Effects of butynediol alkoxylate trisiloxane on the surface activity, wetting, and foam properties of polyether trisiloxane

Foam control of polyether trisiloxane (PTS) superspreader solutions with a traditional defoamer, such as silica-filled polydimethylsiloxane, is weak or even ineffective, which represents a problem that needs to be solved. In this paper, we describe a new foam control method for PTS by blending this superspreader with low foaming butynediol alkoxylate trisiloxane (TBEO). TBEO can be dissolved in PTS, acting as a foam control agent. The two components were pre-blended in different proportions (10–90% PTS-TBEO) before dilution. Performance tests of PTS-TBEO were conducted by measuring the equilibrium surface tension, dynamic surface tension, wettability, foam morphology, and foam stability. It was found that the addition of TBEO had an insignificant effect on the equilibrium and dynamic surface tension of the PTS foaming system. In addition, with an increase in the proportion of TBEO, the spreading speed of the mixture aqueous solution at different hydrophobic interfaces slows down, but the change at a low proportion of TBEO (10–40%) is negligible. However, the introduction of TBEO with different proportions will cause the originally stable foam to show different degrees of “cliff-like” decline, and with the increase of TBEO proportion, the relative antifoam efficiency also increases. And from the perspective of the interaction between TBEO molecules and the foam liquid film, the mechanism of TBEO in suppressing foam height of PTS superspreader solution was further explored. • The foam performance of polyether trisiloxane (PTS) can be effectively controlled by introducing TBEO. • A TBEO/PTS mixture still has high surface activity and strong surface wettability. • TBEO can enter the liquid film through bridging, thereby reducing foam stability.