Polyols for preparing flexible polyurethane foam, and preparation method and application thereof

A method for preparing polyols for making flexible polyurethane foam, characterized by comprising the following steps:

• (1) simultaneously pumping a solution A obtained by dissolving phosphorus oxychloride in an inert solvent and a solution B obtained by dissolving epichlorohydrin and a first acidic catalyst in an inert solvent into a first microchannel reactor of a microchannel reaction device to carry out a reaction, thereby obtaining a chloroalkoxy phosphorus compound;
• (2) simultaneously pumping a solution C obtained by dissolving glycidol and a second acidic catalyst in an inert solvent and the chloroalkoxy phosphorus compound obtained in step (1) into a second microchannel reactor of the microchannel reaction device to carry out a reaction, thereby obtaining a reaction solution containing a hydroxy compound;
• (3) simultaneously pumping a solution D obtained by dissolving epoxy vegetable oil and a basic catalyst in an inert solvent and the hydroxy compound obtained in step (2) into a third microchannel reactor of the microchannel reaction device to carry out a ring-opening reaction, thereby obtaining a vegetable oil polyol;
• and
• (4) simultaneously pumping a solution E obtained by dissolving propylene oxide in an inert solvent and the vegetable oil polyol obtained in step (3) into a fourth microchannel reactor of the microchannel reaction device to carry out an addition polymerization reaction, thereby obtaining the polyols for preparing flexible polyurethane foam.