Chapter 98: Stay in Zhang Jiang

　　Waste liquid is usually packed in 500ml glass reagent bottles of Sinopharm, or packed in 4 liters, 5 liters white plastic buckets.
　　 Need to use a marker to mark that this is waste liquid, and also indicate the main components of the waste liquid.
　　 Like the main components of their laboratory waste liquid, they are all commonly used organic solvents.
　　 If it is a strong acid, a strong base, a strong oxidizer, a strong reducing agent, or a special waste liquid such as a fluorine-containing waste liquid, it is best to pre-process it by yourself before handing it over to the waste liquid warehouse.
　　 If it can't be handled, it is necessary to explain the situation to the waste liquid warehouse to prevent them from treating it as ordinary waste liquid and causing safety accidents.
　　 The two of them processed the waste liquid and solid waste and returned to A502 again.
　　 At this time, the color of the solution in the extraction tube of the Soxhlet extraction device was faintly blue.
　　 This shows that the chloroform solvent is not enough to extract the sample, and it will take some time.
　　 Xu Qiu was not idle either, he came to the rotary steaming equipment to check the circulating cooling device.
　　 found that only about half of the coolant inside it was left. It seems that the coolant inside has evaporated a lot and needs to be refilled.
　　 This machine should have not been activated for almost a year. Duan Yun does inorganic synthesis, and usually he does not use rotary steaming.
　　 Xu Qiu added ethylene glycol and deionized water in a 4:6 volume ratio, started the device, and started the refrigeration and circulation.
　　Fortunately, the machine is not broken. The temperature indicator on the digital display panel is beginning to drop from 20, and the coolant in the pipeline can be seen circulating with the naked eye.
　　 The circulating cooling device is fixed, and Xu Qiu starts to check the water pump.
　　 The water in the pump is still clean and does not need treatment. Maybe Duan Yun has been useful recently.
　　……
　　 After half an hour, the Soxhlet extraction was completed, and the liquid in the extraction tube was basically colorless.
　　 Xu Qiu shut down the device, after the solution is cooled, transfer the solution in the Erlenmeyer flask to the eggplant-shaped flask in a fume hood.
　　 began to steam.
　　 When about 15ml of chloroform solvent remains in the eggplant-shaped bottle, stop the rotary steaming.
　　 Then plug the mouth of the bottle with a rubber stopper, put the eggplant-shaped bottle on the rubber bottle holder, and set aside.
　　 He used the same method again, and processed the other three bottles of solution to the remaining 15 ml of solution.
　　 Then, the chloroform solution was dropped into methanol to precipitate a solid polymer product, which was filtered.
　　Wrap the product with filter paper and put it in a vacuum oven.
　　 Finally, Xu Qiu recycled the chloroform obtained by rotary steaming, put them back in their original bottles, and marked a big "back" with a marker on the bottle label, indicating that it was recycled chloroform.
　　Theoretically, the purity of the chloroform collected after rotary evaporation is relatively high.
　　 It is the product of distillation. If the collection bottle is clean enough, the purity is equivalent to distilled water.
　　The main reason is that Xu Qiu used nearly one liter of chloroform solvent, and it would be too wasteful to treat all as waste liquid.
　　 Chen Wanqing was watching the whole time. In fact, she couldn't help much because there was only one rotary steaming machine.
　　 "School brother has worked hard, let me handle the next batch of products." Chen Wanqing said.
　　 "Okay." Xu Qiu glanced at the time, it was past four in the afternoon, and then asked:
　　 "It's past four o'clock, do you still respond today?"
　　 "Put it, it's all here, just take the late school bus back at night, the last school bus is 9:30." Chen Wanqing said.
　　 "Then I will make a PBT4T today, and then make a P2FBT4T, that is, two fluorine atoms are added to the BT unit, and other conditions remain unchanged for the time being." Xu Qiu said.
　　 "I will make three of them today to adjust the molar ratio of A unit in the terpolymer, 1:1, 3:7 and 7:3." Chen Wanqing said:
　　 "In this way, the task today is quite arduous."
　　 "Yes, come on." Xu Qiu said.
　　 Take a break and continue the experiment.
　　 Re-evaporate toluene, set up a reaction device, and make a nitrogen ball.
　　 Fortunately, Xu Qiu came prepared this time. For the new material P2FBT4T, he has obtained the relative molecular weight of the monomer in the Chemdraw software in advance and calculated the quality of the feed.
　　The reaction conditions are still being explored, so this time it is still a small amount of feed. The total amount of the two monomers is less than 200 mg.
　　 A little accident occurred during the experiment.
　　 The toluene was re-vaporized for an hour, but the indicator did not turn blue.
　　 Xu Qiu concluded that the reason for the rapid blue change in the previous two times was that the toluene solvent had just been opened and the water content was extremely low.
　　 And this time it should be because the toluene has been in the air for a long time and absorbed a small amount of water.
　　Theoretically, it is enough to reflux for a while.
　　 The time was close to the meal, and the two decided to let the toluene continue to be re-steamed and went to eat first.
　　……
　　 After dinner, return to the laboratory.
　　 The indicator in toluene has turned blue.
　　 Continue the experiment, but there are no more accidents after that.
　　 Fighting for three hours in a row, the two cast all five responses.
　　 Xu Qiu not only voted for two of his reactions, but also helped the senior sister complete one.
　　 It's nine o'clock in the evening.
　　 Xu Qiu took out four polymer products from the vacuum oven, weighed, bottled, and marked.
　　 While operating, he said:
　　 "Senior sister, how long do you think we should take for this batch of reactions?"
　　 "Let me think about it," Chen Wanqing thought for a moment and said:
"We voted at about 8 o’clock in the evening. If we set a 12-hour response time, we have to come over at 8 o’clock tomorrow morning to turn off the reaction~EbookFREE.me~ It’s better to set it at 18 hours, so we will close the reaction at 2 o’clock in the afternoon. , Time doesn’t have to be so rush."
　　 Xu Qiu made three reactions in the simulation laboratory, and after only 12 hours of reaction time, a large amount of polymer had been precipitated.
　　 Thinking of this, he made a decision:
　　 "Well, I live here today, and I will wake up at around 8 o'clock tomorrow morning to watch the progress of the reaction.
　　 If a large amount of polymer has been precipitated, stop the polymerization and start the end-capping reaction;
　　 If there is no product precipitation, just wait for you to come over, how about? "
　　 "All right, you have to pay attention to safety when doing experiments here alone," Chen Wanqing hesitated:
　　 "Why don't I... forget it, then I'll go first, or I won't be able to catch the school bus."
　　 After that, she carried her schoolbag and flew away like a gust of wind.
　　 Xu Qiu looked at her back and then at the time, it was only nine ten ten.
　　 It’s at most five minutes away from the school bus stop. What did the elder sister do in such a hurry, even forgot to take the processed samples.
　　 Xu Qiu shook his head and entered the A502 laboratory for finishing work.
　　 First, put the processed four batches of samples into a vacuum tank containing monomers and keep them properly.
　　 Then slowly pour sodium-containing toluene into absolute ethanol. After the sodium reaction is complete, pour it into the waste liquid bucket as a waste liquid.
　　 Metal sodium can react mildly with ethanol, so ethanol is generally used to treat waste sodium.
　　 It is better to use new toluene next time, otherwise the longer the toluene is left outside, the re-steaming time will only get longer.
　　 Next, soak the dirty bottles that were created today in an alkaline tank.
　　 Finally, clean up the laboratory and shut down the water, electricity and gas in the laboratory.