聚醚消泡剂（Polyether defoamer）

1、聚醚消泡剂（Polyether defoamer）Polyether defoamerPolyether type defoaming agent defoaming agent is one of the most important products in the varieties, non-toxic, no smell, no stimulation and features easy to disperse in water, in addition to the general industrial applications, can also be used in food,

2、fermentation, cosmetics and pharmaceutical industries, is the silicon defoaming agent can not replace the. Polyether type defoaming agent can be divided into polyol, fatty acid ester and amine ethers according to its starting agent, which is widely used as polyol and fatty acid ester. The production

3、 of polyether defoamer in our country started in 1969 and was firstly applied to antibiotic fermentation. These products mainly include GP type glycerin polyether and GPE type polyoxyethylene (poly)Propylene oxide) ether and PPG type polypropylene glycol etc. Although polyether defoamer is widely us

4、ed, there are still some gaps between some properties and silicone defoamer. Therefore, it is necessary to innovate the molecular structure of polyether in order to obtain good defoaming properties. The authors investigated the synthesis of polyether defoaming using several different starting agents

5、The performance of the agent, focusing on the polyol defoamer block, chain length, different molecular weight changes on the influence of antifoaming properties was studied, at the same time to inspect the defoaming agent dosage, temperature and pH value application conditions, and the corresponding

6、 rules of Suzhou Huarun.The instrument and drug WHF a 2 type autoclave, automatic instrument control system; ZD.2 type vibrating machine, pH meter, 600mL graduated cylinder, stopwatch.Glycerol, lauric acid, twelve amines, hydrochloric acid, sodium hydroxide and potassium hydroxide are chemically pur

7、e; ethylene oxide and propylene oxide are industrial gradeThe amount is greater than 99% and the moisture content is less than 0.01% and 0.1% respectively.Synthesis of an experimental polyether defoamer - Suzhou HuarunThe amount of initiator and catalyst into autoclave, stirring with nitrogen replac

8、ement 3 times, heating, in the specified temperature under vacuum dehydration to cool so far; ring opening polymerization at a temperature below a certain order of epoxide, respectively, adding a certain amount of ethylene oxide and propylene oxide. After the addition, aging 40min, then cool down to

9、 80C discharge, and obtain polyether type defoaming agent.Preparation of foaming liquidWith distilled water to twelve sodium dodecyl sulfate quantitative completely dissolved in the beaker, the preparation of 1% aqueous solution as foaming liquid, foaming liquid pH value according to the requirement

10、s of performance evaluation using hydrochloric acid or sodium hydroxide solution was adjusted, the system temperature can for heating or cooling according to requirements.Performance evaluation of defoaming agentsTo transfer a good foaming liquid 100mL 600mL with accurate calibration in a cylinder,

11、cork cover tightly and clip on the oscillating machine for the 100 oscillation (ensure cylinder bubble oscillation, full) quickly after take off. Then the following performance evaluations can be performed separately.Evaluation method of bubble breaking performanceUse the dropper to accurately and e

12、venly add a quantitative defoaming agent to the upper port of the cartridge cylinder. Immediately after the addition of the stopwatch, record the bubble height at different times. Each sample is repeated 3 times in parallel. The average value of the bubble height was calculated as the criterion of d

13、efoaming agent performance, the higher the bubble, the worse the bubble breaking performance of the defoamer, and the better the bubble breaking performance.Bubble suppression performance evaluation methodThe bubble height was recorded, and each sample was repeated 3 times in parallel. The average v

14、alue of the bubble height was calculated. The bubble height was higher than that of defoaming agent, indicating that the defoaming performance of the defoamer was worse, otherwise, the better.Determination of penetration timeUsing the dropper to accurately and uniformly vector cylinder port adding q

15、uantitative defoaming agent, and immediately after opening the stopwatch, carefully observe and record the defoaming agent through the foam layer at the surface of the time required to repeat 3 times and take the average as defoamer permeability evaluation criteria.Results and the effects of differe

16、nt starting agents on the performance of polyether defoamer were discussedUsing the traditional GPE type polyether defoamer structure, namely the initiator and polymerization of propylene oxide first, then polymerization with ethylene oxide, ethylene oxide with molecular weight of 3000, accounting f

17、or 10% of the total, with twelve different initiator, glycerol and lauric acid with Amine epoxide 3 typical polyether defoaming agent the synthesis of. Experimental conditions: 20 DEG C, pH=7.0, dosage 0.05%. Results of comparison of performance of different starting agents and defoaming agents are

18、shown in table 1.Table 1 performance comparison of polyether defoamer synthesized with different starting agentsDefoaming agent, foam suppression, /mm foam height0min, 1min, 2min, 3min, 4min, 5min, 6min, 7min, 9min, 8minPropylene glycol 260600520460410365, three, 320270230190160Twelve amine ether 32

19、0600545495450395, 350305265235210Lauric acid ether 365600560515475430, 395360330295265As can be seen from table 1, the performance of the 3 defoaming agents synthesized by using the above structure proportion is quite different,C three ether foam high in bubble or in the different time of bubble bre

20、aking are low, so the defoaming properties are significantly stronger than twelve amine ether and laurate, but the optimal structure of twelve amine ether laurate and remains to be studied further. In this paper, the structure and properties of polyol polyether are studied.Influence of different blo

21、ck modes on defoaming properties - Suzhou HuarunTaking glycerin ether as an example, two segments of GPE (glycerol: PO:EO) and three segments of GPEP (glycerol: PO:EO:PO) were synthesized, with molecular weights of 3000. The ratio of glycerol, ethylene oxide and propylene oxide was fixed, and ethyle

22、ne oxide accounted for 10% of the total, of which three of the GPEP tail section accounted for 2% of the total. The experimental conditions are: 20 DEG C, pH=7.0, and the dosage is 0.05%. The influence of the above two block methods on defoaming properties was investigated. The results are shown in

23、table 2. From table 2 we can see that in the bubble, the three paragraph of the GPEP antifoaming performance was significantly better in the two paragraph of the GPE; in terms of bubble breaking, two different block mode has its own characteristics, the two paragraph of the GPE in the 4min before th

24、e global high obviously the three section below the GPEP, pre GPE type of bubble breaking faster than GPEP, but the GPEP type of global high in 4min was less than the GPE type, GPEP type defoaming agent for foam breaking ability, and the GPE type defoamer bubble breaking of stamina is obviously inad

25、equate. On the whole, the GPEP type of defoaming performance of the three paragraph is better than that of the two paragraph of GPE.Table 2 Influence of different block modes on defoaming propertiesBlock mode foam suppression /mm foam height0min, 1min, 2min, 3min, 4min, 5min, 6min, 7min, 9min, 8minG

26、PE 260600520460410365 320270230190160GPEP 180600555485415350 295250210175140Effect of different epoxy segment length on defoaming properties: Suzhou HuarunThe GPEP type block with glycerol as starting agent, with molecular weight of 3000, was used to synthesize polyether defoamer with different leng

27、ths of ethylene oxide and epoxy propane chain. The conditions were: 20oC, pH=7.0, and the dosage was 0.05%. In order to compare the bubble breaking properties, the bubble breaking curves were taken at 6min.Effect of chain length of ethylene oxide on defoaming propertiesFor GPEP type three block poly

28、ether, the tail section (4% of total amount) was fixed, and the length of ethylene oxide chain was changed. The mass fraction of ethylene oxide has a great influence on the performance of polyether defoamer. In the aspect of foam inhibition, the mass fraction of ethylene oxide is about 4%, and the b

29、ubble height is low, which shows good foam suppression. This may be due to the situation of initiator, molecular weight of ethylene oxide, propylene oxide content in the lower segment with relative hydrophobicity is longer, eliminating dissolved agent molecules in the foam system becomes worse, whic

30、h will prevent and reduce the degree of dispersion of gas in the foaming system, reduce the formation of foam ability reflects good bubble. On the other hand, ethylene oxide high content of polyether defoaming agent dissolved in the foaming system, even in the surfactant solubilization foam system,

31、loss of gas in the foaming system of dispersion process preventing effect leads to suppression of bubble decreased or even lost bubble. From the bubble breaking curve: in the vicinity of ethylene oxide mass fraction of 6% of the global minimum, the bubble breaking performance is very good, it may be

32、 a molecular with low content of ethylene oxide segments will increase into the film speed and degree of liquid film on the surface of spreading, more easily spread to the gas-liquid membrane surface to have effect, thus exhibit excellent defoaming, with ethylene oxide content increased, the relativ

33、e length of epoxy propane segment will be shortened, which will affect the defoamer molecules in the liquid film on the surface or interface state, resulting in the decrease of defoaming agent through the formation of new molecular film strength and viscosity, the bubble breaking performance decline

34、.Influence of chain length of propylene oxide on defoaming propertiesFor the GPEP type structure of three block polyether, the mass fraction of ethylene oxide 6%, molecular weight is 3000, so that the total amount and two propylene oxide segments were fixed, but here the two sections of propylene ch

35、ain segment length can be changed. The change of the chain length of the latter two segments also has some influence on the defoaming performance. Of course, the length of the last segment of propylene oxide is increased, and the length of the epoxy segment is shorter. According to the bubble breaki

36、ng curve, the content of propylene oxide is near 8%, the bubble height is the lowest, which means the foam breaking is the best,That proper increase of the tail section of propylene chain segment length will help to improve the defoaming agent in gas-liquid membrane spreading and dispersion, but the long tail section of epoxy propane will affect the formation of new film strength, film should not cause rupture, reduce broken foam. From the defoaming curve, with the tail section of epoxy propane content increase, foam height decreased to a certain degree, that defoaming performance has improv