Synthesis of poly(dimethylsiloxane) oligomers with pendant amine groups via co‐equilibration anionic polymerization reactions

Abstract

The present study describes a method of incorporating amine functional groups on poly(dimethylsiloxane) chains as pendant groups on silicon atoms. This method allows for independent control of the molecular weight and the amine content of the oligomer. The new molecular design was achieved by co‐equilibration of the cyclic tetramer octamethylcyclotetrasiloxane (D4) with a new cyclic siloxane monomer containing aliphatic amine substituents on the silicon atoms. The co‐equilibration of the two cyclic siloxanes was carried out in the presence of a silanolate catalyst, using the nonfunctionalized hexamethyldisiloxane as the end‐capper. The distribution of the molecular species at thermodynamic equilibrium and the efficiency of incorporation of siloxane units containing pendant amine functionalities into the poly(dimethylsiloxane) chains were investigated as a function of oligomer chemical composition and molecular weight.

Mechanical and surface properties of polysulfide‐based polyurea modified with aminoethylaminopropyl poly(dimethylsiloxane)

“…The AEAPS used in this modification was synthesized according to a procedure described previously 14,15 (the average amine content was 0.5 mmol/g of siloxane, and the number-average molecular weight was 3700). IPDI (supplied by Crendva Speziaichemie, Germany) was used without purification.…”

Microstructure of the Copolymer Chain Generated by Anionic Ring-Opening Polymerization of a Model Cyclotrisiloxane with Mixed Siloxane Units

“…There are three general routes to siloxane−siloxane copolymers based on the ring-opening polymerization. The equilibrium copolymerization, often referred to as coequilibration, is the most commonly used route. − This process produces copolymers with a random 6 or nearly random 1 distribution of siloxane units, obeying Bernoulli statistics. The copolymerization leads to a considerable amount of cyclic oligomers, particularly, if substituents at silicon are bulky or polar, , or if the process is carried out in solution.…”

Synthesis and properties of polyurethane modified with an aminoethylaminopropyl-substituted polydimethylsiloxane. II. Waterborne polyurethanes

“…7,11 Triethylamine (TEA) and the solvents used in the titrations were dried over 3-Å molecular sieves before use. TDI was degassed and purified by vacuum distillation.…”