Taddeo Francesco, Vitiello Rosa, Ruocco Michela, Turco Rosa, Russo Vincenzo, Tesser Riccardo, Di Serio Martino
University of Naples Federico II, Department of Chemical Sciences, Complesso Universitario di Monte Sant'Angelo, 80126, Naples, Italy.
Consorzio Interuniversitario per le Reattività Chimiche e la Catalisi, CIRCC, Italy.
Heliyon. 2024 Jun 18;10(12):e33164. doi: 10.1016/j.heliyon.2024.e33164. eCollection 2024 Jun 30.
The production of cementitious formulations involves the addition of chemical additives essential for the optimization of many properties. Superplasticizers are considered additives of great interest but when mixed with concrete they lead to an undesirable increase of air content, with the consequent development of foam. This can adversely affect both mechanical properties and workability, therefore, the use of an antifoam agent is also necessary which should be able to prevent or destroy the foam. This work aims to synthesize esters derived from the reaction of glycine betaine with saturated and unsaturated fatty alcohols of different chain lengths. The reaction products were analyzed by H NMR analysis, and the stability of antifoam agents in a superplasticizer solution was studied through foaming tests according to the Ross-Miles method. At the same time, their effectiveness in the cementitious systems was evaluated through flow Table tests. Finally, the effectiveness of the antifoam agents was quantified through an image analysis software, , which allowed the investigation of the contents of the bubble in concrete samples. All synthesized antifoams showed properties superior to the commercial product, especially defoamers containing saturated fatty alcohols. It has been found that alcohols with too small or too long carbon chains were not effective. In particular, it was verified the optimal range of carbon atoms number contained in the antifoam chain which included between 12 and 14.
水泥基配方的生产涉及添加对优化多种性能至关重要的化学添加剂。高效减水剂被认为是非常有价值的添加剂，但与混凝土混合时会导致含气量意外增加，进而产生泡沫。这会对机械性能和工作性产生不利影响，因此，还需要使用消泡剂，其应能够防止或消除泡沫。这项工作旨在合成由甘氨酸甜菜碱与不同链长的饱和和不饱和脂肪醇反应得到的酯。通过核磁共振氢谱分析对反应产物进行分析，并根据罗斯 - 迈尔斯法通过发泡试验研究消泡剂在高效减水剂溶液中的稳定性。同时，通过流动台试验评估它们在水泥基体系中的有效性。最后，通过图像分析软件对消泡剂的有效性进行量化，该软件可用于研究混凝土样品中的气泡含量。所有合成的消泡剂均表现出优于市售产品的性能，尤其是含有饱和脂肪醇的消泡剂。已发现碳链过短或过长的醇无效。特别是，已验证消泡剂链中所含碳原子数的最佳范围为12至14。
