Next Article in Journal
Methylcellulose, a Cellulose Derivative with Original Physical Properties and Extended Applications
Previous Article in Journal
Characterization of Novel Castor Oil-Based Polyurethane Polymer Electrolytes
Article Menu

Export Article

Open AccessArticle
Polymers 2015, 7(4), 760-776; doi:10.3390/polym7040760

Effect of Artificial Weathering on PLA/Nanocomposite Molecular Weight Distribution

1
Centro de Investigación en Materiales Avanzados, S.C., Miguel de Cervantes No. 120, C.P. 31136, Complejo Industrial Chihuahua, Chihuahua, Mexico
2
Universidad Autónoma de Zacatecas; Unidad Académica de Ciencias de la Tierra, Calzada de la Universidad 108, Zacatecas, Mexico
3
Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Circuito Universitario s/n, Campus Universitario No. 2, C.P. 31125, Chihuahua, Mexico
These authors contributed equally to this work.
*
Author to whom correspondence should be addressed.
Academic Editor: João F. Mano
Received: 23 January 2015 / Revised: 3 April 2015 / Accepted: 16 April 2015 / Published: 22 April 2015
View Full-Text   |   Download PDF [8904 KB, uploaded 22 April 2015]   |  

Abstract

The reduction of polylactide acid (PLA) molecular weight for amorphous and semicrystalline grade nanocomposites with 5 wt% load of organomodified montmorillonite Cloisite30B (C30B) was investigated in periods of up to 360 h under artificial weathering. A correlation between artificial and natural weathering was established. The nanocomposites were prepared by mixing the C30B in PLA matrix using two stages of extrusion followed by injection molding. In addition, we also studied materials without C30B in PLA matrix prepared by a single stage of injection, as well as with two stages of extrusion followed by injection, in order to assess thermal effects. XRD (X-ray diffraction) and TEM (Transmission electron microscope) were used to determine the layer dispersion of the C30B within the PLA. An increase in the interlayer spacing of a sandwich structure corresponding to a partial exfoliation of the C30B was found, leading to the creation of small particles at nanoscale of one (1.29 nm) to eight (11.76 nm) platelets. Also, GPC (Gel permeation chromatography) was used to evaluate the molecular weight decay of neat PLA and its nanocomposites due to thermal processing and subsequent artificial weathering exposure. From thermal processing, a more significant decrease of polydispersity in amorphous PLA than in semicrystalline PLA counterparts could be observed. First order fitting of molecular weight decay of samples versus time of exposure under artificial weathering was found for all materials tested. It was observed that the addition of clay favored PLA degradation in amorphous PLA, in comparison with semicrystalline PLA in both thermal processing and artificial weathering. Moreover, a possible effect of C30B interactions with PLA chains under artificial weathering could be postulated. View Full-Text
Keywords: artificial weathering; natural weathering; PLA/nanocomposite; molecular weight; cloisite30B artificial weathering; natural weathering; PLA/nanocomposite; molecular weight; cloisite30B
Figures

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Chávez-Montes, W.M.; González-Sánchez, G.; López-Martínez, E.I.; de Lira-Gómez, P.; Ballinas-Casarrubias, L.; Flores-Gallardo, S. Effect of Artificial Weathering on PLA/Nanocomposite Molecular Weight Distribution. Polymers 2015, 7, 760-776.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Polymers EISSN 2073-4360 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top