The Study And Using Of Polyether Modified Polysiloxanes

We traversed siloxane-oxyalkylene copolymers'synthesis in this paper, and application as defoaming. From reaction material, We research low polysiloxanes'synthesis,different polyether; mix-polyeher graft polysiloxanes; lastly mixture as defoaming.In this thesis, low polysiloxanes was synthesized with octamethycycllotetra siloxane and high hydrogen-containing polysiloxanes as materials. As the weight of D4 to UC-202 is 94 to 6, the optimal technology was obtained as follow: reaction temperature is 60℃for 6 h, dosage of chemical which is used for closed end MM is 0.2, dosage of the oil of vitriol is 1.5% of the whole materials. In this thesis, synthesis of Si-O-C defoamer was studied ,its materials are polyhydrosiloxanes and polyoxyalkylene,acid is used for activator. Then the optimal condition is as the following: the mol of polyhydrosiloxanes and polyoxyalkylene is 1 to 15, the dosage of activator is 0.4%, reacting bellow 110℃for 8h, copolymers of Si-O-C polyoxyalkylene is synthesized in the optimal techlonogy. This thesis also introduce sythesis of Si-C defoamer in detail. And their materials are polyhydrosilxanes and polyoxyalkylene, hexachloroplatinic acid is the catalyst and through orthogonal experimental result, the optimal technology is obtained as follow: reaction temperature is 110℃for 8h, the dosage of catalyst is 30ppm, the mol of polyhydrosilxanes and polyoxyalkylene is 1 to 1.5, ratio of translation can reach at 100﹪. Si-C polyoxyalkylene is synthesized in the optimal condition. As the content of hydrogen is 0.18﹪, molecular weight of polyoxyalkylene is 500, the content of EO is 15%, defoamer which is synthesized by polyether copolymer organosilicon has the optimal capability on antifoaming and defoaming.Defoamer which was obtaied by duplicate matches in the experiment is the same capability as products sold in market.