ScCO2-processed thermoplastic starch/chitosan oligosaccharide blown films and their oxygen barrier or antibacterial applications.

Autor: Wang, Zi-yu, Luo, Qian-li, Mei, Han-fang, Ma, Ning, Huang, Ya-qiong, Yeh, Jen-taut
Předmět:
Zdroj: Journal of Polymer Engineering; Oct2024, Vol. 44 Issue 9, p679-694, 16p
Abstrakt: Antibacterial and oxygen barrier films were inventively prepared by blending very small loadings (<2 wt%) of chitosan oligosaccharide (COS) or chitosan (CS) in thermoplastic starch (TPS) and/or processing with supercritical carbon dioxide (scCO2). Oxygen transmission rates (OTR) and free-volume-hole (FVH) characteristics of scCO2-processed TPS/COS and TPS/CS blown films diminish to a minimum, as their COS or CS approach a specific compatibility limit content. The minimum OTR and FVH characteristics of scCO2-processed TPS/COS films are somewhat smaller than those of corresponding TPS/COS films without scCO2-assistance, and decrease further with decreasing COS molecular weights. The minimum OTR values of scCO2-processed TPS/COS blown films with COS's molecular weight of 200 and 500 are only 4.1 and 4.5 cm3/m2 × day × atm, respectively, and their antibacterial rates of Staphylococcus aureus are ≥97 %, which make them as promising antibacterial and oxygen barrier films having OTR ≦ 5 cm3/m2 × day × atm. Among other things, longitudinal or transversal tensile strengths acquired for the properly scCO2-processed TPS/COS or TPS/CS films are ∼30 to ∼50 % higher than those of the TPS films. Dynamic mechanical relaxation results of these scCO2-processed reveal that chitosan oligosaccharide or chitosan are compatible with TPS, as COS or CS contents are ≤ the compatibility limit value. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index