Global Journal of Researches in Engineering, J: General Engineering, Volume 22 Issue 1

lobal Journal of Researches in Engineering ( ) Volume XxXII Issue I Version I J G 12 Year 2022 © 2022 Global Journals iii. DSC curves of the analyzed tubes We obtain from Figure 7 for all materials the classical domains for a PVC [14] namely: the wet domain sanctioned by its moisture content (Th), followed by the glassy domain at temperatures below the glass transition (Tg); the rubbery domain, between Tg and cold crystallization (Tcf), the semi-crystalline domain between cold crystallization and melting (Tf). The molten liquid domain (Tlf) and finally the ash domain (Tce). We observe, confused with the glass transition, a fine endothermic peak reflecting a phenomenon called enthalpic relaxation [16]. Cold crystallization is a typical phenomenon of high molecular weight polymers. During the cooling of the molten (liquid) polymer, the latter, because of its high molar masses and the great length of its macromolecular chains, does not manage to crystallize. The liquid polymer then freezes in a disordered state which is the glassy state. When this amorphous polymer is heated, its chains start to vibrate and eventually acquire enough energy to start moving and eventually, after the passage of the glassy transition, adopt positions favorable enough to crystallize before passing to the ash state. This phenomenon has been observed in the literature [14,16, 17] , and then argued in work based on PVC thermogravimetry [18]. TG curves of the analyzed tubes From figure 8, we obtain for all materials that: The dehydration starts around 30 °C and ends at the temperature Th and leads to a loss of mass Mh. it is the disappearance of free water (H2O). The dehydrochlorination begins towards the temperature THCl by losing a mass MHCl. This phase corresponds to the disappearance of HCl and polyene structures, and the possible formation of benzene, naphthalene and phenanthrene. -20 0 20 40 60 80 100 120 140 160 0 200 400 600 800 HDSC (µv) Temperature (°C) DSC thermograms of unloaded PVC tubes and loaded PVC tubes with palm kernel shells. DSC of F0 tubes DSC of F12.54 tubes DSC of F32.01 tubes DSC of F51.02 tubes enthalpic relaxation -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 0 100 200 300 400 500 600 700 800 Mass loss of the tubes (%) Temperatures (°C) TG thermograms of unloaded PVC tubes and loaded PVC tubes with palm kernel shells. TG of F0 tubes TG of F12.54 tubes TG of F32.01 tubes TG of F51.02 tubes Mathematical Models for the Calculation of the Thermal Properties of PVCs as a Function of Dosage with the Load of Palm Kernel Shell Powder from the Results of Experimental Practice Figure 7: DSC thermograms of the elaborated tubes. Figure 8: TG thermograms of elaborated tubes. iv.