Dispersion characteristics of hydroxyl and carboxyl-functionalized multi-walled carbon nanotubes in polyester nanocomposites

2018 ◽  
Vol 38 (8) ◽  
pp. 759-765
Author(s):  
Muhammad Remanul Islam ◽  
Md. Dalour H. Beg
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Functional Groups ◽  
Unsaturated Polyester ◽  
Group Analysis ◽  
Melting Behavior ◽  
Dispersion Characteristics ◽  
Scanning Calorimetry ◽  
Result Analysis ◽  
Functionalized Mwcnts

Abstract Multi-walled carbon nanotube (MWCNT) reinforced polyester-based composites were prepared by mixed blending in a solvent. Orthophthalic unsaturated polyester was blended individually with different types of non-functionalized and functionalized MWCNTs. Two types of functional groups: hydroxyl (-OH) and carboxyl (-COOH) were introduced with MWCNTs for the nanocomposites. The mechanical properties of the composites, like tensile, three-point bending and impact energy were evaluated. Fourier transform infrared spectroscopy was used for the functional group analysis. The dispersion characteristics of the samples were observed by transmission electron microscopy and field-emission electron microscopy. In addition, the thermal decomposition and melting behavior of the samples was assessed by differential scanning calorimetry and thermogravimetric analysis. The properties were varied due to the variation of the functional groups. The result analysis showed that the entangled agglomerations of hydroxyl-functionalized MWCNTs were destroyed to relatively smaller clusters. The hydroxyl-functionalized MWCNTs were more effective for homogeneous dispersion and contributed for better mechanical properties of the composites, compared to non-functionalized and carboxyl group-functionalized MWCNTs.

scholarly journals Effects of Aging under Stress on Mechanical Properties and Microstructure of EN AW 7075 Alloy

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1142
Author(s):  
S. V. Sajadifar ◽  
P. Krooß ◽  
H. Fröck ◽  
B. Milkereit ◽  
O. Kessler ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Screening Tool ◽  
Precipitation Kinetics ◽  
Scanning Calorimetry ◽  
Aging Precipitation ◽  
Precipitation Processes ◽  
External Stresses ◽  
7075 Alloy ◽  
Effects Of Aging

In the present study, microstructural and mechanical properties of EN AW 7075 following stress-aging were assessed. For this purpose, properties of stress-aged samples were compared with values obtained for conventionally aged counterparts. It is revealed that the strength and hardness of EN AW 7075 can be increased by the presence of external stresses during aging. Precipitation kinetics were found to be accelerated. The effects of conventional and stress-aging on the microstructure were analyzed using synergetic techniques: the differently aged samples were probed by differential scanning calorimetry (DSC) in order to characterize the precipitation processes. DSC was found to be an excellent screening tool for the analysis of precipitation processes during aging of this alloy with and without the presence of external stresses. Furthermore, using electron microscopy it was revealed that an improvement in mechanical properties can be correlated to changes in the morphologies and sizes of precipitates formed.

Research on compatibility and surface of high impact bio-based polyamide

2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Crystallization Behavior ◽  
High Impact ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.

Effects of Thermal Treatment on the Morphology and Properties of CSM/Poly(Urethane-Isocyanurate) Composites Formed by SRIM Process

2008 ◽  
Vol 575-578 ◽  
pp. 941-946
Author(s):  
Hong Yan Tang ◽  
Ji Hui Wang ◽  
Guo Qiang Gao ◽  
Wen Xing Chen
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Treatment Time ◽  
Microphase Separation ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Scanning Electron

Fiberglass continuous strand mat(CSM)/poly(urethane-isocyanurate) composites were formed by SRIM process, treated under different conditions and then characterized based on dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) ,transmission electron microscopy (TEM) and the mechanical property tests. The results show that the mechanical properties of the composites could be increased with improving the degree of microphase separation. At a given temperature (120°C), the degree of microphase separation is the highest for 4h and decreases gradually with prolonging treatment time. For a given time (4h), the well microphase-separated morphology is obtained and the degree of microphase mixing is increased at 120°C and 140°C treatments, respectively. The degree of microphase separation of the composites decreases with enhancing the temperature to 140°C.

Processing of Biodegradable Polymer Composite Using Soy Protein-Based Resin and Nanoclay

2016 ◽  
Author(s):  
Mohammad K. Hossain ◽  
Samira N. Shaily ◽  
Hadiya J. Harrigan ◽  
Terrie Mickens
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Soy Protein ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

A completely biodegradable composite was fabricated from an herbal polymer, soy protein concentrate (SPC) resin. Soy protein was modified by adding 30 wt% of glycerol and 5 wt% of poly vinyl alcohol (PVA) to enhance its mechanical as well as thermal property. 3%, 5%, 10%, and 20% nanoclay (NC) were infused into the system. To evaluate its mechanical properties, crystallinity, thermal properties, bonding interaction, and morphological evaluation, tensile, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) tests, and optical microscopy (OM) and scanning electron microscopy (SEM) evaluation were performed. Tensile tests showed that the addition of nanoclay improved the mechanical properties of the modified resin. Soy protein is hydrophilic due to the presence of amino acids that contain various polar groups such as amine, carboxyl, and hydroxyl. As a result, polar nanoclay particles that are exfoliated can be evenly dispersed in the SPC resin. From experimental results, it is clear that adding of nanoclay with SPC resin significantly increased the stiffness of the SPC resin. A combination of 5% clay, 30% glycerol, and 5% PVA with the modified SPC resulted in the maximum stress of 18 MPa and Young modulus of 958 MPa. The modified SPC showed a reduced failure strain as well. X-ray diffraction curves showed an improvement of crystallinity of the prepared resin with increasing amount of nanoclay. Interaction among soy, glycerol, PVA, and nanoclay was clearly demonstrated from the FTIR analysis. Optical microscopy (OM) and scanning electron microscopy (SEM) micrographs revealed rougher surface in the nanoclay infused SPC samples compared to that of the neat one. SEM evaluation revealed rougher fracture surface in the NC infused samples.

scholarly journals Effect of a Trace Addition of Sn on the Aging Behavior of Al–Mg–Si Alloy with a Different Mg/Si Ratio

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 913 ◽  
Author(s):  
Lehang Ma ◽  
Jianguo Tang ◽  
Wenbin Tu ◽  
Lingying Ye ◽  
Haichun Jiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Room Temperature ◽  
Number Density ◽  
Precipitation Behavior ◽  
Aging Behavior ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Positive Effect ◽  
Room Temperature Tensile Test

In this paper, the effect of trace Sn on the precipitation behavior and mechanical properties of Al–Mg–Si alloys with different Mg/Si ratios aged at 180 °C was investigated using hardness measurements, a room-temperature tensile test, transmission electron microscopy and differential scanning calorimetry. The results shown that Sn reduces the precipitation activation energy, increases the number density of β″ precipitates, and then increased the aging hardenability and mechanical properties of the Al–Mg–Si alloy. However, the positive effect of Sn on the mechanical properties of the Al–Mg–Si alloy drops with the decrease of the Mg/Si ratio of the alloy.

Electrical and mechanical properties enhancing of PMMA and PA6 by functionalized MWCNTs addition

MRS Advances ◽  
2018 ◽  
Vol 3 (62) ◽  
pp. 3715-3721 ◽  
Author(s):  
José J. Contreras-Navarrete ◽  
Jael M. Ambriz-Torres ◽  
Carmen J. Gutiérrez-García ◽  
Francisco G. Granados-Martínez ◽  
Diana L. García-Ruiz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Raman Spectroscopy ◽  
Functional Groups ◽  
Strong Interaction ◽  
Sem Images ◽  
Polymeric Matrices ◽  
Casting Solution ◽  
Functionalized Mwcnts

ABSTRACTPA6 and PMMA polymers with different MWCNTs addition (5, 7 and 9 wt %) were synthetized through casting solution, resulting in improvement properties in contrast to pristine polymers. SEM images showed the MWCNTs embedded into polymeric matrices. D, G and G´ bands of MWCNTs were confirmed by Raman spectroscopy and functional groups observed in both nanocomposites by FTIR demonstrated a strong interaction. A significant increasing in electrical conductivity and microhardness was observed in all the nanocomposites. Major microhardness values were obtained in MWCNTs/PA6 (50 HV) however the MWCNTs/PMMA nanocomposites showed the highest electrical conductivity value (6.4×10-4 S/cm).

Mechanical properties of jute fiber–reinforced UP/PU hybrid network composites

2019 ◽  
Vol 27 (9) ◽  
pp. 546-556 ◽  
Author(s):  
Richa Singh ◽  
B Singh ◽  
Hina Tarannum
Keyword(s):  
Mechanical Properties ◽  
Unsaturated Polyester ◽  
Fiber Surface ◽  
Mechanical Analysis ◽  
Hybrid Networks ◽  
Hybrid Network ◽  
Matrix Composites ◽  
Scanning Calorimetry ◽  
Jute Fibers ◽  
Polyester Matrix

Hybrid networks (unsaturated polyester–polyurethane (UP/PU)) of UP resin and PU prepolymer were synthesized and characterized for their phase miscibility with the help of Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis (DMA), and atomic force microscopy. The existence of hydrogen bonded –NH groups, broadened glass transition region, and reduced phase domains evidenced the formation of intermixed phase when compared with the parent UP. The optimum mechanical properties of UP/PU hybrid networks were observed at ∼5 wt% PU content. The composites made from treated jute fibers and UP/PU hybrid networks were evaluated for their physico-mechanical properties. DMA curves showed that UP/PU matrix composites had ∼20% higher storage modulus and ∼17% lower tan δ than the polyester matrix composites. The tensile and flexural strengths of these composites were increased by ∼13% and ∼40%, respectively. During accelerated aging, the UP/PU matrix composites retained ∼15% more tensile strength than the polyester matrix composites. Fractographic evidence, such as resin adherence onto the pullout fiber surface, fiber breakage, and adequate adhesion between the jute fibers and the resin, supported the superior properties of UP/PU matrix composites to polyester matrix composites.

Step-Scan DSC Study on the Melting Behavior of Polypropylene/Attapulgite Nanocomposites

2011 ◽  
Vol 284-286 ◽  
pp. 763-768
Author(s):  
Li Li Sun ◽  
Kun Hu ◽  
Lin Chen ◽  
Kang Zheng ◽  
Xing You Tian
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Melting Behavior ◽  
Secondary Crystallization ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Twin Screw ◽  
Multiple Melting ◽  
Scanning Electron

Attapulgite(AT) was modified by grafting with butyl acrylate(BA) via polymerizations initiated by Gamma radiation. The polypropylene(PP)/AT nanocomposites were synthesized via melting extrude in a twin-screw extruder. The thermogravimetry(TG) and scanning electron microscopy (SEM) were used to assess the graft ratio of the hybrid materials and the dispersion of AT, respectively. Step-scan differential scanning calorimetry(SSDSC) was used to study the influence of AT on the crystallization and subsequent melting behavior. The results indicated that PP and PP/AT nanocomposites underwent multiple melting and secondary crystallization processes during heating. The melting behaviours of PP and PP/AT nanocomposites varied with the variation of crystallization temperature and AT content.

Processibility and Thermo-Mechanical Properties of Epoxy as Reactive Plasticizer of Polyetherimide

2017 ◽  
Vol 264 ◽  
pp. 228-231
Author(s):  
Nasuha Marzuki ◽  
Muhamad Amirul Ashraf Mohd Alias ◽  
Arjulizan Rusli ◽  
Zulkifli Ahmad
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Early Stage ◽  
Scanning Calorimetry ◽  
Two Phase ◽  
Dispersed Particles ◽  
Epoxy Blends ◽  
Scanning Electron

A relatively new way to improve processibility thermoplastics is via the use of crosslinkable monomers which can act as reactive plasticizers and reduce the viscosity in the early stage of processing. The monomers can polymerize and phase separate during final stage of processing thus recovering the original thermoplastics properties. In this work, the applicability of epoxy as reactive plasticizer for polyetherimide (PEI) was investigated. The properties of PEI/epoxy blends without and with curative were studied in order to determine the effect of the monomer on the processibility of the PEI and the thermo-mechanical properties of cured blends. Differential Scanning Calorimetry on blends without curative indicated single glass transition temperature (Tg) at high PEI content suggesting miscibility of the system and plasticization of PEI in the presence of epoxy while cured blends indicated two Tg due to phase separation. Scanning electron microscopy of the cured blends indicated two phase morphology with PEI dispersed particles size increased in continuous epoxy matrix with increasing PEI (up to 30wt% PEI). In blends with 40wt% PEI and more, phase inverted morphology was observed where increasing PEI content caused reduction of epoxy particle size in continuous PEI matrix.

Crystallization, Morphology and Mechanical Properties of PLA/PBAT/CaCO3 Composites

2012 ◽  
Vol 602-604 ◽  
pp. 768-771 ◽  
Author(s):  
Nan Shi ◽  
Jun Cai ◽  
Qiang Dou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Crystallization Behavior ◽  
Mechanical Test ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Crystallization Morphology ◽  
Morphology And Mechanical Properties ◽  
Scanning Electron

The melting, crystallization behavior, morphology and mechanical properties of poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT)/calcium carbonate (CaCO3) composites were investigated by means of differential scanning calorimetry (DSC), scanning electron microscopy(SEM), and mechanical test. It is shown that PBAT decreases the crystallinity, while CaCO3 increases the crystallinity of the composites. A synergistic toughening effect is obtained by the combination of CaCO3 and PBAT. The optimum mechanical properties can be achieved in case of the composite (PLA: PBAT: CaCO3=60: 20: 20).

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