Modification of Brittle Polylactide by Novel Hyperbranched Polymer-Based Nanostructures
Open Access
- 3 July 2007
- journal article
- research article
- Published by American Chemical Society (ACS) in Biomacromolecules
- Vol. 8 (8), 2476-2484
- https://doi.org/10.1021/bm070367x
Abstract
The inherent brittleness of polylactide (PLA) poses considerable scientific challenges and limits its large-scale applications. Here, we propose and demonstrate a new industrially relevant methodology to develop a polylactide (PLA)-based nanoblend having outstanding stiffness-toughness balance. In this approach, a hydroxyl functional hyperbranched polymer (HBP) was in-situ cross-linked with a polyanhydride (PA) in the PLA matrix during melt processing. There was formation of new hyperbranched polymer-based cross-linked particles in the PLA matrix. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) revealed the sea-island morphology of PLA-cross-linked HBP blend. The domain size of cross-linked HBP particles in the PLA matrix was less than 100 nm as obtained from TEM. The presence of cross-linked hyperbranched polymer in the PLA matrix exhibited approximately 570% and approximately 847% improvement in the toughness and elongation at break, respectively, as compared to unmodified PLA. The increase in the ductility of modified PLA was related to stress whitening and multiple crazing initiated in the presence of cross-linked HBP particles. Formation of a networked interface as revealed by rheological data was associated with enhanced compatibility of the PLA-cross-linked HBP blend as compared to the PLA/HBP blend. The cross-linking reaction of HBP with PA was confirmed with the help of Fourier transform infrared spectroscopy (FTIR) and low-temperature dynamical mechanical thermal analysis (DMTA).Keywords
This publication has 27 references indexed in Scilit:
- Formation of Nanostructured PVDF/PA11 Blends Using High-Shear ProcessingMacromolecules, 2005
- Preparation and Properties of Plasticized Poly(lactic acid) FilmsBiomacromolecules, 2005
- Block copolymers in tomorrow's plasticsNature Materials, 2005
- Free Energy of Mixing of Cross-Linked Polymer BlendsLangmuir, 2004
- Constrained nonlinear optimization for solubility parameters of poly(lactic acid) and poly(glycolic acid)—validation and comparisonPolymer, 2004
- Homogeneous reactive coupling of terminally functional polymersPolymer, 2001
- A review of dendritic hyperbranched polymer as modifiers in epoxy compositesComposites Science and Technology, 2001
- Reactive Extrusion: Toward NanoblendsMacromolecules, 1999
- (Co)polymers of L‐lactide, 2. Mechanical propertiesMacromolecular Chemistry and Physics, 1994
- A new mechanism of toughening glassy polymers. 2. Theoretical approachMacromolecules, 1990