GB1147791A - Polyethers - Google Patents

Abstract

1,147,791. Polymers of trans-2,3-butylene oxide; polyurethenes. IMPERIAL CHEMICAL INDUSTRIES Ltd. 5 Aug., 1966 [16 Aug., 1965], No. 34921/65. Headings C3C and C3R. Partially crystalline polymers of trans-2,3- butylene oxide having at least 80% hydroxyl end groups and molecular weights in the range of from 300 to 3000 are prepared by polymerizing trans-2,3-butylene oxide in the presence of an acidic catalyst, which may be a protonic acid, such as sulphuric, fluorosulphonic or perchloric acid, or a Lewis acid, such as boron trifluoride or its addition products or aluminium chloride, the latter being used together with a co-catalyst that is water or a polyhydroxy compound, such as a glycol. One or more other alkylene oxides, such as propylene oxide, 1,2- butylene oxide and cis-2,3-butylene oxide, may optionally be copolymerized with the trans- 2-3-butylene oxide in a random or block form, but the trans-2,3-butylene oxide preferably constitutes at least 25%, on a molar basis, of the total oxides used. After polymerization the catalyst residues can be removed from the polyether by washing with an aqueous solution or suspension of an alkaline material or by treating with active carbon or absorbent earth. An antioxidant, such as a sterically hindered phenol, may be incorporated in the polyether during manufacture or purification. The polyethers may be reacted with organic polyisocyanates to form polyurethanes, optionally in the presence of gas-generating agents such as water or inert liquids of low boiling point. Catalysts, e.g. tertiary amines and organo-metallic compounds, and surface active agents, e.g. siloxane polymers and siloxane-oxyalkylene block copolymers may optionally be added to the reaction mixture.