Orange Wood Fiber Reinforced Polypropylene Composites: Thermal Properties

Abstract

A major drawback of natural-based composites is the incorporation of reinforcements that are less thermally stable than the matrix; therefore, the thermal properties of the resultant composite material needs to be studied. In this work, orange wood fibers were used to reinforce polypropylene. The effects on the thermal properties of the polymeric matrix were analyzed. To this end, differential scanning calorimetry (DSC), thermogravimetry (TGA), thermomechanical analysis (TMA), and dynamic-mechanical analysis (DMA) were performed. It was found that the degradation of the material took place in two distinct phases: the reinforcement, close to 250 °C, and the matrix, above 340 °C. DSC results showed that fiber reinforcement did not influence the transition temperatures of the materials, although it did affect the polymer crystallinity value, increasing by 7% when the composite is reinforced with 50% of the lignocellulosic reinforcement. The coefficient of expansion obtained by TMA indicated that thermal expansion decreased as the amount of reinforcement increased. DMA assays showed that the reinforcement did not modify the glass transition (20 to 25 °C) temperature and confirmed that the addition of reinforcement increased the crystallinity of the product.

Evaluation of Thermal and Thermomechanical Behaviour of Bio-Based Polyamide 11 Based Composites Reinforced with Lignocellulosic Fibres

“…On the other hand, cellulose nanocrystals (CNC) and modified CNC also obtained no significant changes in crystallinity when they were used as reinforcement in PA11 [36]. This is the opposite effect to that observed in other polymer matrices, where the cellulosic fibres acted as nucleating agents, increasing the polymer crystallinity [22,37,38]. Nonetheless, these matrices had weaker interactions with cellulose fibres than PA11.…”

Utilization of Polypropylene Film as an Adhesive to Prepare Formaldehyde-free, Weather-resistant Plywood-like Composites: Process Optimization, Performance Evaluation, and Interface Modification

“…In terms of pyrolysis characteristics, the pyrolysis of wood (such as the eucalyptus wood used in this research) usually occurs above 200 °C (Ma et al 2016), while the pyrolysis of PP usually occurs at higher temperatures than 300 °C (Reixach et al 2015). Therefore, the hot-pressing temperature for wood veneer/PP film composites must be below 200 °C, which was to avoid the pyrolysis of raw materials during hot-pressing.…”

“…According to available reports, 165 to 195 °C is also an acceptable range for preparing PP-based NFRPCs (Zhou et al 2013;Malakani et al 2015;Reixach et al 2015). By contrast, the hot-pressing temperature for preparing conventional plywood using UFR as adhesive is usually approximately 100 °C (Hua 2002;Song et al 2016).…”

Manufacturing and Characterization of Green Composites with Partially Biobased Epoxy Resin and Flaxseed Flour Wastes

“…In this case, it can be seen how the lowest dimensional stability of the developed composites was obtained for composites filled with 10 wt% for both types of filler size, CFF and FFF, with CLTE values of 0.938 and 0.824 µm m −1 K −1 respectively. Despite this slight increase, the dimensional stability of the developed composites was very high compared to conventional WPCs with CLTE values higher than 50 µm m −1 K −1 [71][72][73]. Figure 7 shows the evolution of the water absorption over time for BioEP resin and BioEP/FF composites filled with 10 wt% and 40 wt% of CFF and FFF.…”