Reactive compatibilization of biodegradable PLA/TPU blends via hybrid nanoparticle

In this study, the compatibilization effects of triglycidylisobutyl polyhedral oligomeric silsesquioxane (TEpPOSS) on biodegradable poly(lactic acid) (PLA)/thermoplastic polyurethane (TPU) blends were investigated. All blends were prepared via melt blending and PLA/TPU (80/20, 70/30, 50/50 wt%) ratio was selected as the experimental parameter. In order to predict the selective localization of TEpPOSS thermodynamically, wetting coefficient were determined by means of surface energy measurements. Morphological analyses were carried out by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Moreover, rheological, mechanical, thermomechanical and thermal properties of the blends were performed via rheometer, universal tensile tester, dynamic mechanic analyses and differential scanning calorimeter (DSC), respectively. Morphological test results revealed that TEpPOSSs were mostly located at the interfaces of the PLA and TPU phases. According to the rheological studies, the interfacial interactions between PLA and TPU were improved with the addition of TEpPOSS, which resulted from the potential reactions between epoxy-carboxylic acid and/or epoxy-hydroxyl functional groups. The addition of TEpPOSS enhanced the mechanical properties of PLA/TPU blends. DSC test results revealed a decrease in the glass transition temperatures of PLA in the presence of TEpPOSS, which was an another indication of improved compatibility between PLA and TPU.

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Buckypaper/DYAD/Buckypaper and Buckypaper/DYAD/ (polyaniline/multiwalled carbon nanotube) composite sensors: Preparation and damping properties characterization

Journal of Composite Materials ◽

10.1177/0021998317725160 ◽

2017 ◽

Vol 52 (11) ◽

pp. 1457-1464

Author(s):

Weiwei Lin ◽

Yonatan Rotenberg ◽

Hadi Fekrmandi ◽

Cesar Levy

Keyword(s):

Electron Microscopy ◽

Carbon Nanotube ◽

Damping Ratio ◽

Multiwalled Carbon Nanotube ◽

Layer By Layer ◽

Test Results ◽

Multiwalled Carbon ◽

Transmission Electron ◽

Nanotube Composites ◽

Matrix Free

Buckypaper/DYAD/Buckypaper and Buckypaper/DYAD/(polyaniline/multiwalled carbon nanotube) composites films were made by frit compression method and layer-by-layer attachment method. Transmission electron microscopy and scanning electron microscopy were used to study the morphology properties of polyaniline/multiwalled carbon nanotube and the results showed that carbon nanotubes were well dispersed in the polymer matrix. Free vibration test results showed that the double-sided attachment of the sensor had higher damping ratio values than single-sided attachment. Also, damping ratios were higher when the composite sensor was placed at the beam's clamped end. Furthermore, the Buckypaper/DYAD/(polyaniline/multiwalled carbon nanotube) combination exhibited higher damping ratios than the other cases tested. Thus, these samples have the potential of being simultaneously strain sensors and dampers.

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Improving the Damping Properties of Nanocomposites by Monodispersed Hybrid POSS Nanoparticles: Preparation and Mechanisms

Polymers ◽

10.3390/polym11040647 ◽

2019 ◽

Vol 11 (4) ◽

pp. 647 ◽

Cited By ~ 5

Author(s):

Wei Wei ◽

Yingjun Zhang ◽

Meihua Liu ◽

Yifan Zhang ◽

Yuan Yin ◽

...

Keyword(s):

Electron Microscopy ◽

Damping Factor ◽

Damping Properties ◽

Molecular Weights ◽

Organic Hybrid ◽

Transmission Electron ◽

The Matrix ◽

Movement Ability ◽

Tan Δ ◽

Oligomeric Silsesquioxane

In this work, a series of heptaphenyl siloxane trisilanol/polyhedral oligomeric silsesquioxane (T7-POSS) modified by polyols with different molecular weights were synthesized into liquid-like nanoparticle–organic hybrid materials using the grafted-from method. All grafted POSS nanoparticles changed from solid powders to liquid at room temperature. Polyurethane (PU) nanocomposites with POSS contents ranging from 1.75 to 9.72 wt % were prepared from these liquefied polyols-terminated POSS with polyepichlorohydrin (POSS–PECH). Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize the morphology of the POSS–PECH/PU nanocomposites. The results showed that the polyol-terminated POSS particles overcame the nanoagglomeration effect and evenly disperse in the polymeric matrix. The damping factor (tan δ) of resultant nanocomposites increased from 0.90 to 1.16, while the glass transition temperature decreased from 15.8 to 9.4 °C when POSS contents increased from 0 to 9.75 wt %. The gel content, tensile strength and Fourier transform infrared (FTIR) analyses demonstrated that the molecular thermal movement ability of the polyurethane (PU) matrix increased with increasing POSS hybrid content. Therefore, the improvement of the damping properties of the composites was mainly due to the friction-related losses occurring in the interface region between the nanoparticles and the matrix.

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Preparation of Al2O3/Al-Si Composites by In Situ Reaction of Fe2O3+MnO2/Al System

Materials Science Forum ◽

10.4028/www.scientific.net/msf.816.48 ◽

2015 ◽

Vol 816 ◽

pp. 48-53

Author(s):

Jing Zhang ◽

Hua Shun Yu ◽

Xin Ting Shuai ◽

Hong Mei Chen ◽

Guang Hui Min

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Electron Probe ◽

Room Temperature ◽

Manganese Content ◽

Hardness Test ◽

Test Results ◽

Electron Probe Micro Analyzer ◽

Transmission Electron ◽

Polygonal Shape

Al2O3 particles reinforced ZL109 composites were prepared by in-situ reaction between Fe2O3+MnO2 and Al in this paper. The influence of ratio of Mn to Fe on the morphologies of Al-Si-Mn-Fe phase and mechanical properties of the composites was investigated. The microstructure was studied by electron probe micro-analyzer (EPMA) and transmission electron microscopy (TEM). The results show that the Al2O3 particles displaced by the Fe2O3+MnO2/Al system are in nanosize. The acicular Al-Si-Fe phases change from acicular to polygonal shape and become smaller with the increase manganese content. The hardness test results have no big difference on the composites. However, the ultimate tensile strength at room temperature and 350°C enhance evidently with the increasing of Mn/Fe.

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Structure and Magnetic Properties of the Co-Ni Alloy Nanowires Prepared by AC Electrodeposition

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.787.372 ◽

2013 ◽

Vol 787 ◽

pp. 372-375 ◽

Cited By ~ 1

Author(s):

X. Wen ◽

Y. Zhang ◽

X.X. Zhang ◽

G.H. Yue ◽

D.L. Peng

Keyword(s):

Electron Microscopy ◽

Magnetic Measurements ◽

Porous Alumina ◽

Test Results ◽

X Ray Diffraction ◽

Transmission Electron ◽

Anodic Porous Alumina ◽

Ni Alloy ◽

Axis Parallel ◽

Alloy Nanowires

Ordered Co-Ni nanowires have been fabricated by alternating current (AC) electrodeposition method using anodic porous alumina as a template. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) test results reveal that the samples are polycrystalline with uniform diameters around 50 nm and lengths up to several micrometers. X-ray diffraction (XRD) pattern indicate the crystalline structure change from fcc to hcp as the Co composition increasing. Magnetic measurements show that the nanowires have high magnetic anisotropy with their easy axis parallel to the nanowire arrays. The coercivity (Hc) and squareness (Mr/Ms) are found to increase with the increase of ferromagnetic Co component.

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Compatibilization and Toughening of Biodegradable Poly (Lactic Acid) / Cellulose Acetate Films by Polyamide Amine Dendrimers

10.21203/rs.3.rs-755422/v1 ◽

2021 ◽

Author(s):

Yansong Huang ◽

Yu juan Jin ◽

Bo Wang ◽

Huafeng Tian ◽

Yunxuan Weng ◽

...

Keyword(s):

Cellulose Acetate ◽

Oxygen Permeability ◽

Pamam Dendrimer ◽

Poly Lactic Acid ◽

Test Results ◽

Excellent Performance ◽

Blend Films ◽

Biodegradable Poly ◽

Green Packaging ◽

Overall Performance

Abstract Due to the poor compatibility caused by the large difference in hydrophilicity and interface between polylactic acid (PLA) and cellulose acetate (CA), the blending of the two materials is difficult and the application is limited. To solve this problem, a type of polyamide amine (PAMAM) dendrimer was introduced to modify PLA / CA blends in this work. The results showed that PAMAM could improve the compatibility of PLA / CA blends, promote the distribution of CA and crystallization of PLA. At the same time, adding PAMAM could enhance the mechanical properties of the blend material, and the toughness and tear strength were increased by 551% and 141%, respectively. In addition, the incorporation of PAMAM increased hydrophobicity and oxygen permeability of PLA/ CA blends, and the oxygen permeability could be increased by up to 3 orders of magnitude. Degradation test results showed that the blend exhibited good biodegradability. The overall performance of the PLA/ CA blend film was optimal when the content of PAMAM was 3 phr. The biodegradable blend films with excellent performance provided wide application prospect in the food green packaging fields.

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Cryptococcus neoformans: Diagnostic Dilemmas, Electron Microscopy and Capsular Variants

Tropical Medicine and Infectious Disease ◽

10.3390/tropicalmed4010001 ◽

2018 ◽

Vol 4 (1) ◽

pp. 1

Author(s):

Monica Birkhead ◽

Serisha D. Naicker ◽

Nozuko P. Blasich ◽

Ivy Rukasha ◽

Juno Thomas ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Cerebrospinal Fluid ◽

Cryptococcus Neoformans ◽

Control Culture ◽

Test Results ◽

Cryptococcal Antigen ◽

Transmission Electron ◽

Staining Protocol ◽

Capsular Material

Two cases of cryptococcal meningitis went undetected by a cryptococcal antigen (CrAg) lateral flow assay on blood in a reflex CrAg screen-and-treat programme in South Africa, although Cryptococcus neoformans was identified by culturing the cerebrospinal fluid specimens. Further investigations into these discordant diagnostic results included multilocus sequence typing (which showed no mutations in the CAP59 gene) and transmission electron microscopy using a capsule-staining protocol (which revealed a >50% reduction in capsular material in both cases, relative to a control culture). A multi-disciplinary approach for resolving discordant diagnostic test results is recommended.

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The Improvement in Mechanical and Thermal Properties of Biodegradable Poly(Butylene Succinate) (PBS) Nanocomposites with Low Loadings of Graphene Oxide (XGO)

Materials Science Forum ◽

10.4028/www.scientific.net/msf.872.235 ◽

2016 ◽

Vol 872 ◽

pp. 235-241

Author(s):

Achanai Buasri ◽

Udon Kampichit ◽

Panupong Salacharoen ◽

Pouvadon Sangsawee ◽

Vorrada Loryuenyong

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Thermal Properties ◽

Mechanical Test ◽

Mechanical And Thermal Properties ◽

Butylene Succinate ◽

Degradation Temperature ◽

Transmission Electron ◽

Uniform Dispersion ◽

Biodegradable Poly

This research aims to study the physical, mechanical and thermal properties of poly (butylene succinate)/graphene oxide (PBS/XGO) nanocomposites. The polymer nanocomposites were successfully prepared by solution processing in conjunction with compression molding at various contents of XGO from 0-1.0 wt%. The structure, tensile properties and thermal stability of materials have been investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), mechanical test, and thermogravimetric analysis. The results revealed that PBS and XGO could mix with each other homogeneously, and uniform dispersion of XGO in the PBS matrix occurred when the filler content was less than 1.0 wt%. Young′s modulus and degradation temperature (Td) of biopolymer were greatly improved by the addition of a small amount of XGO (1.0 wt%). The nanocomposites have potential application as packing materials.

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Enhanced Tensile Properties of Graphene-Al5083 Composite Prepared by Hot Pressing and Hot Extrusion

Materials Science Forum ◽

10.4028/www.scientific.net/msf.849.424 ◽

2016 ◽

Vol 849 ◽

pp. 424-429

Author(s):

Hai Ping Zhang ◽

Wen Long Xiao ◽

Kei Ameyama ◽

Guo Fu Ji ◽

Ming Juan Yang ◽

...

Keyword(s):

Electron Microscopy ◽

Tensile Strength ◽

Tensile Elongation ◽

Hot Extrusion ◽

Powder Metallurgy Method ◽

Test Results ◽

X Ray Diffraction ◽

Composite Powders ◽

Vacuum Oven ◽

Transmission Electron

Graphene, with outstanding mechanical properties of 1TPa of Young’s modulus and 130GPa of tensile strength, has been considered as an excellent reinforcement in composites. Graphene nanoplates (GNP) reinforced Al5083 alloy composites were successfully fabricated by powder metallurgy method. Flake-like Al5083 powder was firstly added into a GNP-alcohol solution and then dried in vacuum oven at 343 K for 5 h. The composite powders were sintered at 723K under pressure of 300 MPa for 1 h, followed by extrusion at 623 K. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed for microstructure characterization. Al4C3 cannot be observed in the composite, suggesting that there was no reaction occurred between GNP and Al matrix during the processing. Tensile test results revealed that the ultimate tensile strength and tensile elongation of 0.3wt.%GNP/Al5083 composites were 580MPa and 15%, respectively, showing optimal combination of strength and ductility. The relevant strengthening mechanisms of the composites were discussed.

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Compatibilization and Characterization of Polylactide and Biopolyethylene Binary Blends by Non-Reactive and Reactive Compatibilization Approaches

Polymers ◽

10.3390/polym12061344 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1344 ◽

Cited By ~ 1

Author(s):

Jose M. Ferri ◽

Daniel Garcia-Garcia ◽

Emilio Rayón ◽

Maria D. Samper ◽

Rafael Balart

Keyword(s):

Electron Microscopy ◽

Vinyl Acetate ◽

Charpy Test ◽

Binary Blends ◽

Reactive Compatibilization ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Field Emission Electron Microscopy ◽

Microscopic Techniques

In this study, different compatibilizing agents were used to analyze their influence on immiscible blends of polylactide (PLA) and biobased high-density polyethylene (bioPE) 80/20 (wt/wt). The compatibilizing agents used were polyethylene vinyl acetate (EVA) with a content of 33% of vinyl acetate, polyvinyl alcohol (PVA), and dicumyl peroxide (DPC). The influence of each compatibilizing agent on the mechanical, thermal, and microstructural properties of the PLA-bioPE blend was studied using different microscopic techniques (i.e., field emission electron microscopy (FESEM), transmission electron microscopy (TEM), and atomic force microscopy with PeakForce quantitative nanomechanical mapping (AFM-QNM)). Compatibilized PLA-bioPE blends showed an improvement in the ductile properties, with EVA being the compatibilizer that provided the highest elongation at break and the highest impact-absorbed energy (Charpy test). In addition, it was observed by means of the different microscopic techniques that the typical droplet-like structure is maintained, but the use of compatibilizers decreases the dimensions of the dispersed droplets, leading to improved interfacial adhesion, being more pronounced in the case of the EVA compatibilizer. Furthermore, the incorporation of the compatibilizers caused a very marked decrease in the crystallinity of the immiscible PLA-bioPE blend.

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