Activation energy for crystallization of low molecular weight poly(ethylene oxide) and low molecular weight poly(ethylene oxide)/poly(methyl methacrylate) blends determined by DSC and polarized optical microscopy

• Published in: Thermochimica acta 1995-12, Vol.267, p.259-268
• Main Authors: Imai, Shinya, Shimono, Shinji, Fukushima, Yousuke, Umezaki, Kazuyuki, Okada, Motoyuki, Takahashi, Masato, Matsuda, Hideomi
• Format: Article
• Language: English
• Subjects: Applied sciences; Crystallization; DSC; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polarized optical microscopy; Poly(ethylene oxide); Poly(ethylene oxide)/poly(methyl methacrylate) blends; Properties and characterization
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/0040-6031(95)02484-0

The crystallization process of poly(ethylene oxide) (PEO) and PEO/poly(methyl methacrylate) (PMMA) blends in the low molecular weight region of PEO was studied by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The half-time of the crystallization t 1 2 , the time at which crystallinity X(t) = 1 2 , was inversely proportional to the linear growth rate G of spherulite, i.e. t 1 2 −1 ∝ G . The value of E characterizes the temperature dependence of the activation energy for the formation of a secondary nucleus on the growing side surface of the crystal lamella and was evaluated from the t 1 2 measured by DSC. The value of E of PEO was not affected by blending PMMA. However, the slightly increasing tendency of E was observed for PEO and PEO/PMMA blends with increasing molecular weight of PEO, M PEO. This tendency may correspond to the crossover of E from low molecular weight material to polymer.