Disentanglement induced by uniaxial pre-stretching as a key factor for toughening poly( -lactic acid) sheets

Polymer ◽  
2018 ◽  
Vol 140 ◽  
pp. 47-55 ◽  
Author(s):  
Yunjing Chen ◽  
Lijing Han ◽  
Dandan Ju ◽  
Tingting Liu ◽  
Lisong Dong
2018 ◽  
Vol 9 ◽  
pp. 1328-1338 ◽  
Author(s):  
María Francisca Matus ◽  
Martín Ludueña ◽  
Cristian Vilos ◽  
Iván Palomo ◽  
Marcelo M Mariscal

Nanotherapeutics is a promising field for numerous diseases and represents the forefront of modern medicine. In the present work, full atomistic computer simulations were applied to study poly(lactic acid) (PLA) nanoparticles conjugated with polyethylene glycol (PEG). The formation of this complex system was simulated using the reactive polarizable force field (ReaxFF). A full picture of the morphology, charge and functional group distribution is given. We found that all terminal groups (carboxylic acid, methoxy and amino) are randomly distributed at the surface of the nanoparticles. The surface design of NPs requires that the charged groups must surround the surface region for an optimal functionalization/charge distribution, which is a key factor in determining physicochemical interactions with different biological molecules inside the organism. Another important point that was investigated was the encapsulation of drugs in these nanocarriers and the prediction of the polymer–drug interactions, which provided a better insight into structural features that could affect the effectiveness of drug loading. We employed blind docking to predict NP–drug affinity testing on an antiaggregant compound, cilostazol. The results suggest that the combination of molecular dynamics ReaxFF simulations and blind docking techniques can be used as an explorative tool prior to experiments, which is useful for rational design of new drug delivery systems.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Adriana Gregorova ◽  
Michal Machovsky ◽  
Rupert Wimmer

Poly(lactic acid) was filled with 20 wt% of the three mineral fillers Mica, Zeolite, and Vansil, differing in the particle shape and surface area. Viscoelastic properties of unfilled and filled composites were investigated via dynamic mechanical analysis, while filler and fracture surface morphology of the composites was analysed through scanning electron microscopy. Results demonstrate the relationships between viscoelastic damping behaviour of filled PLA composites and the filler distribution in the PLA matrix. Both damping reduction and scanning electron microscope analysis revealed that Zeolite was better distributed in the poly(lactic acid) matrix than the other used fillers Mica and Vansil. The interfacial filler/matrix adhesion has again proved to be the key factor determining thermal and mechanical properties of reinforced composite material.


2011 ◽  
Vol 131 (5) ◽  
pp. 395-400 ◽  
Author(s):  
Toru Oi ◽  
Katsuyoshi Shinyama ◽  
Shigetaka Fujita

2014 ◽  
Vol 134 (4) ◽  
pp. 237-242
Author(s):  
Naru Matsugasaki ◽  
Katsuyoshi Shinyama ◽  
Shigetaka Fujita

2020 ◽  
Vol 62 (6) ◽  
pp. 732-743
Author(s):  
Chi-Hui Tsou ◽  
Jipeng Guo ◽  
Ji-Ang Lei ◽  
Manuel Reyes De Guzman ◽  
Maw-Cherng Suen
Keyword(s):  

2019 ◽  
Vol 821 ◽  
pp. 89-95
Author(s):  
Wanasorn Somphol ◽  
Thipjak Na Lampang ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
...  

Poly (lactic acid) or PLA was reinforced by nanocellulose and polyethylene glycol (PEG), which were introduced into PLA matrix from 0 to 3 wt.% to enhance compatibility and strength of the PLA. The nanocellulose was prepared by TEMPO-mediated oxidation from microcrystalline cellulose (MCC) powder and characterized by TEM, AFM, and XRD to reveal rod-like shaped nanocellulose with nanosized dimensions, high aspect ratio and high crystallinity. Films of nanocellulose/PEG/PLA nanocomposites were prepared by solvent casting method to evaluate the mechanical performance. It was found that the addition of PEG in nanocellulose-containing PLA films resulted in an increase in tensile modulus with only 1 wt% of PEG, where higher PEG concentrations negatively impacted the tensile strength. Furthermore, the tensile strength and modulus of nanocellulose/PEG/PLA nanocomposites were higher than the PLA/PEG composites due to the existence of nanocellulose chains. Visual traces of crazing were detailed to describe the deformation mechanism.


2016 ◽  
Vol 107 ◽  
pp. 333-366 ◽  
Author(s):  
E. Castro-Aguirre ◽  
F. Iñiguez-Franco ◽  
H. Samsudin ◽  
X. Fang ◽  
R. Auras

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