TY - JOUR
T1 - Polyethylene Blends for Improved Oxygen Barrier
T2 - Processing-Dependent Microstructure and Gas Permeability
AU - Kim, Kyungtae
AU - Zervoudakis, Aristotle J.
AU - LaNasa, Jacob A.
AU - Haugstad, Greg
AU - Zhou, Fang
AU - Lee, Bongjoon
AU - Lhost, Olivier
AU - Trolez, Yves
AU - Bates, Frank S.
AU - Macosko, Christopher W.
N1 - Publisher Copyright:
© 2023 American Chemical Society.
PY - 2024/1/12
Y1 - 2024/1/12
N2 - This work demonstrates a greater than expected enhancement of oxygen barrier properties in linear low-density polyethylene (LLDPE)-based materials by blending LLDPE with high-density polyethylene (HDPE). The films made by melt pressing the LLDPE/HDPE blends had a greater reduction in oxygen permeability coefficients (PO2) than predicted using common permeability reduction models, i.e., the harmonic average model and zero-permeability nanofiller model. The reduction of PO2 was attributed to the presence of spherulite crystal structures, as revealed by atomic force microscopy combined with infrared spectroscopy (AFM-IR). The LLDPE matrix exhibited significant spherulite formation even at a relatively low addition of HDPEs, which likely formed tortuous pathways for diffusing oxygen molecules. Transport results from melt-pressed films contrast with the results from films with similar compositions prepared by film blowing, which did not show barrier enhancement beyond expectation. AFM-IR revealed that the blown films lacked spherulite crystals likely due to stretching in the machine direction followed by rapid cooling. These findings demonstrate the role of processing in controlling microstructures and thus the oxygen barrier performance. This work offers the possibility of achieving easily recyclable LLDPE-based packaging materials by simple blending of polyethylenes with different crystalline content.
AB - This work demonstrates a greater than expected enhancement of oxygen barrier properties in linear low-density polyethylene (LLDPE)-based materials by blending LLDPE with high-density polyethylene (HDPE). The films made by melt pressing the LLDPE/HDPE blends had a greater reduction in oxygen permeability coefficients (PO2) than predicted using common permeability reduction models, i.e., the harmonic average model and zero-permeability nanofiller model. The reduction of PO2 was attributed to the presence of spherulite crystal structures, as revealed by atomic force microscopy combined with infrared spectroscopy (AFM-IR). The LLDPE matrix exhibited significant spherulite formation even at a relatively low addition of HDPEs, which likely formed tortuous pathways for diffusing oxygen molecules. Transport results from melt-pressed films contrast with the results from films with similar compositions prepared by film blowing, which did not show barrier enhancement beyond expectation. AFM-IR revealed that the blown films lacked spherulite crystals likely due to stretching in the machine direction followed by rapid cooling. These findings demonstrate the role of processing in controlling microstructures and thus the oxygen barrier performance. This work offers the possibility of achieving easily recyclable LLDPE-based packaging materials by simple blending of polyethylenes with different crystalline content.
KW - blown films
KW - oxygen barrier
KW - polyethylene packaging
KW - polymer blends
KW - polymer crystallization
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U2 - 10.1021/acsapm.3c02211
DO - 10.1021/acsapm.3c02211
M3 - Article
AN - SCOPUS:85180093638
SN - 2637-6105
VL - 6
SP - 524
EP - 533
JO - ACS Applied Polymer Materials
JF - ACS Applied Polymer Materials
IS - 1
ER -