Thermal degradation of a poly(vinyl alcohol) film studied by multivariate curve resolution analysis

A polymer phase diagram showing the thermal degradation of poly(vinyl alcohol) (PVA) is developed by using the multivariable curve resolution (MCR) technique. Observed temperature-dependent infrared spectra are resolved into inherent states corresponding to four transient polymer phases: (i) solid state (crystalline), (ii) rubber state (amorphous), (iii) molten state (fluid), and (iv) thermal degradation product (residues). In comparison with the four pairs of spectral patterns and concentration profiles obtained from MCR outputs, each mixture state reveals a true transient characteristic, and the phases of thermal degradation of PVA can be visualized.