The preparation and acid‐catalyzed hydrolysis of polyoxymethylene isopropyl methyl ethers

The first four members of the polyoxymethylene ether series (CH 3 ) 2 CHO(CH 2 O) n CH 3 were prepared, separated by fractional distillation and GLC, and characterized by NMR. Rate constants for the aqueous acid hydrolysis of the compounds were determined at 25°, 30°, and 35°C. Although the polyformals ( n > 1) in this series hydrolyzed at essentially the same rate, they all hydrolyzed three times faster than the formal ( n = 1). It is proposed that a mixed polyformal, (CH 3 ) 2 CHO (CH 2 O) n >1 CH 3 , undergoes two concurrent fissions to yield (1) the stem (CH 3 ) 2 CHOCH 2 with CH 3 O(CH 2 O) n −1 as the leaving group and (2) the stem CH 3 OCH 2 with (CH 3 ) 2 CHO(CH 2 O) n −1 as the leaving group. Most of the fissions occur by the first path. An equation that can aid in predicting the rate of hydrolysis of a mixed polyformal was developed and tested.