A side amino polysiloxane-modified
polyurethane coating agent is disclosed. Side aminopolysiloxane (SAPDMS),
polytetrahydrofuran glycol and
polyethylene glycol as mixed soft segments, dimethylol propionic acid as a hydrophilic chain
extender, and 1,4-
butanediol as a hard segment
regulator are reacted with
isophorone diisocyanate to synthesize a waterborne
silicone modified
polyurethane (WSSPU), and the waterproof and
moisture-permeable fabric
coating agent is prepared based on the WSSPU. The composition and
microstructure of a WSSPU film can be characterized by an
infrared spectroscopy, a differential scanning
calorimeter, a dynamic mechanical analyzer, a
positron annihilation lifetime
spectroscopy, and the like. The mechanical properties of the WSSPU film and the waterproof and
moisture-permeable properties of a coated fabric are investigated. Results show that a stable
emulsion can be obtained when the dosage of the side aminopolysiloxane (
mass ratio) is less than 15%. After polysiloxane modification, the internal micro-phase separation structure of the film is more obvious, the free volume cavity becomes larger, and the
moisture-permeable properties are improved.