摘要:
Block polymers containing poly(tetramethylene oxide) as one of their constituent blocks and a random copolymer of tetrahydrofuran and one or more alkylene oxides as one or more of the other constituent blocks are useful in preparing polyurethanes and polyesters.
摘要:
The resistance to degradation on exposure to high temperatures, water and organic liquids of a polyurethane prepared by reacting a tetrahydrofuran/alkylene oxide polymerizate, an organic polyisocyanate and a chain extender is significantly improved by using a tetrahydrofuran/alkylene oxide polymerizate which contains no more than about 3%, by weight, of oligomeric cyclic ethers.
摘要:
The oligomeric cyclic ether content of a tetrahydrofuran/alkylene oxide polymerizate is significantly reduced by bringing the polymerizate into contact at elevated temperatures with an ion exchange resin bearing -SO.sub.3 H groups.
摘要:
Polymeric carbonate diols are prepared by coupling segments of copolyether glycols with a dialkyl carbonate, with a cyclic carbonate, or with phosgene.The carbonate diols are useful in preparing polyurethanes.
摘要:
Copolyether glycols are modified so that they contain 1-25%, by weight of .beta.,.beta.'-dihydroxyalkyl sulfide moieties.These modified copolyether glycols have enhanced resistance to degradation by heat and oxygen.The invention also relates to a method of making the modified copolyether glycols, to their use as stabilizers against the degradation of the polyether chains, and to polyurethanes made with them.
摘要:
Polytetramethylene ether glycol is modified so that it contains 1-25%, by weight of .beta.,.beta.'-dihydroxyalkyl sulfide moieties.These modified polytetramethylene ether glycols have enhanced resistance to degradation by heat and oxygen.The invention also relates to a method of making the modified PTMEG's, to their use as stabilizers against the degradation of the polyether chain, and to polyurethanes made with them.
摘要:
Tetrahydrofuran/alkylene oxide polymerizates containing no more than 3%, by weight, of oligomeric cyclic ethers are prepared by extracting the ethers from a raw polymerizate with water.
摘要:
Block polymers containing an hydroxyalkyl phthalate ester as one of the constituent blocks and a copolymer of tetrahydrofuran and one or more alkylene oxides as one or more of the other constituent blocks are useful in preparing polyurethanes and polyesters.
摘要:
Block polymers containing hydroquinone di-(.beta.-hydroxyethyl) ether or one of its isomers or homologs as one of the constitutent blocks and a random copolymer of tetrahydrofuran and one or more alkylene oxides as one or more of the other constituent blocks are useful in preparing polyurethanes and polyesters.
摘要:
Esters of poly(tetramethylene ether) glycol are prepared by polymerizing tetrahydrofuran in a reaction mixture which contains, in addition to the tetrahydrofuran, and acylium ion precursor such as acetic anhydride, a polymeric catalyst which contains sulfonic acid groups and, optionally, a carboxylic acid such as acetic acid.