The molecular-topological structure and thermal stability of Ftorplast F-2M polyvinylidene fluoride irradiated with 1-MeV protons

Pelletized polyvinylidene fluoride (PVDF) of the Ftorplast F-2M brand is a semicrystalline diblock polymer, and its topological structure remains almost unchanged after bombardment with 5 x 10(14) proton/cm(2). The glass transition temperature of the irradiated polymer is reduced by 2A degrees C, but the melting point of the crystalline polymorph and the flow temperature of the polymer significantly increase (from 35 to 137A degrees C and from 132 to 151A degrees C, respectively); the mass fraction of the crystalline modification also increases (from 0.12 to 0.70). As a result of fluorine abstraction by fast protons to form HF, the fluorine content of the polymer decreases and the carbon content increases. The irradiation has no substantial effect on the onset temperature of intense gas evolution or the composition of the gas released during heating the polymer to 300A degrees C.