Octadecyl Acrylate Can Be Prepared Using Two Esterification Methods
Octadecyl acrylate can be prepared using two esterification methods. Through studying the influencing factors of the esterification reaction, it was found that: (1) toluene was used as a water carrier solvent, with a molar ratio of acrylic acid to octadecanol of 1.2:1.0, p-toluenesulfonic acid of 3.0% (mass fraction), and hydroquinone of 1.0% (mass fraction). The reaction was refluxed at 110-120 ℃ for 8 hours with a yield of over 90%. (2) Without using a water carrying agent, the molar ratio of acrylic acid to octadecanol is 1.2:1.0, p-toluenesulfonic acid is 1.0% (mass fraction), and hydroquinone is 0.5% (mass fraction). The reaction is gradually heated under reflux conditions for 6 hours, and the yield of higher esters is over 90%. The melting point, boiling point, and elemental composition of octadecyl acrylate prepared by two methods were compared and analyzed using infrared spectroscopy and nuclear magnetic resonance spectroscopy, and it was confirmed that there were no significant differences in its structural characteristics. This indicates that the use of melt esterification method to prepare octadecyl acrylate can reduce the amount of catalyst and inhibitor, while ensuring the obtaining of higher purity acrylic acid esters with higher yields. It is an advanced method for efficiently and reliably preparing this type of monomer.
Using octadecyl acrylate monomer as raw material, BPO as initiator, and toluene as solvent, polyacrylic acid octadecyl ester was prepared using microwave technology. Relevant experiments have shown that microwave radiation has shown very good effects in polymer synthesis, and the molecular structure characteristics of the prepared product are not significantly different from those reported in the literature; Under the conditions of microwave power of 195W and radiation time of 15 minutes, the molecular weight (Mw) of the polymer reached 13259, with a relatively narrow molecular weight distribution. Mw/Mn was only 1.50, the characteristic viscosity was 13.2mL · g-1, and the yield was 84.6%. Its production efficiency and energy saving fully reflect the advantages of microwave assisted polymerization.
Studying the properties of single molecule films of octadecyl acrylate, octadecyl polyacrylate, and random copolymers of octadecyl acrylate/vinyl carbazole at the gas-water interface, it was found that both polymer single molecule films have good stability. The use of continuous compression can eliminate the relaxation characteristics of the polymers and obtain tightly arranged single molecule films. Introducing carbazole groups on the molecular chain of octadecyl polyacrylate can significantly improve the transfer properties of monolayers and obtain a novel polymer LB film containing photoelectric functional groups.
