Synthesis, solvent interactions and Hansen solubility parameters of polyvinyl butyral

In this work, polyvinyl butyral (PVB) with number-average molecular weight of 35,700 g mol −1 and butyraldehyde content of 78.66% was synthesized, and was characterized by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), derivative thermogravimetric analysis (DTG) and pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS). The results showed that the prepared PVB has high degree of acetalization and high thermal stability. Hansen solubility parameters (HSPs) of PVB were determined by HSPiP software, turbidimetric titration, intrinsic viscosity method and group contribution method. The Flory–Huggins interaction parameters ( χ and χ HSP ) between PVB and solvents were calculated, and the results showed that the intrinsic viscosity [ η ] increased linearly with the decrease of χ and χ HSP values. Both the graph of [ η ] versus χ and the graph of [ η ] versus χ HSP can be divided into dissolving area and nondissolving area by χ = 0.5 and χ HSP = 0.5, which fully proved that the HSPs obtained in this paper were convincing. It is expected that these parameters are available for predicting the solubility of PVB in various solvents and the compatibility with additives.