There are provided new moldable blends of a normally crystalline acetal polymer and a normally non-crystalline elastomeric copolymer of about 15 to 45 mol %, preferably about 25 to 35 mol % of trioxane, about 55 to 85 %, preferably about 65 to 75 mol % of 1,3-dioxolane, said mol percents based on the total of trioxane and 1,3-dioxolane, and about 0.005 to 0.15 wt. %, preferably about 0.05 to 0.12 wt. % of 1,4-butanediol diglycidyl ether or butadiene diepoxide as a bifunctional monomer, based on the total weight of copolymer.