we can stay together, there will be no regrets.
─ Author: Miss Qiu Manyun
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