Processing and MWNT Composition Effects on the Thermal, Electrical and Mechanical Properties of PLA-MWNT Composites

Composite Films ◽

Thermal Characteristics ◽

Casting Process ◽

Multiwall Carbon Nanotube ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Electrical Percolation

This paper investigates the processing and its effects and the effect of multiwall carbon nanotube (MWNT) composition on the thermal, electrical and mechanical properties of polylactide (PLA)-MWNT composites. The composite films were prepared by a solvent casting process using two solvents, chloroform and 1,4-dioxane. The dispersion of the MWNTs in PLA was examined using a scanning electron microscope and was found to be more improved when 1,4-dioxane was used as the solvent as compared to chloroform. The thermal characteristics of the composites were examined on Differential Scanning Calorimetry and Thermo-gravimetric Analysis. Composites prepared using 1,4-dioxane had greater improvements in composite decomposition temperature, glass transition temperature and displayed faster crystallization kinetics. The mechanical properties of the composites were tested in uniaxial tension. Composites prepared using chloroform had a lower modulus than composites prepared using 1,4-dioxane. The electrical AC conductivity of the composites was measured over a broad frequency spectrum. Composites prepared using 1,4-dioxane displayed electrical percolation at 0.5 wt.% MWNT in PLA while percolation was absent in 0.5 wt.% MWNT composites prepared using chloroform.

Biocomposites of Bio-Polyethylene Reinforced with a Hydrothermal-Alkaline Sugarcane Bagasse Pulp and Coupled with a Bio-Based Compatibilizer

Molecules ◽

10.3390/molecules25092158 ◽

2020 ◽

Vol 25 (9) ◽

pp. 2158

Author(s):

Nanci Vanesa Ehman ◽

Diana Ita-Nagy ◽

Fernando Esteban Felissia ◽

María Evangelina Vallejos ◽

Isabel Quispe ◽

...

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Water Absorption ◽

Sugarcane Bagasse ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Cradle To Gate ◽

Bagasse Pulp

Bio-polyethylene (BioPE, derived from sugarcane), sugarcane bagasse pulp, and two compatibilizers (fossil and bio-based), were used to manufacture biocomposite filaments for 3D printing. Biocomposite filaments were manufactured and characterized in detail, including measurement of water absorption, mechanical properties, thermal stability and decomposition temperature (thermo-gravimetric analysis (TGA)). Differential scanning calorimetry (DSC) was performed to measure the glass transition temperature (Tg). Scanning electron microscopy (SEM) was applied to assess the fracture area of the filaments after mechanical testing. Increases of up to 10% in water absorption were measured for the samples with 40 wt% fibers and the fossil compatibilizer. The mechanical properties were improved by increasing the fraction of bagasse fibers from 0% to 20% and 40%. The suitability of the biocomposite filaments was tested for 3D printing, and some shapes were printed as demonstrators. Importantly, in a cradle-to-gate life cycle analysis of the biocomposites, we demonstrated that replacing fossil compatibilizer with a bio-based compatibilizer contributes to a reduction in CO2-eq emissions, and an increase in CO2 capture, achieving a CO2-eq storage of 2.12 kg CO2 eq/kg for the biocomposite containing 40% bagasse fibers and 6% bio-based compatibilizer.

Enhancing the Thermal and Mechanical Characteristics of Polyvinyl Alcohol (PVA)-Hemp Protein Particles (HPP) Composites

International Polymer Processing ◽

10.1515/ipp-2020-3974 ◽

2021 ◽

Vol 36 (2) ◽

pp. 137-143

Author(s):

S. A. Awad

Keyword(s):

Mechanical Properties ◽

Elevated Temperatures ◽

Composite Films ◽

Tensile Tests ◽

Mechanical Analysis ◽

Scanning Calorimetry ◽

Solution Casting Method ◽

Protein Particles

Abstract This paper aims to describe the thermal, mechanical, and surface properties of a PVA/HPP blend whereby the film was prepared using a solution casting method. The improvements in thermal and mechanical properties of HPP-based PVA composites were investigated. The characterization of pure PVA and PVA composite films included tensile tests, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results of TGA and DSC indicated that the addition of HPP increased the thermal decomposition temperature of the composites. Mechanical properties are significantly improved in PVA/HPP composites. The thermal stability of the PVA composite increased with the increase of HPP filler content. The tensile strength increased from 15.74 ± 0.72 MPa to 27.54 ± 0.45 MPa and the Young’s modulus increased from 282.51 ± 20.56 MPa to 988.69 ± 42.64 MPa for the 12 wt% HPP doped sample. Dynamic mechanical analysis (DMA) revealed that at elevated temperatures, enhanced mechanical properties because of the presence of HPP was even more noticeable. Morphological observations displayed no signs of agglomeration of HPP fillers even in composites with high HPP loading.

Nanostructured polyurethane perylene bisimide ester assemblies with tuneable morphology and enhanced stability

Royal Society Open Science ◽

10.1098/rsos.171686 ◽

2018 ◽

Vol 5 (3) ◽

pp. 171686 ◽

Cited By ~ 2

Author(s):

Xiaoxiao Zhang ◽

Tingyuan Gong ◽

Hong Chi ◽

Tianduo Li

Keyword(s):

Self Assembly ◽

Size Control ◽

Gel Permeation Chromatography ◽

Inorganic Materials ◽

Quantum Yields ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Perylene Bisimide

Size control has been successfully achieved in inorganic materials, but it remains a challenge in polymer nanomaterials due to their polydispersity. Here, we report a facile approach to tailor the diameters of polyurethane (PU) nanoparticles (490 nm, 820 nm and 2.1 µm) via perylene bisimide (PBI) assisted self-assembly. The formed morphologies such as spindle, spherical and core–shell structures depend on the ratio of PBI and polymer concentrations. It is shown that the formation of PU nanoparticles is directed by π–π stacking of PBI and the morphology transition is not only affected by the amount of PBI incorporated, but also influenced by solvent, which controls the initial evaporation balance. Furthermore, the prepared PUs exhibit retained optical stability and enhanced thermal stability. The PUs, designed to have conjugated PBI segments in backbones, were synthesized via ring-opening and condensation reactions. Compared with the neat PU, gel permeation chromatography shows narrower molecular weight distribution. Fluorescence spectra and ultraviolet–visible spectra indicate retained maximum emission wavelength of PBI at 574 nm and 5.2% quantum yields. Thermo-gravimetric analysis and differential scanning calorimetry reveal 79°C higher decomposition temperature and 22°C higher glass transition temperature. This study provides a new way to fabricate well-defined nanostructures of functionalized PUs.

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

Electro-mechanical and thermal characteristics of silver-electroded ionic polymer–metal composite actuator

10.1177/0954406211424979 ◽

2011 ◽

Vol 226 (6) ◽

pp. 1427-1436 ◽

Cited By ~ 2

Author(s):

D K Biswal ◽

D Bandopadhya ◽

S K Dwivedy

Keyword(s):

Thermal Characteristics ◽

Experimental Investigations ◽

Gravimetric Analysis ◽

Metal Composite ◽

Ionic Polymer Metal Composite ◽

Scanning Calorimetry ◽

Ionic Polymer ◽

Base Polymer ◽

Polymer Metal

The proposed work is in line with the evaluation of electro-mechanical and thermal characteristics of silver-electroded ionic polymer–metal composite (IPMC). IPMCs are fabricated first using Nafion-117 as base polymer and non-precious metal silver as surface electrode by chemical decomposition method. Several testings are performed on fabricated IPMC to evaluate its thermo-mechanical and micro-structural properties. The characteristics of the electrode layer and deposited particles on IPMC surface are studied using scanning electron microscope. The bending experiment of the actuator is conducted by applying direct current potential and the tip displacement measured. Thermo-gravimetric analysis and differential scanning calorimetry test are carried out, and thermal stability of the actuator is investigated. The crystal structure of IPMC is investigated by X-ray diffraction analysis. Micro-tensile test of the specimen is carried out to ascertain the stress–strain relationship and comparison is made with the base polymer, Nafion. The experimental investigations, characterization, and performance of the IPMC demonstrate its effectiveness to be used as actuator and artificial muscle materials.

Experimental Investigation of Kevlar KM2Plus Nano-Reinforced Laminated Composite Thermo-Mechanical Properties

Volume 6A: Materials and Fabrication ◽

10.1115/pvp2016-63857 ◽

2016 ◽

Cited By ~ 2

Author(s):

Abdel-Hamid I. Mourad ◽

Omar G. Ayad ◽

Ashfakur Rahman ◽

Ali Hilal-Alnaqbi ◽

Basim I. Abu-Jdayil

Keyword(s):

Mechanical Properties ◽

Laminated Composite ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Thermo Gravimetric ◽

Three Point Bending ◽

Multi Walled Carbon Nanotube ◽

Thermal Stability Of

This work is concerned with the synthesis and characterization of Multi-Walled Carbon Nanotube (MWCNT) reinforced Kevlar KM2Plus composites with various MWCNT contents (0.2, 0.3, 0.4, 0.5, 0.6, and 0.8 wt. %), by the wet lay-up technique. These samples were experimentally investigated for their thermo-mechanical properties using Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), tensile testing and three-point bending techniques. The mechanical properties showed remarkable improvement with increasing MWCNT wt.% up to certain content. The results revealed that the addition of MWCNT fillers has no significant effect on the thermal stability of the composites.

Synthesis, Characterization and Isothermal Crystallization Kinetics of Poly(Dodecamethylene Terephthalamide)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.284-286.1894 ◽

2011 ◽

Vol 284-286 ◽

pp. 1894-1900

Author(s):

Kai Feng Li ◽

Peng Fu ◽

Chuan Lin Liu ◽

Qing Xiang Zhao ◽

Min Ying Liu

Keyword(s):

Crystallization Kinetics ◽

Isothermal Crystallization ◽

Aromatic Polyamide ◽

Proton Nuclear Magnetic Resonance ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Isothermal Crystallization Kinetics ◽

Kinetics Of

A kind of semi-aromatic polyamide, poly(dodecamethylene terephthalamide) (PA12T) was synthesized via a three-step reaction of terephthalic acid and 1,12-dodecanediamine. The structure of the prepared PA12T was characterized by Fourier transform infrared (FT-IR) spectroscopy and proton nuclear magnetic resonance (1H-NMR). The thermal behaviour of PA12T was determined by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and dynamic mechanical analysis (DMA). Melting temperature (Tm), glass transition temperature (Tg) and decomposition temperature (Td) of PA12T are 311°C, 144°C and 429°C, respectively. Isothermal crystallization kinetics of PA12T have been investigated in the temperature range of 270-280°C using DSC. The activation energies (ΔE) were determined to be -170.4 kJ/mol for the isothermal crystallization processes by the Arrhenius’ methods.

Effect of Radiation-Induced Cross-Linking on Thermal Aging Properties of Ethylene-Tetrafluoroethylene for Aircraft Cable Materials

Materials ◽

10.3390/ma14020257 ◽

2021 ◽

Vol 14 (2) ◽

pp. 257

Author(s):

Xiaodong Zhang ◽

Fei Chen ◽

Zhimin Su ◽

Taiping Xie

Keyword(s):

Mechanical Properties ◽

Electron Beam ◽

Thermal Characteristics ◽

Volume Resistivity ◽

Cross Linking ◽

Gravimetric Analysis ◽

Aging Properties ◽

Radiation Induced ◽

Ethylene Tetrafluoroethylene

The effects of electron beam irradiation on ethylene-tetrafluoroethylene copolymer (ETFE) were studied. Samples were irradiated in air at room temperature by a universal electron beam accelerator for various doses. The effect of irradiation on samples and the cross-linked ETFE after aging were investigated with respect to thermal characteristics, crystallinity, mechanical properties, and volume resistivity using thermo-gravimetric analysis (TGA), differential scanning calorimeter (DSC), universal mechanical tester, and high resistance meter. TGA showed that thermal stability of irradiated ETFE is considerably lower than that of unirradiated ETFE. DSC indicates that crystallinity is altered greatly by cross-link. The analysis of mechanical properties, fracture surface morphology, visco-elastic properties and volume resistivity certify radiation-induced cross-linking is vital to aging properties.

Studies on thermal and degradation kinetics of cellulose micro/nanoparticle filled polylactic acid (PLA) based nanocomposites

Polymers and Polymer Composites ◽

10.1177/0967391120987170 ◽

2021 ◽

pp. 096739112098717

Author(s):

Achal Bhiogade ◽

Murugasamy Kannan

Keyword(s):

Degradation Kinetics ◽

Composite Films ◽

Degree Of Crystallinity ◽

Hydroxyl Group ◽

Poly Lactic Acid ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Kinetics Of ◽

The Degree Of Crystallinity

The aim of this work is to understand the effect of concentration of plasticizer, particle size and wt% of nanoparticles on nanocomposites by fabricating poly lactic acid (PLA) based bio-nanocomposites. The bio-nanocomposites were prepared by a solution casting method with PLA as the matrix, chloroform as solvent and poly ethylene glycol (PEG) as plasticizer. Microcrystalline cellulose (MCC) and cellulose nanocrystal (CNC) were used as reinforcements in 1, 3 and 5 wt% to modify the properties of the bio-nanocomposite. The degradation kinetics of the PLA based composites were determined by using the Coats-Redfern equation over the range of 0-5 wt% of MCC and CNC. Fabricated PLA based composite films were analyzed by differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and field emission scanning electron microscopy (FE-SEM). The analyses showed that the amount of PEG, MCC and CNC affected the degree of crystallinity. DSC results showed that the MCC/CNC content level affected the degree of crystallinity compared to neat PLA. The FTIR showed a free hydroxyl group (−OH) present in the system. The TGA analysis showed that the PLA/MCC3%/ PEG 10% composition had the highest stability compared to the other compositions but less than neat PLA.

Synthesis and Characterization of Porous Polyurethane-Chitosan Blends

Cellular Polymers ◽

10.1177/026248930902800301 ◽

2009 ◽

Vol 28 (3) ◽

pp. 179-191 ◽

Cited By ~ 4

Author(s):

Imelda Olivas-Armendariz ◽

Perla E. García-Casillas ◽

Alberto Martínez-Villafañe ◽

Carlos A. Martinez-Pérez

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Synthesis And Characterization ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Thermo Gravimetric ◽

Chitosan Blends ◽

Scanning Electron

In this work the synthesis and characterization of polyurethane (PU)-chitosan(CH) porous prepared by thermal induced phase separation (TIPS) is described, the obtained products were characterized by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC), evidence of the interaction between both polymers was acquired from infrared spectroscopy. The morphology of the scaffolds was studied by scanning electron microscopy also the mechanical properties were acquired. The results showed that the TIPS technique is appropriate for the production of PU-CH porous materials.

Hydrophilic porous polyimide/β-cyclodextrin composite membranes with enhanced gas separation performance and low dielectric constant

High Performance Polymers ◽

10.1177/0954008317701548 ◽

2017 ◽

Vol 30 (4) ◽

pp. 446-455 ◽

Cited By ~ 8

Author(s):

Zehan Liu ◽

Long Pang ◽

Qing Li ◽

Shulai Zhang ◽

Jing Li ◽

...

Keyword(s):

Mechanical Properties ◽

Contact Angle ◽

Gas Adsorption ◽

Composite Films ◽

Tensile Modulus ◽

Composite Membranes ◽

Separation Performance ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Good Thermal Stability

A series of co-polyimide (PI)/modified β-cyclodextrin (β-CD) composites were successfully fabricated from anhydride-terminated PI and (3-aminopropyl)triethoxysilane-modified β-CD (β-ACD). Co-PI was prepared from 4,4′-oxydianiline, 4,4′-(hexafluoroisopropylidene) diphthalic anhydride, and 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride by chemical imidization. Different amounts of β-ACD (0, 1, 3, 5, and 7 wt%) were introduced into co-PI via strong covalent interactions between the terminal anhydride and amino groups. The structures and properties of the composites were characterized by means of Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermal gravimetric analysis, differential scanning calorimetry, dynamic thermomechanical analysis, mechanical properties tests, and contact angle tests. The results showed that β-ACD was successfully grafted on the PI segment. The composite films showed good thermal stability, glass transition temperatures between 244°C and 254°C, and 10% weight loss at temperatures of 514°C–545°C and 506°C–538°C in nitrogen and air atmosphere, respectively. They also exhibited excellent mechanical properties with tensile strength, tensile modulus, and elongation at break values of 78–111 MPa, 1.14–2.05 GPa, and 8–17%, respectively. All of these values were maximized at a β-ACD content of 1 wt%. The water uptake of the composites films was more than 1%, indicating that the addition of β-ACD can enhance the water absorption of PI films. All of these composite films are porous, and the contact angle indicated that the addition of β-ACD increased the hydrophilicity of the composite film. When the β-ACD doping content reached 7 wt%, the contact angle reached a minimum of 63°. All of the membranes were thermally annealed at 300°C for 1 h, after which gas adsorption tests showed that the composite films have enhanced CO2/CH4 selectivity, which can reach 12.7 (308 K).