Evaluation of mechanical and thermal properties of polimeric nanocomposites based on poly(L-lactide) reinforced by layered hydroxide salts or reinforced by layered double hydroxides

• Grant number: 11/11479-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2012
• End date: November 30, 2014
• Field of knowledge: Engineering - Chemical Engineering
• Principal Investigator: Liliane Maria Ferrareso Lona
• Grantee: Telma Regina Nogueira
• Host Institution: Faculdade de Engenharia Química (FEQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Recently, polymeric nanocomposites reinforced by anionic exchanger having brucite-like arrangement, layered double hydroxides (LDHs) and layered hydroxide salts (LHSs), have attracted considerable scientific interest. In this study "in situ" bulk polymerization of L-lactide in the presence of LDHs or in the presence of LHSs intercalated by organic anions will be investigated, trying to improve some mechanical, barrier and thermal properties of this polymer,in order to try to expand their applications in the packaging industry, especially food. PLLA and PLLA nanocomposites will be produced by ring-opening polymerization of L-lactide using tin (II) 2-ethyl hexanoate as catalyst. The weight fraction (wt%) of reinforcement agents in the polymeric nanocomposites will be fixed in 1% or 2%. PLLA and PLLA nanocomposites will be evaluated through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), flammability test, dynamic mechanical analysis (DMA), flexural strength, UV-visible spectroscopy (UV-Vis), oxygen permeability, gel permeation chromatography and we are also evaluating the possibility of trying to study the effect of the reinforcement agents in the biodegradability of the studied materials. After evaluating the results, LDHs or LHSs that were able to improve PLLA performance, according to the properties studied, will be selected, and these reinforcement agents will be incorporated in the PLLA matrix by intercalation of polymer from solution method. These nanocomposites will be evaluated by the techniques mentioned above, thus, different routes for nanocomposites preparation could be compared.There are few studies in open literature that consider nanocomposites composed by Poly(L-lactide) and layered double hydroxides and as far as the authors know, there is not any study in which a layered hydroxide salt is used as a reinforcement agent for this polymeric matrix. PLLA nanocomposites reinforced by the LDHs that will be synthesized in this work were not found in open literature. (AU)