Study Of Microwave On The Synthesis And Application Of Siloxane-oxyalkylene Copolymer

Siloxane-oxyalkylene copolymer is synthesized by polyoxyalkylene and polyhydrosiloxane via graft reaction.It takes the characters of hydrophilic and permeability of polyether and the character of low surface tension of siloxane together to become an excellent surface agent which are widely used in cosmetics, medical supplies,fabric finishing,Defoamer and many other fields.It is a new force appeared in the family of surfactant.In recent years,many scholars at home and abroad have set off a strong wave in this research area.In this paper,it is first time to prepare the high-performance complex catalyst and to use it in catalytic synthesis of siloxane-oxyalkylene copolymer for exploring a fast and solvent-free technique.The main three research respects of the synthesis and applications of the product in this paper are conducted as follows.1.Catalyst preparationWith the hexachloroplatinic acid and polyoxyalkylene as materials,a high efficiency catalyst is made under microwave heating.The optimal experiment conditions are:microwave power of 119W,radiation time of 10min,volume ratio of hexachorophatinic acid and polyoxyalkylene of 1:10.The translation ratio of polyhydrosiloxanes can achieve 97%with the new prepared catalyst,which is much more than that(85%) of the original catalyst.2.Synthesis of siloxane-oxyalkylene copolymerSiloxane-oxyalkylene copolymer is synthesized without any organic solvent and characterized by IR.Through the investigations of the effects of microwave power, radiation time,catalyst dosage and ratio of reactants on the product,the optimal experimental conditions are determined as follows:the dosage of Pt is 1.5×10^-4% (the mass content of effective component of Pt),the microwave power is 280W,the radiation time is 25min,the mole ratio of polyoxyalkylene to polyhydrosiloxane is 1.2:1.0.3.Application of siloxane-oxyalkylene copolymer The Siloxane-oxyalkylene copolymer is used to prepare Defoamer compound due to its good surface activity and emulsification.In this thesis,the Defoamer compound prepared is very effective at foam killing and control and displays an excellent stability even at high temperature.The optimal compositions of the Defoamer compound are determined to be:65%of Siloxane-oxyalkylene copolymer,14%of self-prepared silica ointment,15%of polyoxyalkylene,5%of polysiloxane and 0.5% of both liquid olefin and CMC.The results of all the experimental data show the Defamer's application foreground will be bright.