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Everwide Newsletter No.261

Experiment § Influence of red phosphorus flame-retardant

Compared with other phosphides, red phosphorus has a high phosphorus content and a low addition amount, which has little effect on mechanical properties, and there is no problem with plasticizing polymers. So it is a good flame retardant. However, in the application of red phosphorus in epoxy resin, there have been cases where phosphoric acid was reacted to cause IC corrosion or refrigerator parts damage. We put the resin formula A without flame retardant and the formula B with red phosphorus and aluminum hydroxide as flame retardants respectively in different high-temperature environments, then crushed and soaked in water for extraction, observed whether the phosphorus concentration measured by IC is related to PH. Put the resin in an environment of 195℃/15hr, the PH of formula A and B are 6.5 and 6.2 respectively, phosphate concentration is 0 and 5.5ppm. If the resin is placed in an environment of 220℃/15hr, the PH of formula A and B are 5.7 and 5.1, and the phosphate concentration is 0 and 36.1 ppm. Based on these data, we can know that the aging of polymers produces acidic substances. But it seems not sensitive to estimate the phosphate concentration based on PH and the main reason is that the PH of red phosphorus in the polymer is affected by other substances. Place aluminum hydroxide, red phosphorus and the mixture of aluminum hydroxide and red phosphorus at 195℃/15hr, the PH of these three substances is 9.1, 3.3, and 4.6 respectively. Because the product of aluminum hydroxide and red phosphorus at high temperature will undergo acid-base neutralization to reduce the amount of PH change, IC is better for phosphate.

—Author: Dr. Ming-xu, Li


Activity § Trench engineering

The built factory will not remain the same all the time, it will change with the changes in regulation. In the past few years, air emission treatment facilities accepted water scrubber, but later required activated carbon adsorption (Biweekly 141). The solvent warehouse was originally built by the wall, but it was later required to be 20 meters away from the wall (Biweekly 173). Factory lighting originally used ordinary pipelines, but later changed to explosion-proof pipelines (Biweekly 258). The fire brigade suggested that we dig trenches around the production area to prevent raw materials from overflowing outside the factory. We need to dig a leachate collection well at the end of the trench and set up an exhaust pipe and exhaust duct. Although the regulations are complicated, we still try our best to do it. We will use the weekend to carry out the project and strive to excavate this week and cover it next week. Determined to become a first-class factory.


Knowledge § About halogen flame retardants

Halogen flame retardant(mainly chlorine and bromine) has high flame retardant efficiency, whether it is connected with polymer chains or added as an additive, it will have a good effect.

In the same flame-retardant effect, the halogen system has relatively little effect on the polymer, and the formulation design is more flexible. Halogen flame retardants produce a lot of smoke when burning, and the smoke is toxic, which is really a serious disadvantage in the application. But the halogen system gradually fades out of the market and is related to the following environmental issues: 1. Much environmental monitoring found traces of halogen flame retardants everywhere. 2. When waste is incinerated, strong acids such as hydrochloric acid are produced, which may damage the service life of the incinerator. 3. There is a risk of dioxin when it is burned. Because of the above problems, some halogen flame retardant by RoHS at first, and later REACH also listed many halogen flame retardants. Many electronics industries hope to use environmental materials(The content of chlorine and bromine should be less than 900ppm, and the sum of the tow should be less than 1500ppm), so the halogen flame retardants will be restricted.


Living § Exchange diary

After my child went to school, I began to expect myself not to be “a helicopter parent”, not to over-intervene and protect the child. As the children grow up, I try to be a good friend with the children, but when they went to middle school, everything became different. The children who enter adolescence gradually don’t like to talk or chat with adults, It is difficult for us to understand each other’s thoughts, and our hearts became more and more strange. One day when I was cleaning at home, I found an opened diary on my daughter’s table. Because of curiosity, I was going to take a look at the contents of the diary, but when my daughter ran into and she shouted angrily” Mom, how can you peek at my diary, so you don’t respect me, you know?” I wanted to know more about my daughter originally and I didn’t expect to be self- defeating. We have been in a cold war for many days. Because I was melancholy about this matter for a long time, my colleague suggested that I communicate with my daughter by exchanging diaries, and my first diary is to confess with my daughter. Although the child said that exchanging diaries is a very old-fashioned thing, we also started to exchange each other’s thoughts and everything in life in this way. Respect and mutual trust are building bridges between people. If one of them is lost, the distance between the two hearts will grow farther and farther. If you and I also thinking about how to build good communication with your children, maybe You can try the practice of exchanging diaries to learn your children’s thoughts slowly and make friends with them to become closer.

—Author: Miss. Jane Shirley

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