Plasticized and unplasticized PLA/organoclay nanocomposites: Short- and long-term thermal properties, morphology, and nonisothermal crystallization behavior

GÜMÜŞ S., ÖZKOÇ G., AYTAÇ A.

JOURNAL OF APPLIED POLYMER SCIENCE, cilt.123, sa.5, ss.2837-2848, 2012 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 123 Sayı: 5
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1002/app.34841
  • Dergi Adı: JOURNAL OF APPLIED POLYMER SCIENCE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.2837-2848
  • Anahtar Kelimeler: PLA, nanocomposite, plasticization, physical aging, nonisothermal crystallization, POLY(LACTIDE)/POLY(ETHYLENE GLYCOL) BLENDS, GLASS-FORMING MELTS, COLD-CRYSTALLIZATION, CATALYZED NUCLEATION, PHASE-CHANGE, KINETICS, POLY(L-LACTIDE), POLY(LACTIDE), POLYLACTIDE, MISCIBILITY
  • Kocaeli Üniversitesi Adresli: Evet

Özet

The short- and long-term thermal properties, organoclay dispersion state, and the nonisothermal crystallization kinetics of organoclay based nanocomposites of poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) plasticized PLA were investigated. Differential scanning calorimetry analyses showed that plasticization of PLA/PEG blend was diminished due to physical aging by the time. The change in thermal properties such as glass transition temperature, cold crystallization temperature, and melting temperature was monitored. It was revealed from X-ray diffraction analyses that in long term, the exfoliated and/or intercalated organoclay structure of nanocomposites observed in short term (just after processing) was differentiated to a tactoidal form (i.e., nonseparated clays). The nonisothermal crystallization behavior and kinetics were examined by using Avrami, Ozawa, and combined Avrami-Ozawa models. Moreover, the nucleating effect of clays was investigated in terms of Gutzow and Dobrewa approaches. It was found out that clays did not act as nucleating agents in plasticized PLA nanocomposites, which was also in good agreement with activation energy values obtained from Kissinger and Takhor models. (c) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123:2837-2848, 2012