Boron catalysts ring-opening polymerization

The polymer can be made into a branch structure by ring-opening polymerizing ethylene imine under an acidic catalyst. Also, a linear polymer can be made by hydrolyzing the poly(N-formylethylene imine) obtained by the ring-opening polymerization of 2-oxazoline with boron trifluoride or sulfuric acid. [Pg.1545]

Obtained by the ethylene oxide ring-opening polymerization using Friedel-Crafts catalysts such as boron trifluoride, tin tetrachloride or zinc chloride, or acid or alkali catalysts. [Pg.1546]

Wolfe and Wagener have developed main-chain boronate polymers (59) (Fig. 38) by the acyclic diene metathesis (ADMET) polymerization of symmetrical ,oj-dienes, containing both methyl- and phenyl-substituted boronate functionalities using Mo and Ru catalysts.84 The ring-opening metathesis polymerization (ROMP) of several norbornene monomers containing methyl- and phenyl-substituted boronates into... [Pg.45]

Polyformaldehyde. Polyformaldehyde or polyacetal is made by two different processes. Delrin is made from formaldehyde by anionic polymerization catalyzed by a tertiary amine. The homopolymer is end-capped with acetic anhydride. Celcon is made from trioxane cationic copolymerization using boron trifluoride catalyst and ethylene oxide (2-3%) as the comonomer. Boron trifluoride is a Lewis acid that associates with trioxane and opens up the six-membered ring. Ethylene oxide provides the end capping. Without an end cap, polyformaldehyde is thermally unstable and loses formaldehyde units. [Pg.98]