where ΔHc is PLA’s enthalpy of cold crystallization, ΔHm is the enthalpy of melting of PLA, and ΔHm100% is the theoretical melting enthalpy of 100% crystalline PLA, 93 J/g [Puchalski ET AL., 2017]. Scanning electron microscopy (SEM) analysis was performed on samples sputter-coated with gold and examined using a Hitachi TM3030Plus SEM (15 kV, high vacuum). Backscattered electron imaging provided elemental contrast. Tensile properties, including maximum strength, elastic modulus, and elongation at break, were evaluated following ASTM D638 using an Emic DL-3000 universal tester (30 kN load cell, 5 mm/min crosshead speed, 100 mm clamp distance, 23 °C, 50 ± 5% RH). Five replicates were tested after 48 h conditioning 3. RESULTS AND DISCUSSION 3.1 XRD studies 3.1.1 Evaluation of basal spacing of bentonites XRD analysis revealed characteristic montmorillonite and kaolinite peaks, indicating smectite-rich clays. Thermal treatment (550 °C) induced structural collapse (Figures 4.1, 4.3), while ethylene glycol treatment expanded interlayers (Figures 4.2, 4.4), confirming smectitic nature. Temperature-induced lattice distortions altered Bragg reflections, affirming smectite clay mineralogy [Bertagnolli ET AL., 2011]. CTAB intercalation increased basal spacing (Figure 4.5), rendering bentonites hydrophobic and enhancing organic adsorption capacity. Figure 4 - XRD patterns: (1 and 3) K-saturated clays (Bofe and Chocolate) - montmorillonite and kaolinite 001 reflections: (a) natural, (b) room temperature, (c) 110°C, (d) 350°C, (e) 550°C. (2 and 4) Mg-saturated clays (Bofe and Chocolate) - montmorillonite and kaolinite 001 reflections: (a) natural, (b) Mg-saturated, (c) ethylene-glycolsolvated. (5) CTAB modified Organo clays: (a) Bofe, (b) Chocolate. 3.1.2 PLA biocomposites XRD patterns (Figure 5) show semi-crystalline characteristics of PLA and PLA/organoclay. Extruded samples exhibit fewer peaks, likely due to crystalline structure disruption during extrusion [Gonzáles-Seligra ET AL., 2017]. It occurs probably due to drying conditions were very different as well. The sheets were quickly dried at high temperatures and high shear stress during extrusion and the films were slowly dried at rest by casting at low temperatures. The casting process helps to promote more effective recrystallization in the matrix, while rapid drying at high temperatures and shear that occurs during
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