| 摘要 |
Solid thermoplastic oxymethylene polymers of 10x/1x melt index ratio from 25 to 90 are prepared by copolymerizing trioxane with a sufficient quantity of a comonomer containing at least two oxygen containing groups, each capable of providing an oxyalkylene group for cross-linking. Specified comonomers are polyepoxides and diformals. 2,2-(trimethylene)-bis-1,3 - dioxolane, monocrotylidene trimethylol-ethane monoepoxide, glutaraldehyde, terephthaldehyde and acrolein dimer. A third comonomer which is a cyclic ether, e.g. ethylene oxide and dioxolane may also be present. Preferred catalysts are boron fluoride and its complexes with a compound in which oxygen or sulphur is the donor atom. Small amounts of a chain transfer agent, e.g. methylol may also be present. |
