Synthesis Of Waterborne Polysiloxaneurethane Nano-Dispersions And Application As Textile Finishing Agent

Textile finishing which focuses on formaldehyde-free and multi-function becomes the hotspot with people's consciousness more and more on environmental protection. Multi-function can be achieved by preparing polysiloxane-polyurethanes which are the perspective finishing agents.Polysiloxaneurethane (PSU) dispersions were prepared with isophorone diisocyanate (IPDI), polypropylene glycol (PPG), hydroxypropyl terminated polydimethylsiloxane (PDPS), dimethylol propionic acid (DMPA) and cationic chain-extender DMDHPPDA synthesized in our Lab. Technological conditions of hydrophilic chain-extenders content, the extent of neutralization and efficiency of stirring were determined, then ratio of isocyanate to polyol and the molecular weight of PPG, PDPS were studied. Series stable WPSU dispersions with PDPS content 0 % -50 % were synthesized with suitable conditions. Samples appeared transparent, average particle size was between 50 nm to 60 nm. Phase transition, average particle size and microcosmic construction of PSU were analyzed with rotational viscosimeter, DLS and FTIR. Change of surface water contact angle of the PSU film was measured by contact angle tester.The prepared PSU dispersions were applied to crease-resistant finishing of cotton. Suitable technological conditions of PSU were determined by studying finishing conditions, PSU structure and its dosage. Finishing results were compared between PSU and etherified 2D resin. The cotton was immersed in finishing solution with PSU dosage of 8 g/L and padded twice, then predried at 90°C for 2 min, curred at 160°C for 1.5 min, the finishing process can elevate the crease recovery angle to 50 %, achieving 213°(unfinished 143°) and cut drown drape coefficient to 31 % of unfinished textile. PSU can also hold the breaking strength retention of 131%. Tested by SEM and XPS, the cotton fiber was found smooth and soft.Comprehensively investigated, PSU is good in crease-resist, pliability, and outstanding in breaking strength retention. The formaldehyde-free, waterborne and environment- friendly characteristics made its future application prosperous.