TY - JOUR
T1 - Effect of lower critical solution temperature phase separation on crystallization kinetics and morphology of poly(butylenes succinate)/ poly(ethylene oxide) blend
AU - He, Zhiyuan
AU - Liang, Yongri
AU - Wang, Pingli
AU - Han, Charles C.
PY - 2013/4/19
Y1 - 2013/4/19
N2 - The crystalline/crystalline polymer blend of poly(butylenes succinate)/poly(ethylene oxide) (PBS/PEO) exhibited lower critical solution temperature (LCST) phase separation behavior at temperatures above the melting point of PBS, which was measured by phase contrast optical microscopy (PCOM) technique. In this work, we determined the LCST phase diagram of PBS/PEO blends, and then investigated the effect of liquid-liquid phase separation (LLPS) on the crystallization kinetics and morphologies of PBS/PEO (40/60 wt/wt) blend. Based on polarized optical microscopy (POM), scanning electron microscopy (SEM) and differential scanning calorimeter (DSC) results, we found that the spherulite morphology and crystallization kinetics of PBS were strongly influenced by the initial LLPS structure; because the kinetics of liquid-liquid phase dissolution was much slower than that of crystallization. The effect of LLPS on the primary nucleation density and crystal growth rate of PBS were strongly dependent on the crystallization temperature of PBS. After a second quench to a temperature below the melting point of PEO, the fractionated crystallization of PEO was observed. The competition between the kinetics of LLPS and the driving force of PBS crystallization controlled the spatial distribution of PEO in PBS spherulites, thus essentially determined the confined conditions of the PEO crystallization. The results indicated that the LLPS was an effective process to control the crystallization kinetics and morphology in crystalline/crystalline polymer blend systems.
AB - The crystalline/crystalline polymer blend of poly(butylenes succinate)/poly(ethylene oxide) (PBS/PEO) exhibited lower critical solution temperature (LCST) phase separation behavior at temperatures above the melting point of PBS, which was measured by phase contrast optical microscopy (PCOM) technique. In this work, we determined the LCST phase diagram of PBS/PEO blends, and then investigated the effect of liquid-liquid phase separation (LLPS) on the crystallization kinetics and morphologies of PBS/PEO (40/60 wt/wt) blend. Based on polarized optical microscopy (POM), scanning electron microscopy (SEM) and differential scanning calorimeter (DSC) results, we found that the spherulite morphology and crystallization kinetics of PBS were strongly influenced by the initial LLPS structure; because the kinetics of liquid-liquid phase dissolution was much slower than that of crystallization. The effect of LLPS on the primary nucleation density and crystal growth rate of PBS were strongly dependent on the crystallization temperature of PBS. After a second quench to a temperature below the melting point of PEO, the fractionated crystallization of PEO was observed. The competition between the kinetics of LLPS and the driving force of PBS crystallization controlled the spatial distribution of PEO in PBS spherulites, thus essentially determined the confined conditions of the PEO crystallization. The results indicated that the LLPS was an effective process to control the crystallization kinetics and morphology in crystalline/crystalline polymer blend systems.
KW - Crystallization
KW - Lower critical solution temperature phase separation
KW - Poly(butylenes succinate)/poly(ethylene oxide) blends
UR - http://www.scopus.com/inward/record.url?scp=84876027324&partnerID=8YFLogxK
U2 - 10.1016/j.polymer.2013.02.020
DO - 10.1016/j.polymer.2013.02.020
M3 - Article
AN - SCOPUS:84876027324
SN - 0032-3861
VL - 54
SP - 2355
EP - 2363
JO - Polymer
JF - Polymer
IS - 9
ER -