The Si-c Polyurethane Foam Stabilizer Synthesis

Foam stabilizer is one of the necessary materials in the foaming process of polyurethane foams. A practical and economical process has been studied in this paper as follows: Polyhydrosiloxane is synthesized with octamethylcyclotetrasiloxane(D4) and high hydrogen- containing polyhydrosiloxane as materials. Then the product is manufactured by the hydrosilylation of polyhydrosiloxane and polyether terminated with alkyl group or ester group. The systemic research focused on the relationship between the structure and the function has been completed by foaming with foam stabilizers of different structures. The influence of process on structure is found.The mathematic model for expressing macro-kinetics of bulk polymerization of polyhydrosiloxane is established in this paper as following:[Dsum]t = [Dsum]eq + ([D4]0-[D4]eq)exp(-kp.4[P*]t)-[Dx]eqexp(-kp.x [P*]t)The kinetic parameters have conic relationship with designed hydrogen-containing and the concentration of catalyst.The cross-linking polymer in foam stabilizer has ill influence on foaming function. The cross-linking polymer is formed through polymerization of polyhydrosiloxane. Polyhydrosiloxane with high hydrogen-containing and high molecular weight tends to produce cross-linking polymer. The number of cross-linking polymer could be reduced., and even be zeroed through appropriate process of the synthesis of poly drosiloxane and hydrosilylation of polyhydrosiloxane and polyether.The structures of foam stabilizer determine its functions. Foam stabilizers with higher hydrogen-containing perform worse. Foam stabilizers with higher molecular weight perform better generally. The end groups of polyether also play an important role. A mixture of foam stabilizers of different structures should be used to obtain better foaming function.The foam stabilizer obtained through the research of this paper exhibits good activity and could be used widely.