MSc Thesis Defense: Armita Safari, LACTIDE GRAFTING ONTO ALKALI-ACTIVATED CELLULOSE VIA RING-OPENING POLYMERIZATION: EFFECTS OF REACTION CONDITIONS ON MATERIAL PROPERTIES, Date & Time: 21 July, 2026 – 2:00 PM, Place: FENS L027

LACTIDE GRAFTING ONTO ALKALI-ACTIVATED CELLULOSE VIA RING-OPENING POLYMERIZATION: EFFECTS OF REACTION CONDITIONS ON MATERIAL PROPERTIES

Armita Safari
Materials Science and Nano Engineering, MSc Thesis, 2026

Thesis Jury

     Prof. Yusuf Ziya Menceloğlu (Thesis Advisor)

  Prof. Serkan Ünal

  Prof. Cem Bülent Üstündağ

Date & Time: 21st of July, 2026 – 2:00 PM

Place: FENS L027

Keywords : alkali-activated cellulose, polycotton textile waste, L-lactide, ring-opening polymerization, solvent extraction

Abstract

Cellulose obtained from polycotton textile waste offers a renewable raw material for biodegradable polymer systems; however, its low compatibility with polyester matrices limits its direct use. In this study, alkali-activated cellulose was modified through the Sn(Oct)2-catalyzed ring-opening polymerization of L-lactide. The effects of the lactide-to-cellulose ratio, catalyst loading, reaction time, temperature, reaction atmosphere, plasticizer addition, cellulose source, and alkali activation conditions were evaluated. The resulting products were characterized using Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), solvent extraction, Soxhlet ex- traction, optical microscopy, and intrinsic viscosity measurements. FTIR analysis revealed ester-related bands after polymerization. However, because the cellulose-free PLA control also exhibited similar signals, FTIR analysis alone was insufficient to confirm the formation of cellulose-g-PLA. Therefore, chloroform extraction and dichloromethane (DCM) Soxhlet extraction were used to separate removable PLA-like material from the cellulose-associated fractions. While the cellulose-free control sample was completely removed by Soxhlet extraction, insoluble fractions exhibiting ester-related functionality were retained in the selected cellulose-containing samples. This distinction was further supported by XRD, thermal analysis, and morphological observations. Among the investigated conditions, the formulation prepared using 20 μL Sn(Oct)2 at 120 ◦C for 4 h with a lactide-to-cellulose ratio of 10:1 (w/w) exhibited the most consistent overall performance, providing a favorable combination of product recovery, ester-related FTIR response, and thermal stability. Overall, the results support the formation of cellulose-associated lactide-derived material.