organoclay was added to the PLA solution. 18 mL of each solution was poured into Petri dishes (φ 150 mm) and dried for 48 h at room conditions. 2.2.2 Extrusion Masterbatch preparation: 15 g organoclay was dispersed in 300 mL chloroform (ice bath, tipultrasound: 2 × 3 min, 50% amplitude). 15 g PLA was dissolved in 500 mL chloroform (magnetic stirring). Dispersed clay was mixed with PLA solution (tip-ultrasound: 5 min, ice bath). Solution was poured into Petri dishes, dried, cut, and oven-dried (50 °C). Nanocomposite (4 wt% organoclay): 228 g PLA + 24 g masterbatch extruded in twin-screw extruder (L/D = 25, D = 19 mm, BA Process Equipment MP19). Temperature: 170, 175, 180, 175, 180 °C. Rotation: 100 rpm. Filament pelletized, dried (60 °C, 24 h), and injection-molded (Arburg Allrounder 270S 400-100) into ASTM D638 Type I specimens. Conditions: 170-210 °C, 2500 bar, mold: 30 °C, cooling: 50 s. See Figure 3 for overview. Figure 3 – Overview of biocomposite production process using bentonite fines from mineral beneficiation for ecofriendly food packaging 2.3 Characterizations The raw materials and biomaterials, processed via casting and extrusion, were characterized for their chemical, structural, thermal, morphological, and mechanical properties. XRD patterns were obtained using a Bruker D4 Endeavor diffractometer with Co Kα radiation (40 kV/40 mA). Scans were performed over a 2θ range of 5-80°, with a 0.02° step and a LynxEye detector. To evaluate basal spacing modifications, clay samples were subjected to ethylene glycol solvation (12 h) and calcination (550°C, 1 h). FTIR spectra were recorded using a PerkinElmer Spectrum 100 spectrometer equipped with an attenuated total reflection (ATR) accessory. Spectra were acquired over a wavenumber range of 4000-600 cm⁻¹, with 32 scans per sample and a spectral resolution of 4 cm⁻¹. TGA was performed on a Mettler Toledo TGA/DSC 1 STARe System, operating from 25 to 1000 °C at a heating rate of 10 °C/min, using a platinum sample holder under a nitrogen atmosphere. DSC analyses were performed on a TA Instruments Q200 calorimeter. Samples (∼10 mg) were heated from 40 to 200 °C (10 °C/min). Thermal transitions, including glass transition (Tg), crystallization (Tc), and melting (Tm) temperatures, were determined from the second heating cycle. Crystallinity (Xc) was calculated as: Xc = 100 (ΔHc –ΔHm /ΔHm100%) (%)
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