Enhanced thermal stability of “environmentally friendly” biodegradable poly(Lactic acid) blends with cellulose acetate. an experimental and molecular modeling study

Funding Number

FY15/51

Funding Sponsor

American University in Cairo

Author's Department

Chemistry Department

Document Type

Research Article

Publication Title

Biointerface Research in Applied Chemistry

Publication Date

1-1-2017

Abstract

© 2017 by the authors. Cellulose acetate (CA) is added to the “Environmentally friendly” poly(lactic acid) (PLA) to improve its materials stiffness and thermal stability for use in various applications. Stress-strain showed that small amounts of CA had contributed to PLA flexibility while maintaining high values for the stress. The improved mechanical properties of the samples signifies the stability of the blend due to the formation of 3D-hydrogen bonding network between the CA and PLA chains as indicated by FTIR analysis. Extended thermal degradation highlighted the susceptibility of neat PLA chains to degradation over extended periods of time. The presence of CA component protected PLA chains as a result of the crosslinking between the resultant free radicals and the polymeric chains, which increased the molecular weight of the samples and its overall toughness. Molecular simulations showed that enthalpy of mixing had positive values at low temperatures indicating blend instability as the entropic contribution to free energy of mixing was not sufficient to overcome the enthalpic-driven phase separation. Greater free energy values at higher PLA content coincided with the experimental observation that blends with high PLA content showed appreciable mechanical response whereas those with higher CA content showed no mechanical integrity as predicted by molecular modeling.

First Page

2230

Last Page

2237

This document is currently not available here.

Share

COinS