过氧化氢氧化法制备发泡剂ADC的研究及其工业化

发布时间：2018-11-20 18:05

【摘要】：发泡剂ADC(分子式H2NCONNCONH2)是一种通用的高效发泡剂，具有发气量大、气泡均匀、致密，分解产物无毒、无臭、不助燃，无污染性残渣等优点，可广泛用作聚氯乙烯、聚乙烯、聚丙烯、聚酰胺、氯丁胶、乙腈胶、丁基胶、丁苯胶和硅橡胶等的发泡剂，且闭孔发泡、常压发泡和加压发泡均可适用。国内发泡剂ADC的生产工艺大多采用氯气氧化法和氯酸钠氧化法，但均不同程度地存在能耗高、物耗大、伴有大量污染物等缺陷。过氧化氢氧化法新工艺在氧化过程除生成发泡剂ADC外，其余产物为水，且过氧化氢易计量，不会有氧化不足或过量问题，生产过程中产品质量和收率稳定，具有无污染、无副产品、产品质量好、产量高、发气量大、无爆炸危险等优点。 本文在对过氧化氢氧化联二脲制备发泡剂ADC工艺过程进行理论分析和小试研究的基础上，在国内首先进行中试，并实现工业化。小试研究得出较佳的工艺条件为：采用新型的铁基化合物为助催化剂，反应液固液比为1：2.5，原料摩尔配比(联二脲：双氧水)为1：1.05，催化剂浓度为1.75g/l，助催化剂浓度为3.0g/l，酸浓度为3.5mol/l，反应温度为50℃，此时反应收率97.44%，产品纯度98.88%。通过理论分析给出相应的反应机理。同时分析表明，联二脲氧化制备发泡剂ADC的过程中，，固液传质为速率控制步骤。从中试过程来看，母液回流对反应收率和产品纯度的影响不大，母液可以一直循环使用。中试还研究确定了工艺条件的浮动范围为：催化剂浓度为1.65g/l~1.85g/l，助催化剂浓度为2.8g/l~3.2g/l，酸浓度为3.3mol/l~3.7mol/l，反应温度为48℃~52℃，此时反应收率在95.14%以上，产品纯度在97.25%以上。工业化研究中采用的工艺条件控制在中试所得的浮动范围内，经过母液数次循环后，反应时间为6h，反应的收率高于92.51%，产品纯度大于96.23%，发气量大于211ml/g，细度筛余物(筛孔38μm)小于0.15%，分解温度大于203℃，加热减量小于0.21%，灰分小于0.03%，完全符合产品的一级品要求。 工业化实践表明，该新方法经济性良好，能耗低，水资源消耗低，更加环保，生产利润有较大的提升，与国内的氯气氧化法和氯酸盐氧化法工艺相比处于先进水平，具有很大的推广和应用意义。
[Abstract]:Foaming agent ADC (molecular formula H2NCONNCONH2) is a kind of general high efficient foaming agent. It has the advantages of large amount of gas, uniform bubble, dense, non-toxic, odorless, non-combustible, non-polluting residue and so on. It can be widely used in PVC, polyethylene, etc. Polypropylene, polyamide, chloroprene, acetonitrile, Ding Ji gum, butadiene rubber and silicone rubber foaming agent, and closed cell foaming, atmospheric pressure foaming and pressure foaming are applicable. The production process of foaming agent ADC in China mostly adopts chlorine gas oxidation method and sodium chlorate oxidation method, but there are many defects such as high energy consumption, high material consumption and large amount of pollutants. In addition to forming foaming agent ADC, the other products of the new oxidation process of hydrogen peroxide are water, and the hydrogen peroxide is easy to be measured, and there will be no problem of insufficient oxidation or excessive oxidation. The product quality and yield are stable and pollution-free during the process of production. No by-products, good product quality, high output, large amount of gas, no explosion risk and other advantages. On the basis of theoretical analysis and small scale study on the preparation of foaming agent ADC by oxidation of biuret with hydrogen peroxide, the pilot test was carried out in China, and industrialization was realized. The experimental results showed that the optimum technological conditions were as follows: the new iron-based compound was used as cocatalyst, the ratio of reaction liquid to liquid was 1: 2.5, and the molar ratio of raw material (biuret: hydrogen peroxide) was 1: 1.05. The concentration of catalyst is 1.75 g / l, the concentration of cocatalyst is 3.0 g / l, the concentration of acid is 3.5 mol / l, the reaction temperature is 50 鈩

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