scholarly journals Analysis of PLA Composite Filaments Reinforced with Lignin and Polymerised-Lignin-Treated NFC

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2174
Author(s):  
Diana Gregor-Svetec ◽  
Mirjam Leskovšek ◽  
Blaž Leskovar ◽  
Urška Stanković Elesini ◽  
Urška Vrabič-Brodnjak

Polylactic acid (PLA) is one of the most suitable materials for 3D printing. Blending with nanoparticles improves some of its properties, broadening its application possibilities. The article presents a study of composite PLA matrix filaments with added unmodified and lignin/polymerised lignin surface-modified nanofibrillated cellulose (NFC). The influence of untreated and surface-modified NFC on morphological, mechanical, technological, infrared spectroscopic, and dynamic mechanical properties was evaluated for different groups of samples. As determined by the stereo and scanning electron microscopy, the unmodified and surface-modified NFCs with lignin and polymerised lignin were present in the form of plate-shaped agglomerates. The addition of NFC slightly reduced the filaments’ tensile strength, stretchability, and ability to absorb energy, while in contrast, the initial modulus slightly improved. By adding NFC to the PLA matrix, the bending storage modulus (E’) decreased slightly at lower temperatures, especially in the PLA samples with 3 wt% and 5 wt% NFC. When NFC was modified with lignin and polymerised lignin, an increase in E’ was noticed, especially in the glassy state.

2018 ◽  
Vol 186 ◽  
pp. 02001
Author(s):  
Teng-wei Zhu ◽  
Cheng-liang Miao ◽  
Zheng Cheng ◽  
Zhipeng Wang ◽  
Yang Cui ◽  
...  

The influence of the mechanical properties of X70 pipeline steel under different annealing temperature was studied. The corresponding microstructure was investigated by the Field Emission Scanning Electron Microscopy. The results showed that the yield strength and the tensile strength both experienced from rise to decline with the increase of annealing temperature. The grain sizes were coarse and a large amount of cementite precipitated due to preserving temperature above 550 °, which induced matrix fragmentation and deteriorate the -10 ° DWTT Toughness. There were little changes on the microstructure and mechanical properties when the annealing temperature was under 500 °.


2012 ◽  
Vol 729 ◽  
pp. 246-251 ◽  
Author(s):  
Sándor Kling ◽  
Tibor Czigány

The geometry and mechanical properties of solid and hollow carbon fibres were investigated by light-and scanning electron microscopy, and by single fibre tensile tests. The hollowness factor of fibres was determined by their external and internal diameter. The tensile strength was determined by single fibre tensile break tests. It was shown that the bigger the diameter of the fibres the lower the mechanical properties is. It was found that the hollow carbon fibres are suitable for preparation of a self-repairing composite with the advantage over other solutions because of their geometrical and mechanical properties.


2014 ◽  
Vol 1048 ◽  
pp. 36-40
Author(s):  
Wei Lai Chen ◽  
Lin Yan Wan ◽  
Hong Qin

Microstructures and mechanical properties of melt spinning spandex were studied in this article.Cross section and longitudinal surface were observed and analyzed by JSM-5610LV scanning electron microscopy. Q2000 DSC differential scanning calorimeter was used to test the glass transition temperature and melting temperature which indicated glass transition temperature is about 44°C and melting temperature is about 200°C. We employed JSM-5610LV scanning electron microscopy to observe adhesion of melt spinning spandex with nylon filament after different time and temperature processing. It concluded that after 150°C90s、160°C60s、160°C90s、170°C30s heat treatment, the adhesive of melt spinning spandex with nylon is good. At the same time,tensile strength and elastic properties of melt spinning spandex which was processed under different time and temperature were tested, tensile strength and elastic recovery of melt spinning spandex after160°C 90s heat treatment is the best.


2017 ◽  
Vol 264 ◽  
pp. 112-115
Author(s):  
Erfan Suryani Abdul Rashid ◽  
Wageeh Abdulhadi Yehye ◽  
Nurhidayatullaili Muhd Julkapli ◽  
Sharifah Bee O.A. Abdul Hamid

Nanocellulose (NCC) is incorporated into nitrile butadiene rubber (NBR) latex with the composition 0 to 5 phr using dipping method. Mechanical properties of NBR/NCC composites using tensile test was used to characterize their mechanical performance and the fracture surfaces post tensile test were studied. The tensile strength of NBR/NCC composites increase significantly with the addition of nanocellulose. This could be anticipated due to the presence of Van der Waals interaction between hydrophilic natures of nanocellulose with hydrophobic of NBR consequently limits the tearing propagation. The result was supported with the fracture surfaces morphology viewed under Fourier Emission Scanning Electron Microscopy (FESEM).


2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Li Juan

The nanocomposites of polypropylene (PP)/graphene were prepared by melt blending. The effects of the dosage of graphene on the flow and mechanical properties of the nanocomposites were investigated. The morphologies of fracture surfaces were characterized through scanning electron microscopy (SEM). The graphene simultaneous enhanced tensile and impact properties of nanocomposites. A 3.22% increase in tensile strength, 39.8% increase in elongation at break, and 26.7% increase in impact strength are achieved by addition of only 1 wt.% of graphene loading. The morphological behavior indicates the fracture surface of PP/graphene is more rough than that of pure PP.


2019 ◽  
Vol 821 ◽  
pp. 201-205
Author(s):  
Chao Deng ◽  
Xian Gyu Jin

In this work, pulp/lyocell wet-laid paper sheets have been consolidated by hydroentanglement techniques. Scanning electron microscopy has been used to evaluate the structures of wet-laid paper sheets before and after hydroentanglement. Wet tensile strength along longitudinal (preferential) and transverse directions show the effect of hydroentanglement techniques on the mechanical properties of wet-laid paper sheets. In addition, the air permeability and water absorbency properties of materials have been evaluated. The results show that the structures of wet-laid paper sheets become fluffy and fiber entanglements increase after consolidation. The wet tensile strength values of wet-laid paper sheets at the longitudinal and transverse directions are increased by 109.0% and 78.7%, respectively after hydroentanglement. The air permeability and water absorbency of wet-laid paper sheets are increased by 957.6% and 137.0%.


2015 ◽  
Vol 817 ◽  
pp. 192-197
Author(s):  
Xin Zhang ◽  
Ze Hua Wang ◽  
Ze Hua Zhou ◽  
Jian Ming Xu ◽  
Zhao Jun Zhong ◽  
...  

A series of Al-3.2Mg alloys with addition of 0~1.6 wt.% rare earth (Ce and La) were prepared. The microstructure of as-cast Al-3.2Mg alloys was investigated by optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and the tensile strength was measured. The results indicated that the addition of rare earth elements refined grain size and secondary dendrite arm spacing (SDAS), and the tensile strength was affected by means of the second-phase precipitation and the grain boundary. Accordingly, the ductility of Al-3.2Mg alloys reduced with the increasing of RE addition due to the more second-phase formation.


2015 ◽  
Vol 4 (3) ◽  
pp. 23-28
Author(s):  
Fadhilla Asyri ◽  
Kartini Noor Hafni ◽  
A. Haris Simamora

This study aims was to determine the effect of palm oil fuel ash (POFA) composite as filler on the physical and mechanical properties of high impact polystyrene (HIPS) composites. The research methodology included preparation of raw materials, treatment POFA (hydration process of POFA), mixing using tumbler and then extruder, molding composite specimens, and testing. The variables used were weight ratio of HIPS with 140 mesh POFA at 95/5; 92.5/7.5; 90/10. The composites were tested by Fourier Transform Infrared (FTIR), ash content, specific gravity, tensile strength, elongation at break, impact strength, hardness test, and Scanning Electron Microscopy (SEM). The results of FTIR characterization shows the formation of –OH bonding that was suspected as Si-OH or Si-hydrat. Results of physical and mechanical properties of the composites shows that increase of the filler composition in HIPS-POFA composites until the ratio of 90/10, increase the specific gravity to 7.2% of the original, tensile strength did not change significantly to 28.4 MPa, elongation at break decreased to 2.7%, impact strength decreased to 3.183 KJ/m2, and the hardness increased to 110.5, and Scanning Electron Microscopy (SEM) test show the transformation of POFA structure on treated POFA and intercalation between the matrix and POFA.


2017 ◽  
Vol 893 ◽  
pp. 202-206 ◽  
Author(s):  
Qing Lin Li ◽  
Bin Qiang Li ◽  
Jin Bao Li ◽  
Chao Fen Zhang ◽  
Ye Feng Lan

It is well known that Al-Si-Mg alloy can form Chinese script eutectic Mg2Si and large blocky primary Mg2Si phases. In this paper, the microstructures and mechanical properties of cast Al-18Si-10Mg-xEr (x=0, 0.3, 0.5, 0.8 and 1.0 wt.%) alloy were investigated. The as-cast samples were characterized by optical microscopy (OM), scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) with wavelength dispersive spectroscopic (WDS). The results show that the morphology of primary Mg2Si changed from large block or Chinese script-like to fine block with increasing of Er contents from 0.3% to 1.0%., and the morphology of eutectic Si phases transformed into fine coral-like fibrous structure and the size of eutectic Si dramatically decrease. The mechanical properties were researched by tester with different concentration of rare earth Er. It was found that the ultimate tensile strength and hardness increased by 32.1% and 21.4%, respectively.


2008 ◽  
Vol 589 ◽  
pp. 263-267 ◽  
Author(s):  
Balázs Solymossy ◽  
József Gábor Kovács

This paper focuses on the effect of different fiber content on the mechanical properties of specimens with and without weld lines. The effect of three different melt temperatures and holding pressures were also investigated. For the experiments dumbbell shaped standard tensile specimens with and without weld lines were injection molded from PP (TVK’s H116F homopolymer) and short glass fiber (0, 10, 20, 30, 40 wt%). The mechanical properties of these composites were determined by quasi-static (standard tensile testing) and dynamic (Charpy impact test) testing methods and the corresponding weld line factors were calculated. The fracture surfaces were analyzed with the help of scanning electron microscopy (SEM). From the results of the tensile and Charpy-impact tests, it was ascertained that the temperatures and the holding pressures during injection molding did not affect the tensile and impact properties, but fiber length had a major impact on the mechanical properties of this specific composite. By increasing the fiber content, the tensile strength increased until a peak and declined after. Whereas the impact resistance decreased by the increasing fiber content in the whole examination window. Comparing the weld lined and weld line free specimens, it was concluded that weld lines did significantly decrease the tensile strength and impact properties due to the unfavorable fiber orientation beside the weld line which was visualized by scanning electron microscopy.


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