.alpha.-Poly(oxymethylene) 1,3,5-Trioxane, homopolymer 9002-81-7 FORMALDEHYDE Formaldehyde polymer Formaldehyde, homopolymer NSC28424 Paraformaldehyde Poly(oxymethylene) Poly-s-trioxane Polyformaldehyde Polytrioxane Takafest s-Trioxane, polymers