Table of Contents
Journal of Polymers
Volume 2013 (2013), Article ID 162603, 10 pages
http://dx.doi.org/10.1155/2013/162603
Research Article

Structure/Property Relationships of Poly(L-lactic Acid)/Mesoporous Silica Nanocomposites

1Facultad de Ciencias Químicas, CIEP-FCQ, Universidad Autónoma de San Luis Potosí, Avenida Dr. Manuel Nava Martínez 6, 78210 San Luis Potosí, SLP, Mexico
2Centro de Investigación en Química Aplicada, Boulevard Enrique Reyna 140, P.O. Box 379, 25100 Saltillo, COAH, Mexico

Received 29 June 2013; Revised 7 October 2013; Accepted 8 October 2013

Academic Editor: Zhong-Ming Li

Copyright © 2013 Javier Gudiño-Rivera et al. 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.

Abstract

Biodegradable poly(L-lactic acid) (PLLA)/mesoporous silica nanocomposites were prepared by grafting L-lactic acid oligomer onto silanol groups at the surface of mesoporous silica (SBA-15). The infrared results showed that the lactic acid oligomer was grafted onto the mesoporous silica. Surface characterization of mesoporous silica proved that the grafted oligomer blocked the entry of nitrogen into the mesopores. Thermal analysis measurements showed evidence that, once mixed with PLLA, SBA-15 not only nucleated the PLLA but also increased the total amount of crystallinity. Neat PLLA and its nanocomposites crystallized in the same crystal habit and, as expected, PLLA had a defined periodicity compared with the nanocomposites. This was because the grafted macromolecules on silica tended to cover the lamellar crystalline order. The g-SBA-15 nanoparticles improved the tensile moduli, increasing also the tensile strength of the resultant nanocomposites. Overall, the silica concentration tended to form a brittle material.