CRYOCOPOLYMERIZATION OF HYDROGEN-CYANIDE WITH ACETALDEHYDE

Calorimetric technique was used to study in detail the phase state of the ''HCN-acetaldehyde'' system. The initiation of copolymerization oc curs throughout the whole range of initial concentrations of monomers in the process of defrosting the system radiolyzed at 77 k in the regi ons of enhanced molecular mobility (premelting or glass softening). Th e HCN component in the copolymer monotonously increases with an increa se in the concentration of this comonomer in the starting mixture. The copolymer contains an insoluble fraction. The system passes completel y to a glassy state with approximate to 25% molar of HCN. The complete ly soluble copolymer is formed only if the process is carried out in t he system of this kind. The copolymerization in the glassy system occu rs by cationic and radical mechanisms. With small doses of preirradiat ion, the copolymer is formed mainly by the cationic mechanism. With an increase of the irradiation dose, the HCN concentration in the copoly mer is increased. The forming copolymer is much more thermostable than polyacetaldehyde prepared under the same conditions.