Fabrication and characterization of novel starch-grafted poly L-lactic acid/montmorillonite organoclay nanocomposites

Egri O., Salimi K., EĞRİ S., Piskin E., Rzayev Z. M. O.

CARBOHYDRATE POLYMERS, vol.137, pp.111-118, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 137
  • Publication Date: 2016
  • Doi Number: 10.1016/j.carbpol.2015.10.043
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.111-118
  • Hacettepe University Affiliated: Yes


In this work, poly(L-lactic acid)-g-starch layered silicate nanocomposites (NCs) (PLLA-g-starch/MMT) were fabricated by intercalative bulk graft copolymerization of LA with starch, in the presence of either stannous octoate acting as a catalyst or LA-MMT organoclay acting as a cocatalyst-nanofiller. This procedure was performed inside a custom vacuum micro-reactor. To better understand the graft copolymerization mechanism, in situ processing types, interfacial interactions and nanostructure formation of PLLA-g-starch/MMT NCs, methods such as FT-IR, XRD, H-1 NMR, C-13 CP/MAS-NMR, DSC/TGA, TEM and SEM were utilized. The morphology and thermal behaviors of nanocomposites were found to be strongly dependent on the loading mass fraction of LA-MMT within the nanocomposite structure and the type of in situ processing such as interfacial, physical and chemical interactions. Preintercalated LA-MMT organoclay exhibited dual functions. It demonstrated the ability to act as a catalyst, essentially accelerating in situ graft copolymerization via esterification of LA carboxyl groups with hydroxyl groups of starch macromolecules, whilst also acting as a nananofiller-compatibilizer. (C) 2015 Elsevier Ltd. All rights reserved.