The effect of nanoparticles shape on the mechanical properties of poly lactic acid matrix

2021 ◽  
pp. 009524432098816
Author(s):  
Sajjad Daneshpayeh ◽  
Faramarz Ashenai Ghasemi ◽  
Ismail Ghasemi

In this research, mechanical properties of poly lactic acid (PLA)-based nanocomposites were investigated. The nanocomposites were fabricated by adding of three types of nano-materials including multi-walled carbon nanotubes (MWCNT), carbon black (CB) nanoparticles and graphene nano-platelets (GnPs) in four levels from 0 to 3 wt.% to PLA matrix by an internal mixer. Tensile and impact tests were performed to obtain the mechanical properties of nanocomposites. Moreover, field-emission scanning electron microscopy (FESEM) was used to observe the state of nano-fillers dispersion. The FESEM images showed that CB nanoparticles and MWCNT are well distributed in the matrix, but that GnPs are agglomerated. The results of the tensile tests showed that the addition of MWCNT and CB nanoparticles increased the tensile strength by 36% and 76% and the elastic modulus by 10% and 68%, respectively. Also, the presence of all three types of carbon fillers at low loading increased the elongation at break of PLA matrix, and this increase was more significant for GnPs by 55% in the 1 wt.% loading. Finally, the PLA polymer become more brittle with the addition of nanotubes and nano-platelets, and its impact strength was reduced. While, the CB nanoparticles increased the absorbing energy and impact strength.

2019 ◽  
Vol 9 (3) ◽  
pp. 469 ◽  
Author(s):  
Todor Batakliev ◽  
Ivanka Petrova-Doycheva ◽  
Verislav Angelov ◽  
Vladimir Georgiev ◽  
Evgeni Ivanov ◽  
...  

Poly(lactic acid)/graphene and poly(lactic acid)/carbon nanotube nanocomposites were prepared by an easy and low-cost method of melt blending of preliminary grinded poly(lactic acid) (PLA) with nanosized carbon fillers used as powder. Morphological, structural and mechanical properties were investigated to reveal the influence of carbon nanofiller on the PLA–based composite. The dependence of tensile strength on nanocomposite loading was defined by a series of experiments over extruded filaments using a universal mechanical testing instrument. The applying the XRD technique disclosed that compounds crystallinity significantly changed upon addition of multi walled carbon nanotubes. We demonstrated that Raman spectroscopy can be used as a quick and unambiguous method to determine the homogeneity of the nanocomposites in terms of carbon filler dispersion in a polymer matrix.


2017 ◽  
Vol 54 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Maria Adina Vulcan ◽  
Celina Damian ◽  
Paul Octavian Stanescu ◽  
Eugeniu Vasile ◽  
Razvan Petre ◽  
...  

This paper deals with the synthesis of polyurea and its use as polymer matrix for nanocomposites reinforced with multi-walled carbon nanotubes (MWCNT). Two types of materials were obtained during this research, the first cathegory uses the polyurea as matrix and the second one uses a mixture between epoxy resin and polyurea. The nanocomposites were characterized by Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM) and Tensile Tests .The elastomeric features of nanocomposites were highlighted by the results which showed low value of Tg. Also higher thermal stability with ~40oC compared with commercial products (M20) were observed, but lower mechanical properties compared to neat polyurea.


2014 ◽  
Vol 775-776 ◽  
pp. 24-28
Author(s):  
Taciana Regina de Gouveia Silva ◽  
Bartira Brandão da Cunha ◽  
Pankaj Agrawal ◽  
Edcleide Maria Araújo ◽  
Tomás Jefférson Alves de Mélo

In this work, the effect of the PCL content and E-GMA compatibilizer on the mechanical properties and morphology of poly (lactic acid) - PLA/ poly (ε-caprolactone)-PCL blends was investigated. The results of the mechanical properties showed that there was a reduction in the elastic modulus and tensile strength when PCL was added to PLA. The decrease in the modulus was more pronounced when the PCL content was increased from 10 to 20% (wt). The PLA/PCL/E-GMA blend showed the lower modulus and tensile strength. This blend also presented the higher elongation at break and impact strength. The morphology analysis by SEM showed that the PLA/PCL blends where characterized by lack of adhesion between the PLA and PCL phases. The presence of E-GMA in the PLA/PCL/E-GMA blend improved the adhesion between the PLA and PCL phases.Keywords: poly (latic acid); poly (ε-caprolactone); polymer blends; compatibilizer


Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2861
Author(s):  
Zhi-Jun Chen ◽  
Chi-Hui Tsou ◽  
Meng-Lin Tsai ◽  
Jipeng Guo ◽  
Manuel Reyes De Guzman ◽  
...  

Adding natural biomass to poly(lactic acid) (PLA) as a reinforcing filler is a way to change the properties of PLA. This paper is about preparing PLA/biomass composites by physically melting and blending Chinese Spirits distiller’s grains (CSDG) biomass and PLA to optimize the composite performance. Composites of modified PLA (MPLA) with varying amounts of CSDG were also prepared by the melt-mixing method, and unmodified PLA/CSDG composites were used as a control group for comparative analysis. The functional groups of MPLA enhanced the compatibility between the polymer substrate and CSDG. The composite water vapor/oxygen barrier and mechanical properties were studied. It was found that the barrier and mechanical properties of MPLA/CSDG composites were significantly improved. SEM was adopted to examine the tensile section structure of the composites, and the compatibility between the filler and the matrix was analyzed. An appropriate amount of CSDG had a better dispersibility in the matrix, and it further improved the interfacial bonding force, which in turn improved the composite mechanical properties. X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry were conducted to determine the crystalline properties and to analyze the stability of the composites. It was found that the CSDG content had a significant effect on the crystallinity. Barrier and biodegradation mechanisms were also discussed.


2015 ◽  
Vol 35 (8) ◽  
pp. 753-764 ◽  
Author(s):  
Rong-yuan Chen ◽  
Wei Zou ◽  
Hai-chen Zhang ◽  
Gui-zhen Zhang ◽  
Zhi-tao Yang ◽  
...  

Abstract Poly(lactic acid) (PLA)/polypropylene (PP) blends with different weight fractions were prepared by a novel vane extruder. The mechanical properties, morphology, crystallization behavior and thermal stability of the blends were investigated. The tensile strength, flexural strength and elongation at break decreased nonlinearly when the PP content was not more than 50 wt% and then increased with an increase in the PP content. The flexural modulus decreased with increasing PP weight fraction. The PLA/PP 90:10 blend exhibited the optimum impact strength. Scanning electron microscopy measurements revealed that the PLA/PP blends were immiscible. Phase separation occurred significantly at a blend ratio of 50:50. Regarding the PLA/PP 90:10 blend, the mean diameter of the disperse-phase PP particles was the smallest at 1.11 μm. Differential scanning calorimetry measurements showed that low content of PP enhanced the crystallization of PLA. The PLA component in the blends impeded the crystallization of PP when PP was used as the matrix. The thermogravimetric analysis measurement involved a two-step decomposition process of the blends. The thermal resistance of the blends was improved by compounding with PP. As compatibilizers, both the maleic anhydride-grafted PP and the ethylene/n-butyl acrylate/glycidyl methacrylate terpolymer helped improve the mechanical properties, crystallization property and thermal resistance of the PLA/PP blends.


2018 ◽  
Vol 773 ◽  
pp. 51-55
Author(s):  
Jasmine Pongkasem ◽  
Saowaroj Chuayjuljit ◽  
Phasawat Chaiwutthinan ◽  
Amnouy Larpkasemsuk ◽  
Anyaporn Boonmahitthisud

In this study, poly(lactic acid) (PLA) was melt mixed with three weight percentages (10–30wt%) of ethylene vinyl acetate copolymer (EVA) in an internal mixer, followed by a compression molding. According to a better combination of mechanical properties, the 90/10 (w/w) PLA/EVA was selected for preparing hybrid nanocomposites with three loadings (1, 3 and 5 parts per hundred of resin , phr) of poly(methyl methacrylate)-encapsulated nanosilica (PMMA-nSiO2). The nanolatex of PMMA-nSiO2 was synthesized via in situ differential microemulsion polymerization. The obtained PMMA-nSiO2 showed a core-shell morphology with nSiO2 as a core and PMMA as a shell, having an average diameter of 43.4nm. The influences of the EVA and PMMA-nSiO2 on the impact strength and the tensile properties of the PLA/EVA nanocomposites were studied and compared. It is found that the impact strength and the tensile properties of the 90/10 (w/w) PLA/EVA were improved with the appropriate amounts of the EVA and PMMA-nSiO2.


Inventions ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 21 ◽  
Author(s):  
Miho Suzuki ◽  
Asahi Yonezawa ◽  
Kohei Takeda ◽  
Akira Yamada

A fused filament fabrication (FFF) 3D printer is a simple device capable of manufacturing three-dimensional structures in a series of easy steps. Commercial-level FFF 3D printers have spread rapidly in many fields in recent years. Poly(lactic acid) (PLA) is a biodegradable thermoplastic polymer used as a typical printing medium for FFF 3D printers. The FFF printer constructs an object with melted polymer extruded from a tiny scanning nozzle. The mechanical properties of FFF 3D structures printed with different scan patterns can therefore vary in accordance with the directions from which forces act upon them. The nozzle scan pattern also influences the deterioration of the mechanical properties of the structures in accordance with the degradation caused by the hydrolysis of PLA. In this study we conducted tensile tests to evaluate the strength characteristics of 3D printed test pieces formed from PLA using four different scan patterns: parallel, vertical, parallel-and-vertical, and cross-hatched at opposing diagonal angles to the tensile direction. We also formed test pieces by an injection molding method using the same material, for further comparison. We evaluated the deterioration of the test pieces after immersing them in saline for certain periods. After the test pieces formed by different nozzle scan patterns were immersed, they exhibited differences in the rates by which their maximum tensile stresses deteriorated and their masses increased through water uptake. The influences of the scan patterns could be classified into two types: the unidirectional scan pattern influence and bidirectional scan pattern influence. The data obtained in this research will be applied to structural design when the FFF 3D printer is employed for the fabrication of structures with PLA filament.


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