In the last decades, the growing environmental awareness has resulted in a renewed interest in the use of natural materials for different applications. In this context, the use of wood in plastic to obtain composites has grown significantly. In the present work, heartwood and sapwood from Angelim Pedra (Hymenolobiun petraeum) were used to prepare PVC/wood composites. To study the composites with different wood types and filler contents the molecular dynamic was investigated through low field NMR by poton spin-lattice relaxation time measurements (T 1 H) and the thermal behavior was characterized by means of differential scanning calorimetry (DSC) focusing the glass transition temperature and thermogravimetric analyses (TGA) observing the changes in the thermal stability. It was found that increasing addition of wood flour (sapwood and heartwood) caused a small but progressive improvement of the decomposition temperature of the composites, whereas the glass transition temperature remains practically unchanged. In the molecular dynamic behavior, a gradual decrease in T 1 H values was observed with increasing sapwood and heartwood content, indicating that the composites became less rigid. The distribution curves of the domains showed a better interaction and phase dispersion between the composite components with higher filler content.

The focus of this work was to characterize the molecular dynamic of High Impact Polystyrene (HIPS -5% PB), wood -A (Vochysia divergens) and B (Erisma uncinatum) -and their composites, using solid state nuclear magnetic resonance (NMR), by measuring the proton spin-lattice relaxation time (T 1 H) using a low field NMR, and by thermal analysis as Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). DSC and TGA measurements show that both woods present the same molecular behavior. On the other hand, the spin-lattice relaxation time observed that the water is interfering in the packing and arrangements of cellulose chains due to inter and intra hydrogen molecular interactions, promoting the T 1 H values changed to high values. T 1 H shows that the sample B presents a higher rigidity than sample A. However, HIPS presents higher T 1 H values comparing to wood types. Analyzing the relaxation data for the composites, the values indicate that composites present an interaction between both components.