On the fracture mechanism of a symmetric interface of glassy poly(methyl methacrylate) self-healed at a temperature well below the bulk glass transition temperature

Attenuated total reflection Fourier-transformed infrared spectroscopy (ATR-FTIR) has been used for the elucidation of the molecular mechanism of fracture of weak polymer−polymer interfaces self-healed partially at a temperature ( T ) well below the bulk glass transition temperature ( T g bulk ). For this purpose, a symmetric interface of the carbon-chain polymer such as poly(methyl methacrylate) (PMMA) has been used. It has been found that the integral intensity and the half-width of the band ν = 1725 cm −1 for the fractured PMMA−PMMA interface self-healed at T = 64 °С, i.e. at T = T g bulk – 45 °С, are higher as compared to those for the original PMMA surface and for the PMMA surface annealed at T = T g bulk − 45 °С. The difference found is assigned to the chain scission of interdiffused PMMA chains resulting in the creation of new chain ends and their following oxidation.