Small amounts of poly(d-lactic acid) on the properties of poly(l-lactic acid)/microcrystalline cellulose/ poly(d-lactic acid) blends

Abstract

Stereocomplexation is utilized to improve and control the mechanical and thermal properties of poly(lactic acid) (PLA) where enantiomeric polymers poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) form stereocomplexation. This research reports the effects of minor amounts of PDLA on the properties of PLLA/microcryslalline cellulose (MCC)/PDLA blends. Blends of PLLA/MCC/PDLA are prepared with constant percentage of MCC and different percentage of PLLA and PDLA by solution casting methods and are characterized by FTIR for the confirmation of blends compatibility, WAXS and SEM for the analysis of morphology, TGA and DTA for thermal properties measurement. Shifting of peaks of FTIR profiles observe in blends with and without PDLA due to hydrogen bonding which helps to have compatibility of blends component. XRD analysis show three new peaks after adding PDLA in PLLA/MCC blends confirm the formation of stereocomplex (SC) crystalline structure. TGA and DTG results indicate that PDLA can improve the heat resistivity of the PLLA/MCC blends by increasing its degradation temperature. DTA peaks profile also ensure the development of thermal properties. Image of SEM show the improvement of surface morphology.