Everwide Newsletter No.216

For epoxy resins cured at room temperature, the curing agent is mostly an amine system. Because this kind of curing agent has strong alkalinity and high hydrophilicity, it is easy to absorb moisture in the air, causing the surface of the cured product to produce patterns due to high water content, and more severely, it will produce an atomization reaction. (Extended reading: Bi-weekly report 90). Figure 1 shows the surface of a cured epoxy resin that does not absorb severe moisture. Figure 2 shows a formula that will severely absorb moisture, and atomize after curing. This kind of surface texture is caused by moisture absorption, and of course, it is related to the weather. The situation will be better on sunny days and more serious on rainy days. When the room temperature is high, the reaction speed is fast, the moisture absorption time is short, and the surface condition is better, but when the temperature is low, the surface condition is worse. When heating and baking, the reaction speed is fast, the environmental humidity is low, and the surface will not have defects caused by moisture absorption. The easy-to-hygroscopic formula does not have much impact on the adhesive, because the resin curing process is covered by the adhesive and is not exposed to the outside surface, so it will not be affected by moisture. In addition, the proportion of unreacted amines after the resin is cured is not high, and there is no problem of excessive water absorption. However, this kind of formula used for pouring materials will have the problem of unsightly surface, so it is not easy to be accepted by customers. From a chemical point of view, the use of aromatic amines with lower basicity, fatty amines with stericobstacles, modified amines with non-hydrophilic structures...all have the potential to improve the shortcomings of moisture absorption. All in all, multiple considerations are needed to determine the solution.

—Author: Mr. Zhi-Yu, Huang

The asphalt pavement in the factory has a history of nearly ten years. After years of crushing by tank trucks, large trucks, and coupling vehicles, there are signs of gradual damage. In addition, some pipeline projects have dug the road surface a while ago, so we took this opportunity to remove the road surface of the whole plant and re-lay the road. The whole process is like "Mechanical General Mobilization." All the engineering equipment that we usually don't pay attention to are all working, which opened our eyes. But the most important element is "people". The work team has a tacit understanding of the division of labor. Some people drive machinery, some handle blind spots, some adjust mechanical parameters, and others observe and command... In fact, they have done the best cooperation. "The division of labor is for cooperation." Seeing others paving the road, I really appreciate this experience.

Thermoplastic polymers are classified into two types crystalline polymers and non-crystalline polymers. If the structure of the molecular chain is neat and orderly, and there are not too many groups that cause steric obstacles, the molecular chains of this plastic may be neatly arranged and tightly stacked to further reduce the potential energy and form a crystalline region, which is a crystalline polymer. The solvent resistance, rigidity, and heat resistance of the crystallization area are particularly good. The crystals will not melt until they reach a specific melting point Tm and absorb a specific heat of fusion. The molecular chains of crystalline polymers are not 100% crystalline, so there is a problem with crystallinity. The regions other than the crystalline region are amorphous regions. The molecular chains in this area are arranged in disorder and entangled with each other, and there are more gaps in the molecular chains, which will behave as Tg. In general, crystalline polymers have both Tg and Tm.

This year I entered the 16th year Everwide chemical. In the past few years, I think the market has undergone very different changes. We may not know a lot of newly developed materials, nor may we have access to good opportunities. I think it is very important to go out and look for different opportunities. From this perspective, 2015 is a very special year. When I went to Japan for the first time in April and watched other exhibits, I knew that we still have a lot of room for improvement. When I visited a German agent in October, I found another stimulus, because just going to Germany with my colleagues is a challenge. I don't have the talent for languages, but with a passion and adventurous heart, and the ability to make friends easily, I went abroad in broken English. We met the Stefan family, Thomas who worked hard, and Penelope who was very friendly. We discussed the characteristics of the European market. He told us that Europe’s requirements for quality are much higher than price considerations. In addition, customers do not consider testing adhesives and only products with good quality can be launched. This perception is not the same as the perception in Asia. Asia will produce and adjust at the same time, so we need time to adapt and accumulate a reputation. But he is very confident in us, and I also believe that we will have good results. He also took me to see the quiet chapel on the mountain. When he encountered a bottleneck, he always went there to sort out his thoughts and start again. In the small church, I suddenly thought about what words should be used to describe the experience of the whole journey? I think the "spirit of never giving up" should be very appropriate. Whether it is ourselves, our partners, or our customers, we must not give up lightly in order to make a real breakthrough and good achievements.

—Author: Miss. Miao-Lin, Ling