In this study, melt intercalation method is applied to prepare poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG)-plasticized PLA nanocomposite films including 0, 3, and 5% organoclay (Cloisite 30B) using a laboratory scale compounder, which is connected to a microcast film device. To evaluate the nanomorphology and the dispersion state of the clays, X-ray diffraction (XRD) and transmission electron microscopy (TEM) are conducted. Tensile tests are performed to characterize the mechanical behavior of the films. Biodegradation rate is determined by degradation tests in composting medium. Differential scanning calorimeter (DSC) is applied to observe the thermal behavior of the films. XRD and TEM show that the exfoliation predominantly occurrs in plasticized PLA nanocomposites, whereas unexfoliated agglomerates together with exfoliated clays are observed in the nonplasticized PLA. Tensile tests indicate that the addition of 3% clay to the neat-PLA does not affect the strength; however, it enhances the modulus of the nanocomposites in comparison to neat-PLA. Incorporation of 3% clay to the plasticized PLA improves the modulus with respect to PLA/PEG; on the other hand, the strain at break value is lowered $ 40%. The increase in the rate of biodegradation in composting medium is found as in the order of PLA > PLA/PEG > 3% Clay/PLA/PEG > 5% Clay/PLA/PEG > 3% Clay/PLA. DSC analysis shows that the addition of 3% clay to the neat PLA results in an increase in T g . The addition of 20% PEG as a plasticizer to the neat-PLA decreases T g about 30 C, however incorporation of clays increases T g by 4 C for the plasticized PLA.
The mechanical, thermal, and morphological properties of melt compounded aminopropylisobutylpolyhedral oligomeric silsesquioxane (POSS)/poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG)-plasticized PLA composites were investigated. It was found that the addition of POSS to the PLA reduced the melt viscosity of the composites acting as a lubricating agent. Dynamic mechanical analysis and tensile tests showed that the modulus and elongation at break values improved at low (1% and 3%) POSS loading levels. Scanning electron microscopy observation indicated that POSS particles were well dispersed in both PLA and plasticized PLA. The interfacial interaction of POSS with the polymer matrix was found to be better in the presence of plasticizer. The presence of POSS also affected the thermal properties of the PLA and plasticized PLA. It was revealed from DSC that POSS particles acted as a nucleating agent for PLA. Moreover, the percent crystallinity was found to be higher in the presence of POSS for both PLA and plasticized PLA.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.