Biodegradable materials from grafting of modified PLA onto starch nanocrystals

PLA was grafted onto starch nanoparticles using a novel synthetic strategy consisting of three reaction steps. The first step was aimed to protect the hydroxyl groups of PLA by benzoylation (PLABz), the second one involved the activation of carboxyl groups using thionyl chloride and the last reactio...

Full description

Saved in:
Bibliographic Details
Published in:Polymer degradation and stability 2012-10, Vol.97 (10), p.2021-2026
Main Authors: García, N.L., Lamanna, M., D’Accorso, N., Dufresne, A., Aranguren, M., Goyanes, S.
Format: Article
Language:English
Subjects:
Activation
Applied sciences
Benzoylation
Chemically modified starch
Chlorides
Degradation
Exact sciences and technology
Grafting
Hydroxyl groups
Nanocomposites
Nanocrystals
Nanoparticles
Physicochemistry of polymers
Poly (lactic acid)
Polymer industry, paints, wood
Starches
Technology of polymers
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:PLA was grafted onto starch nanoparticles using a novel synthetic strategy consisting of three reaction steps. The first step was aimed to protect the hydroxyl groups of PLA by benzoylation (PLABz), the second one involved the activation of carboxyl groups using thionyl chloride and the last reaction was the grafting of the modified PLA onto the starch nanoparticles (PLASTARCH). The thermal behavior of the composite obtained by this method was very different from that displayed by the physical mixture of PLA and the starch nanoparticles (PLA-NC blend). The benzoylation step that leads to PLABz produces an increase of the molecular mobility, resulting in lower glass transition temperature, Tg, than that of the original PLA; a change that was observed in the DSC thermograms of the samples. On the other hand, the Tg of the PLASTARCH was similar to that of the PLA as a consequence of two opposite effects acting simultaneously: a free volume increase due to the presence of benzoyl groups and a confinement of the polymer chain, originating from the grafting onto NC. The material obtained by chemical modification (PLASTARCH) has a degradation temperature slightly lower than that of PLA, which does not affect its potential use in the packaging industry.
ISSN:0141-3910
1873-2321
DOI:10.1016/j.polymdegradstab.2012.03.032