Poly(lactic acid)/acetylated starch blends: Effect of starch acetylation on the material properties

Rasool Nasseri; Robert Ngunjiri; Christine Moresoli; Aiping Yu; Zhongshun Yuan; Chunbao Charles Xu

doi:10.1016/j.carbpol.2019.115453

Poly(lactic acid)/acetylated starch blends: Effect of starch acetylation on the material properties

Carbohydr Polym. 2020 Feb 1:229:115453. doi: 10.1016/j.carbpol.2019.115453. Epub 2019 Oct 11.

Authors

Rasool Nasseri¹, Robert Ngunjiri¹, Christine Moresoli², Aiping Yu³, Zhongshun Yuan⁴, Chunbao Charles Xu⁴

Affiliations

¹ Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
² Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. Electronic address: cmoresol@uwaterloo.ca.
³ Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada; Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
⁴ Institute for Chemicals and Fuels from Alternative Resources, Department of Chemical & Biochemical Engineering, Western University, London, Ontario, N6A 5B9, Canada.

PMID: 31826416
DOI: 10.1016/j.carbpol.2019.115453

Abstract

This study investigated the acetylation of starch to improve its processability and compatibility with poly(lactic acid). The temperature at the maximum rate of degradation increased by 3.2% for poly(lactic acid) blends containing acetylated starch degree of substitution 2.5 compared to the blend containing neat starch. A biphasic morphology with distinct dispersed phase was predicted and observed experimentally for all blends except the blend containing acetylated starch degree of substitution 3. Acetylated starch induced plasticization and nucleation for all degree of substitution. The blend containing acetylated starch degree of substitution 2.5 had higher tensile strength (26%), and toughness (29%) compared to the blend containing neat starch. The superior mechanical properties of the blend containing acetylated starch degree of substitution 2.5 are attractive for medical implant applications. The continuous microstructure and transparency characteristics of the blend containing acetylated starch degree of substitution 3 are attractive for packaging applications.

Keywords: Acetylated starch; Mechanical properties; Phase behavior; Poly(lactic acid); Thermal stability; Thermal transition; Transport properties.