Properties of linear poly(lactic acid)/polyethylene glycol blends

Abstract

Poly(lactic acid) (PLA) has great potentials to be processed into films for packaging applications. However, film production is difficult to carry out due to the brittleness and low melt strength of PLA. In this investigation, linear PLA (L‐PLA) was plasticized with poly(ethylene glycol) (PEG) having MW of 1000 g mol−1 in various PEG concentrations (0, 5, 10, 15, and 20 wt%). In relation to plasticizer content, the impact resistance and crystallinity of L‐PLA was increased, whereas a decrease in glass transition temperature and lower stiffness was observed. Nevertheless, the phase separation has been found in samples which contained PEG greater than 10 wt%. The dynamic and shear rheological studies showed that the plasticized PLA possessed lower viscosity and more pronounced elastic properties than that of pure PLA. Both storage and loss moduli decreased with PEG loading at all frequencies while storage modulus exhibited weak frequency dependence with increasing PEG content. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers

Effect of plasticizers on thermal and physical properties of compression-moulded poly[(3-hydroxybutyrate)-co-(3-hydroxyvalerate)] films

“…Non-plasticized PHBV films showed quite a homogeneous structure, exhibiting typical brittle fracture in most of the observed areas, as previously reported by other authors [36]. Nevertheless, plastic deformation and a few threads of a deformed material are discernible on the fracture surface of plasticized films between the brittle zones, as has been described for semicrystalline polymers [37], which was promoted by the plasticizing effect of the amorphous regions in the films. Whereas no notable microstructural effect was observed when PEGs were incorporated to the films, the addition of fatty acids (LA and SA) enhanced the roughness of the surface fracture, thus indicating a different rearrangement of the polymer molecules due to the specific interactions with these less polar plasticizers.…”

Enhanced dispersion of cellulose nanocrystals in melt-processed polylactide-based nanocomposites

“…PLA and PEO grades were similar to those proposed in the present study. They reported that full crystallization upon cooling at 10°C/min is attained when PEO concentration is higher than 15 wt%; this is mostly explained by the increase in polymer chain mobility due to the plasticization effect of PEO (Sungsanit et al 2012). This fact supports the idea that PEO and CNC have a synergistic effect on the crystallization process of PLA/CNC nanocomposites.…”

“…We observe that the low molecular weight PEO decreases the transition temperature and increases the rate of crystallization of the PLA matrix. Previous studies have reported a decrease of about 15°C in PLA/PEG blends containing 10 wt% of PEG of molecular weights from 1,000 to 20,000 g/mol (Sheth et al 1997;Sungsanit et al 2012). In all cases, the storage modulus values after recovery were similar (about 0.1 GPa) and the net loss (difference between final and initial value) in the storage modulus was about 1 decade.…”

Poly(lactic acid)/Poly(ethylene glycol) Polymer Nanocomposites: Effects of Graphene Nanoplatelets

“…It has been found that PEG shows great promise as a plasticizing agent for PLA as it gives a large increase in elongation at break [11][12][13][14][15][16]. However, this is accompanied by a dramatic loss in tensile strength and tensile modulus.…”