Heterogeneous media, polycondensation

Polyoxymethylene is prepared by the polymerization of anhydrous formaldehyde (see Example 3.22) or of 1,3,5-trioxane (see Example 3.24). Paraformaldehyde, obtained by polycondensation of formaldehyde hydrate, cannot be acetylated in heterogeneous medium. Acetic anhydride and fV,fV-dimethylcyclohexylamine are carefully fractionated and sodium acetate is dehydrated by heating. 

Heterogeneous liquid medium. Heterogeneous aqueous media (gels) are the most used for the synthesis of oxide or sulfide type molecular sieves with T elements in tetrahedral coordination. These solids ciystallize through polycondensation reactions according to ... 

Hence, the performed brief analysis allows to link macromolecular coil structure and reactive medium heterogeneity degree for process of polycondensation in solutioa In its turn, this intercommunication knowledge and the abihty to check... 

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