季戊四醇二丙烯酸酯的合成和表征

Synthesis and characterization of pentaerythritol diacrylate

丙烯酸盐灌浆材料由于具有粘度低、流动性好、能灌入细微裂缝等优点,已被广泛应用于混凝土工程中的帷幕防渗和裂缝修补。常用丙烯酸盐灌浆材料采用酰胺类交联剂,具有一定毒性。使用非酰胺类交联剂进行替代,可以降低灌浆材料毒性,扩大其使用范围。以季戊四醇和丙烯酸为原料,采用直接酯化法合成出丙烯酸盐交联剂季戊四醇二丙烯酸酯,并探讨了催化剂用量、酸醇摩尔比和反应时间对产物产率的影响,得出最佳的合成条件。合成季戊四醇二丙烯酸酯的最佳反应条件为:催化剂用量为反应体系总质量的2.0%,酸醇摩尔比为2.6,反应温度为105～115℃,反应时间为4小时,产率为58%。产物利用红外光谱和核磁共振谱进行了表征。使用该交联剂制备化学灌浆材料,用于磷石膏的浇筑固化,可大幅度降低磷石膏堆存成本,提高磷石膏堆存的安全性。

@@@@Acrylate chemical grouting materials are widely applied in seepage proof curtain and crevice repair in concrete work because of its advantages such as low viscosity, good fluidity, and excellent injection capability for tiny cracks. However, most of the commercial products of acrylate grouting material use amide-containing cross-linking agent and have certain toxicities. Non-amide cross-linking agent can be used to lower the toxicity and to extend the application of these grouting materials. Starting from pentaerythritol and acrylic acid, the cross-linking agent pentaerythritol diacrylate was synthesized through direct esterification. The influencing effects on the product yield, such as catalyst content, acid/alcohol ratio, and reaction time, were investigated, in order to optimize the esterification reaction. The optimal conditions for pentaerythritol diacrylate are as follows: the catalyst content is 2.0% in weight of the total reaction mixture, the mole ratio of acrylic acid/pentaerythritol is 2.6, the reaction temperature is 105~115°C, the reaction time is 4 h, and the yield is about 58%. The product was characterized by IR and 1H NMR spectra to confirm the molecular structure. The obtained cross-linking agent can be used to prepare chemical grouting materials, which will be subsequently applied in the casting solidification of phosphogypsum. This chemical grouting strategy is expected to decrease the cost and increase the safety of the phosphogypsum stacking.