The Synthesis Of Nucleating Agents NA-11 And NA-21 Of Polypropylene

In this thesis, the nucleating agents NA-11 and NA-21 for polypropylene were prepared by condensation of 2,4-bis-tert-butylphenol and formaldehyde, esterification, hydrolysis and neutralization reactions.In the condensation reaction, the factors affecting the yield and quality of 2,2'-methylene-bis(4,6-ditertbutylphenol), such as the choice and dosage of condensation agent, catalyst and emulsifying agent, reaction temperature, reaction time and treatment method etc. were investigated through single factor experiments and the optimum experimental conditions were gained. Under the optimum conditions, the yield of the intermediate was 97.2% base on 2,4-bis-tert-butylphenol and the melting point was 147.8℃.In esterification reaction, 2,2'-methylene-bis(4,6-ditertbutylphenol) phosphate was synthesized in cyclohexane as solvent. The optimal condition of reaction was determined. In this conditions, the yield of the phosphate was 76.1% based on 2,2'-methylene-bis(4,6-ditertbutyl phenol) and the melting point was 342.14℃.The paper tried to synthesize phosphate in polar solvents (acetonitrile, pyridine), which is different from previous methods. The results showed that this method was possible and the yield of phosphate reached 90.5% and 98.7% based on 2,2'-methylene-bis(4,6-ditertbutylphenol), respectively.In neutralization reaction, the results were as follows: the yield of the product is 83.2% based on 2,2'-methylene-bis(4,6-ditertbutylphenol) phosphate under the reaction conditions of the suitable amount of phosphate of 8g in 50mL 95% ethanol and the theoretical amount of sodium hydroxide;the yield of the product is 72.0% under the reaction condition of the suitable amount of phosphate of 8g in 50mL absolute ethyl alcohol and the theoretical amount of sodium hydroxide, which is lower than the above evidently. A new method for synthesizing NA-11 from phosphate was proposed based on numerous literature and experiments, which was used H₂O as solvent. As a result, the yield of the product increased remarkably to 97.7% based on 2,2'-methylene-bis(4,6-ditertbutylphenol) phosphate.The applying experiments indicated that the quality of NA-11 product reached the level of Asahi Denka's.NA-21 was prepared from NA-11. From the experimental results we concluded that the molar ratio of AlGbto NA-11, dropping temperature, methanol dosage were 1:2, 40°C, 54mL, respectively. The yield of NA-21 was 97.1% based on NA-11 under the above conditions and the melting point was 217.5°C.Furthermore, a new method of preparing NA-21 from phosphate was initiated. It was found that the suitable molar ratio of phosphate, sodium hydroxide to AICI3 was 1:1:0.5 when methanol was the solvent. Under the optimal condition the yield of NA-21 was 95.3% based on 2,2'-methylene-bis(4,6-ditertbutylphenol) phosphate and the melting point was 200.5 °C . Compared to the above means, this method was more convenient.