| 초록 |
Poly(L-lactide) and poly(D-lactide) were synthesized by ring-opening polymerization with stannous octoate [Sn(Oct)2] and 1-dodecanol as initiator and coinitiator, respectively. The reactions were carried out at different temperatures and reaction times in solid-state polymerization. Chemical structures of the products were confirmed by FT-IR and 1H-NMR, and the molecular weights were estimated by gel permeation chromatography (GPC). Stereocomplex PLA was obtained by mixing an equal amount of each enantiomeric polymer in the molten state. Moreover, the effect of the PLLA and PDLA molecular weight to stereocomplex formation were studied. The resulting polymers were characterized by X-ray diffraction (XRD) measurements by comparing with each enantiomeric poly(lactide). Also, the Tg, Tm and thermal degradation properties of the products were analyzed to find out the improvement of thermal properties by using the differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). |
