Physical properties of plasticized PLA/HNTs bionanocomposites: effects of plasticizer type and content

Abstract

Halloysite nanotubes (HNTs) reinforced polylactic acid (PLA) nanocomposite films were utilized for different applications, such as packaging, drug recover and other applications. The incorporation of plasticizer into polymer nanocomposites modifies some of their functional and physical properties, such as increasing flexibility, moisture sensitivity, in addition to other functional properties. However, the effects of Polyethylen glycol (PEG) and sesame oil (SO) on selected physical properties (moisture content (MC), contact angle (CA) and water vapor permeability (WVP)) of PLA)/HNTs bionanocomposite films were examined. The plasticized PLA/HNTs (5 wt % HNTs loading) bionanocomposite films were prepared using the solution casting method at room temperature. The concentrations of each plasticizer that used indivisually were (0, 10, 20 and 30 wt %). Results show that the increasing of PEG content led to increase in moisture content and water vapor permeability and decrease in contact angle of the films. On the contrary, the increasing of SO levels led to decrease in moisture content and water vapor permeability and increase in contact angle of the films. Differences in measured physical properties of films with plasticizer type and concentration may be attributed to differences in the hydrophilic and hydrophobic properties of the plasticizers. SO was the plasticizer that showed the most interested effect (low moisture content and water vapor permeability) on PLA/HNTs films for food packaging applications compared to PEG.