Desorption Behavior and Thermogravimetric Analysis of Bio-Hardeners

In this work, the thermal degradation and drying of bio-hardeners are investigated. Four bio-hardeners based on exudates of Senegalia senegal, Vachellia nilotica, Vachellia seyal, and Acacia Siebteriana were analyzed by FTIR and thermogravimetric analysis, and a desorption study was also conducted. The analysis by infrared spectroscopy indicates the existence of oligomers of different types all giving 5-hydroxy-2-hydroxymethylfuran and 2, 5-dihydroxymethylfuran which are then the real hardening molecules. The pyrolysis of these extracts reveals three main regions of mass loss, a first region is located between 25 degrees C and 110 degrees C reflecting the loss of water from the adhesive and the formation of some traces of volatile organic compounds such as CO2 and CO, a second zone characterized by the release of CO, CO2 and CH4 gases with peaks between 110 degrees and 798.8 degrees C. At the end of the analysis, about 22% of the initial mass remains undecomposed, this mass corresponds to the rigid segments of the bio-hardener which are not completely decomposed

Characterisation of a composite material with polyester matrix reinforced with particles from doum palm (hyphaene thebaica) fruit

The objective of this paper is to extract the hulls of Hyphaene thebaica fruit to elaborate a composite material with polyester matrix and to characterize it physically and mechanically. The first step of the process consisted of crushing, drying and then physically characterizing the hulls. The obtained results show that the average density is 766 kg/m3, the kinetic of water absorption is 40.39% and the average kinetic of humidity is 9.23%. The second step of the process consisted of crushing and sieving the hulls in order to classify them in four different sizes, and then proceeding to the manufacture of panels according to the different sizes of particles and different dosages. Another phase of characterisation has thus been achieved and the following results have been obtained: general theoretical density is 1275.86 kg/m3; average apparent density is 0.892 g/cm3, and the average density of the shells is 0.766 g/cm3. The average porosity rate obtained is 0.3%. As for the mechanical characteristics obtained by the three-point bending, the results on the average flexural modulus of elasticity (MOE) are presented as follows: 3400 ± 511 MPa for 10%–90% and size 0.5–2.5 mm, 4100± 320 MPa for 15%–85% size less than 0.5 mm; 5730± 212 MPa for 30%–70% size 0.5–2.5 mm; 6510± 211 MPa for 15%–85% size 0.5–2.5 mm; 5880± 110 MPa for 30%–70% size less than 0.5 mm. The corresponding flexural breaking strength (MOR) are respectively: 12.8± 0.2 MPa; 13.5± 0.2 MPa; 12.0± 0.5 MPa; 10.8± 0.2 MPa and 13.8± 0.3 MPa. The methods used in this work are experimental. These results allowed to deduce that the composites elaborated are particleboard type P2 and have the advantage to be used as panels useable in furniture, thermal and acoustic insulation and as structural materials. Thus, it is also possible to use it as an abrasive aggregate for sanding. All prepared particleboards had exterior and interior quality capabilities, for both working and non-working environments. It is also possible to use it as an abrasive aggregate for sanding