| 摘要 |
Normally solid copolymers contain (a) recurring oxymethylene groups and (b) recurring groups derived from compounds of formula <FORM:1121245/C3/1> and/or of formula <FORM:1121245/C3/2> where R0 is alkylene, arylene or aralkylene, R, R1, R2, R3, R5, R6 and R8 are hydrogen or C1- 5 alkyl, R4 and R7 are C1- 5 alkyl and n is 0, 1, 2 or 3. They have molecular weights of 5000 to 100,000, up to 7% of the comonomer (b) and are obtained by conventional techniques. A third monomer which is a conventional cyclic ether or cyclic acetal may also be incorporated, and either formaldehyde or trioxan may be used to obtain the oxymethylene groups (a). Exemplified copolymers are of trioxane, glyoxal bis - (trimethylolpropane acetal), and optionally 1,3-dioxolan obtained using BF3.(CH3)2O or BF3.(C2H5)2O in cyclohexane.ALSO:Compounds of the formula <FORM:1121245/C2/1> and/or of the formula- <FORM:1121245/C2/2> where R DEG is alkylene, arylene or aralkylene, R1, R2, R3, R5, R6, R8 are hydrogen, R is hydrogen or C1- 5 alkyl and R4 and R7 are C1- 5 alkyl are obtained by reacting the corresponding dialdehyde, diketone or ketoaldehyde with a 1,1,1-trimethylolalkane. In an example, trimethylolpropane is reacted with glyoxal tetrabutylacetal in the presence of p-toluenesulphonic acid to form glyoxal-bis-(trimethylolpropane acetal), a portion of which was then converted into its dimethyl ether by reaction with diazomethane. |
