Yongkuan News
Yongkuan Chemical Newsletter-Issue 320
Release Date: 2020-03-16

experimental report § Polysulfide rubber first experience

We have recently committed to the development of liquid polysulfide rubber products. Compared with general epoxy resin and moisture-curing silicone rubber, this material has better effect on rubber adhesion (Figure 1). Polysulfide rubber contains sulfur atoms in the main chain, which makes this kind of rubber products have good oil resistance, solvent resistance, aging resistance, low air permeability and good low temperature flexibility. It also has very good for certain metals (such as copper) Good adhesion effect can be used for low stress applications (Figure 2,3, 10). This material is commonly used in civil construction, automobile fuel tanks or aerospace industries... and is especially used as a caulk material. The only disadvantage of polysulfide rubber is the strange smell of sulfur, which is less pleasing. At present, we are developing a two-component formula, A:B=1:4, which can be made into a single-component moisture-hardening type in the future, expanding our Silicone and MS product lines, customers can have more choices according to different characteristics (Figure XNUMX).

─ Author: Dan Gengchang, Mr. Shen Jing Jie
About Yongkuan § Recent people and events

The epidemic situation of New Coronary Pneumonia is expanding globally. In order to prevent the spread of the virus, the nurses in the factory are specially invited to conduct anti-epidemic measures. In addition to taking everyone to measure body temperature, it is also important to wash hands frequently, and the correct way to wear a mask... etc., so that the virus can "Get Out" (Figure 1). A new batch of internships has been arranged for internships in different departments. I hope everyone can experience different sparks after six months of Yongkuan's life. This is also a good opportunity to learn from each other (Figure 2)! In order to promote the knowledge exchange of R&D colleagues, we implemented the "R&D Short Lecture" (Figure 3). The speaker spent 15-20 minutes to share the key analysis of the experiment, the key knowledge of product development, and the search channel for professional data. Unlike the two-hour course, which has been around for a year on Wednesday night, the "R&D Short Lecture" emphasizes fast food, immediate availability, and increased probability of collision of knowledge. In the changing trend, the content and methods of learning, the purpose of learning has become increasingly diverse, we will continue to try.

Knowledge exchange § Why do soft epoxy resins react slowly?

The general epoxy resin epoxy group is connected to the aromatic structure, the reactivity is relatively high, and the structure is relatively hard. Aliphatic epoxy resins are often added to soft epoxy resins, and epoxy groups are attached to the aliphatic structure, and the reactivity is relatively lower, which is one of the reasons for the slowdown. Another reason for the slower speed is the concentration of functional groups. Only when the structure of the material is soft, the molecular weight is large, and the bridging density is low, can the soft characteristics be exhibited. The functional group concentration of this formula is relatively low, and the chance of collision and reaction becomes less, so the reaction speed will become slower. The reaction rate of soft resin is slow, and the reaction rate at room temperature is more unstable. After a long time, the reaction rate is further improved, and it seems to have a tendency to become hard. If it can be hardened by heating, this uncertainty may be avoided.

Biweekly strike § Reminiscence of reading classics

I have been involved in parent-child Bible reading classes for more than three years, and every Friday is the whole family Bible reading night. The reason for joining was very simple. When one day I took the child to the noodle stall, the boss lady said that the child was too "vulgar." If you think about it for a long time, this is indeed the case, because the holidays are at home, and my children and I also lack interaction and common topics, so I decided to find out. Every child in the Bible study class is full of confidence. One of the fourth-grade little girls' typhoon's steady reading and the fan dance performance of the graceful and graceful performance made me admire the movement. The happy atmosphere in the class completely subverts the monotonous and dull impression of the reading class. The original reading can also be vivid and interesting. The children will also want to participate actively, in order to grow up and set a good example, so we have continued to participate. After attending several issues, the relationship became more harmonious in addition to knowing more about the children. I heard the feedback from neighbors, relatives and friends one after another, "Your children will take good care of our children!", "Your children are so enthusiastic!" I am very pleased. Watching the child's transformation, I also started to take charge of the reading class, although it was hard but it was as sweet as a cake. "Right to the road, you are not afraid of the road." Last year, we took our children who have never been abroad and went to Malaysia to communicate with the local Chinese reading classes. The journey benefited a lot and also realized the importance of promoting culture. Moral education has taken root since childhood. I look forward to your joint efforts, and welcome you to increase your knowledge!
─ Author: Mr. Lin Cheng Hong