Poly ether polyols fabrication

Figure 4.33 General technological flow for poly ether polyol fabrication by anionic...

In Chapter 3, the chemistry and technology of the most important oligo-polyols used for elastic polyurethanes fabrication, in fact high MW oligomers (2000-12000 daltons) with terminal hydroxyl groups and low functionality (2-4 hydroxyl groups/mol) were discussed. Polyalkylene oxide polyols (homopolymers of PO or copolymers PO - EO, random or block copolymers), polytetrahydrofuran polyols, filled polyols (graft poly ether polyols, poly Harnstoff dispersion - polyurea dispersions (PHD) and polyisocyanate poly addition (PIPA) polyols), polybutadiene polyols and polysiloxane polyols were all discussed. The elastic polyurethanes represent around 72% of the total polyurethanes produced worldwide. 

Figure 4.30 Scheme for polyether polyol fabrication by anionic polymerisation of alkylene oxides, initiated by glycerol or diols (variant). 1 - Reactor for potassium glycerolate synthesis 2 - Reactor for prepolyether synthesis 3 - Reactor for polyether synthesis 4 - Reactor for purification 5 - Filter press 6 - Storage tank for final purified poly ether 7 - Heat exchangers for removal of the reaction heat 8 - Condensers 9 - Vacuum pumps 10 - Vessels for distilled water 11 - Recirculation pumps 12 - Gear pump or screw (or double screw) pump... 

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