ao7b00387_si_001.pdf (8.74 MB)
Preparation of Cellulose Nanocrystal-Reinforced Poly(lactic acid) Nanocomposites through Noncovalent Modification with PLLA-Based Surfactants
journal contribution
posted on 2017-06-16, 11:34 authored by Marcos Mariano, Florence Pilate, Franciéli
Borges de Oliveira, Farid Khelifa, Philippe Dubois, Jean-Marie Raquez, Alain DufresneCellulose
nanocrystal (CNC)-reinforced poly(lactic acid) (PLA)
nanocomposites were prepared by twin-screw extrusion followed by injection-molding
using a masterbatch approach. Noncovalent modification of CNCs was
performed with two different poly(l-lactide) (PLLA)-based surfactants to improve the
filler/matrix compatibility. They both have a PLLA block that is expected
to improve the compatibility with the PLA matrix and differ by the
polar head. It consists of either a poly(ethylene glycol) (PEG) block
(PEG-b-PLLA) or an imidazolium group (Im-PLLA), that
is able to interact with the surface of
the CNCs. The morphological, structural, thermal, rheological, and
mechanical properties of the nanocomposites were investigated. The
different modes of interaction of the polar head of the surfactant
lead to different properties. However, the global decrease in the
molecular weight of PLA, induced by the short PLLA blocks from the
surfactants and the possible degradation during melt processing, results
in a plasticization effect and impacts the crystallization of the
matrix.