초록 ▼

ABA triblock and AnB star polymers are produced by sequential cationic polymerization of 4 and 5 member ring cyclic ethers to initially form a B block and subsequent cationic polymerization of 4 and 5 member ring cyclic ethers to form A blocks at the termini of the B block. The B block is grown from

ABA triblock and AnB star polymers are produced by sequential cationic polymerization of 4 and 5 member ring cyclic ethers to initially form a B block and subsequent cationic polymerization of 4 and 5 member ring cyclic ethers to form A blocks at the termini of the B block. The B block is grown from the hydroxyl groups of a polyol having two or more hydroxyl groups, resulting in a B block having terminal hydroxyl functionality of two or greater. In growing each of the B and A blocks, the acid catalyst is used at a molar ratio relative to hydroxyl groups of the polyol initiator of between about 0.05:1 and about 0.5:1.

대표청구항 ▼

A method of forming an ABA triblock polymer or an AnB star polymer comprising (1) polymerizing a cyclic ether monomer or monomers having 4 to 5 atoms in the cyclic ring from the hydroxyl groups of an alcohol having two or more hydroxyl groups in the presence of an acid catalyst that promotes cationi

A method of forming an ABA triblock polymer or an AnB star polymer comprising (1) polymerizing a cyclic ether monomer or monomers having 4 to 5 atoms in the cyclic ring from the hydroxyl groups of an alcohol having two or more hydroxyl groups in the presence of an acid catalyst that promotes cationic polymerization of cyclic ether monomers so as to produce a B block polymer having terminal hydroxyl functionality substantially equivalent to the hydroxyl functionality of said alcohol, and (2) polymerizing a different cyclic ether monomer or monomers or different combination of cyclic ether monomers, having 4 or 5 atoms in the cyclic rings, from said terminal hydroxyl groups of said B block polymer in the presence of an acid catalyst that promotes cationic polymerization of cyclic ether monomers so as to produce polymeric A blocks at the ends of said B block, the improvement comprising, in each of steps 1 and 2, said catalyst being provided in an amount such that if said acid catalyst is a Lewis acid, the molar ratio of acid catalyst to hydroxyl group(s) on said alcohol is between about 0.05:1 and about 0.5:1, and if said acid catalyst is a proton acid, the molar ratio of hydrogen ions releasable from said acid to hydroxyl group(s) of said alcohol is from about 0.05:1 and about 0.5:1.