Synthesis and Characterization of Amino‐Functionalized PDPS/PDMS Copolymers

Various amino‐functionalized polysiloxanes were synthesized in high yields (∼90%) via ring‐opening polymerization of cyclic siloxane monomers through either bulk or solution process. The amino‐functionality was introduced through adding (MeO) 2 MeSiC 3 H 6 NHC 2 H 4 NH 2 (A) or NH 2 C 3 H 6 (Me) 2 SiOSi(Me) 2 ‐C 3 H 6 NH 2 (B) as terminators and/or as reagents mixed with monomers initially. The bulk polymerization of D 4 and P 4 was initiated with potassium salts such as Me 3 SiOK or KOH, while the solution living polymerization of D 3 and P 3 was initiated with LiOH in THF or toluene solution. The optimum conditions for preparing copolymers with different structure types were studied. The purity of the products determined by silica gel column chromatography was found to be higher than 98%. All of the copolymers were characterized with GPC, 1 H NMR, and DSC techniques. The silyl derivatives of primary amines were used in GPC characterization. The number‐average molecular weights determined by 1 H NMR and those determined by GPC measurements were in excellent agreement. The aminosilane A served either as a terminator, which gave an amino‐terminated polysiloxane, or a reagent which was mixed with comonomers initially and incorporated into the copolymerization to give a side‐chain aminopolysiloxane. When A was used as a terminator, no insertion of A into the copolymer was found. In addition, the molecular weights of the copolymers can be controlled by the amount of terminating aminosilanes added into the system.