Poly(lactic acid)/Graphene Nanocomposites Prepared via Solution Blending Using Chloroform as a Mutual Solvent

2011 ◽  
Vol 11 (9) ◽  
pp. 7813-7819 ◽  
Author(s):  
Yanhua Chen ◽  
Xiayin Yao ◽  
Xufeng Zhou ◽  
Zhijuan Pan ◽  
Qun Gu
Keyword(s):  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Graphene Nanocomposites ◽  
Solution Blending

Preparation and Isothermal Crystallization Behavior of Poly(lactic acid)/Graphene Nanocomposites

2011 ◽  
Vol 284-286 ◽  
pp. 246-252 ◽  
Author(s):  
Yan Hua Chen ◽  
Xia Yin Yao ◽  
Zhi Juan Pan ◽  
Qun Gu
Keyword(s):  
Lactic Acid ◽  
Isothermal Crystallization ◽  
Graphene Nanosheets ◽  
Nucleating Agent ◽  
Optical Microscope ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Avrami Model ◽  
Graphene Nanocomposites ◽  
Solution Blending

Poly(lactic acid) (PLA)/graphene nanocomposites were prepared by solution blending using chloroform as a mutual solvent. Transmission electron microscopy (TEM) was used to examine the quality of the dispersion of graphene in the PLA matrix. The isothermal crystallization behaviors of PLA and PLA/graphene nanocomposites were investigated by differential scanning calorimetry (DSC). The isothermal crystallization kinetics were analyzed by Avrami model based on the DSC data. The results showed that the well dispersed graphene nanosheets could act as a heterogeneous nucleating agent and lead to an acceleration of crystallization during the PLA isothermal crystallization process. According to the Arrhenius equation, the activation energies were found to be -106.9 and -46.6 kJ/mol for pure PLA and PLA/0.1 wt % graphene nanocomposite, respectively. The crystal morphology were characterized with polarizing optical microscope (POM).

Non-isothermal crystallization kinetics of poly (lactic acid)/graphene nanocomposites

2013 ◽  
Vol 33 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Yanhua Chen ◽  
Xiayin Yao ◽  
Qun Gu ◽  
Zhijuan Pan
Keyword(s):  
Lactic Acid ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Graphene Nanocomposites ◽  
Solution Blending ◽  
Transmission Electron ◽  
Graphene Nanocomposite

Abstract Poly(lactic acid) (PLA)/graphene nanocomposites were prepared by solution blending and the dispersibility of graphene in the PLA matrix was examined by transmission electron microscopy (TEM). The non-isothermal crystallization behaviors of pure PLA and PLA/graphene nanocomposites from the melt were investigated by differential scanning calorimetry (DSC). The results showed that the graphene could play a role as a heterogeneous nucleating agent during the non-isothermal crystallizing process of PLA, and accelerate the crystallization rate. The non-isothermal crystallizing data were analyzed with the Avrami, Ozawa and Mo et al. models and the crystallization parameters of the samples were obtained. It is demonstrated that the combination of the Avrami and Ozawa models developed by Mo et al. was successful in describing the non-isothermal crystallization process for pure PLA and its nanocomposite. According to the Kissinger equation, the activation energies were found to be -154.3 and -179.5 kJ/mol for pure PLA and PLA/0.1 wt% graphene nanocomposite, respectively. Furthermore, the spherulite growth behavior was investigated by polarized optical microscopy (POM) and the results also supported the DSC data.

scholarly journals Fracture Toughness Improvement of Poly(lactic acid) Reinforced with Poly(ε-caprolactone) and Surface-Modified Silicon Carbide

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jie Chen ◽  
Tian-Yi Zhang ◽  
Fan-Long Jin ◽  
Soo-Jin Park
Keyword(s):  
Fracture Toughness ◽  
Silicon Carbide ◽  
Lactic Acid ◽  
Poly Lactic Acid ◽  
External Energy ◽  
Solution Blending ◽  
Blending Method ◽  
Sic Whiskers ◽  
Sic Composites ◽  
Surface Modified

In this study, bio-based poly(lactic acid) (PLA)/polycaprolactone (PCL) blends and PLA/PCL/silicon carbide (SiC) composites were prepared using a solution blending method. The surface of the SiC whiskers was modified using a silane coupling agent. The effects of the PCL and SiC contents on the flexural properties, fracture toughness, morphology of PLA/PCL blends, and PLA/PCL/SiC composites were investigated using several techniques. Both the fracture toughness and flexural strength of PLA increased by the introduction of PCL and were further improved by the formation of SiC whiskers. Fracture surfaces were observed by scanning electron microscopy, which showed that the use of PCL as a reinforcing agent induces plastic deformation in the PLA/PCL blends. The SiC whiskers absorbed external energy because of their good interfacial adhesion with the PLA matrix and through SiC-PLA debonding in the PLA/PCL/SiC composites.

Modeling and predicting the tensile strength of poly (lactic acid)/graphene nanocomposites by using support vector regression

2016 ◽  
Vol 30 (10) ◽  
pp. 1650052
Author(s):  
W. D. Cheng ◽  
C. Z. Cai ◽  
Y. Luo ◽  
Y. H. Li ◽  
C. J. Zhao
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Support Vector Regression ◽  
Process Parameters ◽  
Poly Lactic Acid ◽  
Percentage Error ◽  
Support Vector ◽  
Graphene Nanocomposites ◽  
Absolute Percentage Error ◽  
Rsm Model

According to an experimental dataset under different process parameters, support vector regression (SVR) combined with particle swarm optimization (PSO) for its parameter optimization was employed to establish a mathematical model for prediction of the tensile strength of poly (lactic acid) (PLA)/graphene nanocomposites. Four variables, while graphene loading, temperature, time and speed, were employed as input variables, while tensile strength acted as output variable. Using leave-one-out cross validation test of 30 samples, the maximum absolute percentage error does not exceed 1.5%, the mean absolute percentage error (MAPE) is only 0.295% and the correlation coefficient [Formula: see text] is as high as 0.99. Compared with the results of response surface methodology (RSM) model, it is shown that the estimated errors by SVR are smaller than those achieved by RSM. It revealed that the generalization ability of SVR is superior to that of RSM model. Meanwhile, multifactor analysis is adopted for investigation on significances of each experimental factor and their influences on the tensile strength of PLA/graphene nanocomposites. This study suggests that the SVR model can provide important theoretical and practical guide to design the experiment, and control the intensity of the tensile strength of PLA/graphene nanocomposites via rational process parameters.

Polylactic Acid/Impact Modifier Blends

2012 ◽  
Vol 486 ◽  
pp. 406-411 ◽  
Author(s):  
Nantharat Phruksaphithak ◽  
Cholticha Noomhorm
Keyword(s):  
Lactic Acid ◽  
Phase Separation ◽  
Tensile Properties ◽  
Interfacial Adhesion ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Solution Blending ◽  
Impact Modifier ◽  
Poly Ethylene ◽  
Poly Acrylonitrile

The effects of four impact modifiers: natural rubber (NR), poly (cis-1,4-isoprene) (IR), poly (acrylonitrile-co-butadiene) (NBR) and poly (ethylene-co-vinyl acetate) (PEVA), on the morphology, thermal and tensile properties by solution blending of poly (lactic acid) and 5 and 10 wt% impact modifier were investigated. Results showed that Youngs modulus and T.S. at break decreased in all PLA/impact modifier blends. In addition, Youngs modulus in all blends and T.S. at break in PLA/NR, PLA/IR and PLA/NBR blends was not significantly affected by the type and content of impact modifiers in the blends, but T.S. at break in PLA/PEVA blends was decreased by increasing the PVEA content from 5 wt% to 10 wt%. By contrast, the elongation at break significantly increased in all PLA/impact modifier blends and only PLA/NBR blends was affected by the content of impact modifier. Finally, the increase in ductility of all PLA/impact modifier blends confirmed the toughening capability of all impact modifiers. Thus, it is evident from tensile properties obtained indicated that PLA/impact modifier blends exhibit greater flexibility with all impact modifiers. Phase separation morphology of dispersion of impact modifier in PLA matrix indicating poor interfacial adhesion was observed. Tgand Tmof PLA/impact modifier blends exhibited almost the same as pure PLA, this suggested that there was no molecular interaction between PLA and impact modifiers, therefore, the PLA/impact modifier blends were immiscible.

scholarly journals SIFAT POLIMER DAN KEMAMPUAN TERBIODEGRADASI BLEND BIODEGRADABLE POLYMER POLI (L-ASAM LAKTAT) (PLLA)

REAKTOR ◽  
2014 ◽  
Vol 15 (2) ◽  
pp. 79
Author(s):  
Johnner P Sitompul ◽  
Rizki Insyani ◽  
Hyung Woo Lee
Keyword(s):  
Lactic Acid ◽  
Polymer Blend ◽  
Enzymatic Degradation ◽  
Mechanical Performance ◽  
Poly Lactic Acid ◽  
Ir Absorption ◽  
Hydrogen Bond Interaction ◽  
Solution Blending ◽  
Blending Method ◽  
Degradation Test

 Poly(D,L-lactic acid) (PDLLA) and poly(ethylene glycol) (PEG) was used to modify mechanical and biodegradability properties of poly(L-lactic acid) (PLLA) through solution blending method using solvent mixture of dichloromethane-ethanol. Polymer samples were then characterized using FTIR, DSC, UTM, and enzymatic degradation test. FTIR spectrum of pure PLLA showed specific IR absorption peaks at wavenumber of 3504 cm-1 (-OH), 1757 cm-1 (-C=O), and 1381 cm-1 (-CH3 symmetric). Further, polymer blend samples showed absorption peak shifts at 1755 cm-1 and 1382 cm-1 for PLLA/PDLLA due to stereocomplex interaction and at 3429 cm-1 due to hydrogen bond interaction. DSC results showed that there was melting temperature depression for all polymer blend samples compared to pure PLLA with increasing of either PDLLA or PEG composition. In PLLA/PDLLA, two melting points were discovered because of homocrystallite and stereocomplex phase formation. While PLLA/PEG samples showed increasing crystallinity to 69% at 20%-wt PEG composition. Mechanical analysis showed that 10%-wt of PDLLA addition in PLLA produced better mechanical performance than pure PLLA while 20%-wt of PEG addition showed highest elongation at break with the value of 89%. Polymer blend samples were degradable during enzymatic degradation test represented by percent weight loss with maximum value of 21% for PLLA/PEG sample. Keywords: polymer properties, solution-blending, Poly(lactic acid), polymer blend, enzymatic degradation

Non-isothermal crystallization kinetics assessment of poly(lactic acid)/graphene nanocomposites

2017 ◽  
Vol 26 (5) ◽  
pp. 377-389 ◽  
Author(s):  
Pedram Manafi ◽  
Ismaeil Ghasemi ◽  
Mohammad Reza Manafi ◽  
Parvin Ehsaninamin ◽  
Farzaneh Hassanpour Asl
Keyword(s):  
Lactic Acid ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Poly Lactic Acid ◽  
Isothermal Crystallization Kinetics ◽  
Graphene Nanocomposites
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