Characterization of Commercial Polyvinylbutyrals

Several analyses have been carried out to thoroughly characterize five commercial polyvinyl butyral films supplied by various manufacturers. Model compounds (PVB and plasticizers) having the highest purity available were also used as reference. FT-IR and ¹H- and ¹³C-NMR spectroscopy were used to ascertain the structure of the investigated ter-polymer, as well that of the incorporated additives (mainly the plasticizer). The ratio between these components was also determined. The chemical compositions of these PVBs were similar, and two different plasticizers were identified. The glass transition temperature (T _g ) was deduced from dynamic mechanical analyses (DMA) and found to be very similar for all the investigated films. Size exclusion chromatography (SEC) was also used to study the molecular weight distribution. The analyses were performed using several detectors, and they revealed that PVBs presented similar distributions with molecular weights ranging from 250,000 to 300,000 g/mol.