scholarly journals Propionic Anhydride Modification of Cellulosic Kenaf Fibre Enhancement with Bionanocarbon in Nanobiocomposites

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4248
Author(s):  
Samsul Rizal ◽  
E. M. Mistar ◽  
A. A. Oyekanmi ◽  
Abdul Khalil H.P.S. ◽  
Tata Alfatah ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Mechanical Performance ◽  
Thermal Analyses ◽  
Vinyl Esters ◽  
Cellulosic Fibre ◽  
Good Thermal Stability ◽  
Degradation Temperature ◽  
Kenaf Fibre ◽  
Propionic Anhydride ◽  
Fibre Matrix

The use of chemical modification of cellulosic fibre is applied in order to increase the hydrophobicity, hence improving the compatibility between the fibre and matrix bonding. In this study, the effect of propionic anhydride modification of kenaf fibre was investigated to determine the role of bionanocarbon from oil palm shell agricultural wastes in the improvement of the functional properties of bionanocomposites. The vinyl esters reinforced with unmodified and propionic anhydride modified kenaf fibres bio nanocomposites were prepared using 0, 1, 3, 5 wt% of bio-nanocarbon. Characterisation of the fabricated bionanocomposite was carried out using FESEM, TEM, FT-IR and TGA to investigate the morphological analysis, surface properties, functional and thermal analyses, respectively. Mechanical performance of bionanocomposites was evaluated according to standard methods. The chemical modification of cellulosic fibre with the incorporation of bionanocarbon in the matrix exhibited high enhancement of the tensile, flexural, and impact strengths, for approximately 63.91%, 49.61% and 54.82%, respectively. The morphological, structural and functional analyses revealed that better compatibility of the modified fibre–matrix interaction was achieved at 3% bionanocarbon loading, which indicated improved properties of the bionanocomposite. The nanocomposites exhibited high degradation temperature which signified good thermal stability properties. The improved properties of the bionanocomposite were attributed to the effect of the surface modification and bionanocarbon enhancement of the fibre–matrix networks.

Synthesis and characterization of oligo-4-[(pyridin-3-ylimino)methyl]phenol

2007 ◽  
Vol 61 (3) ◽  
Author(s):  
İ. Kaya ◽  
S. Çulhaoğlu ◽  
D. Şenol
Keyword(s):  
Molecular Orbital ◽  
Thermal Analyses ◽  
Size Exclusion ◽  
Degradation Temperature ◽  
Highest Occupied Molecular Orbital ◽  
N2 Atmosphere ◽  
Exclusion Chromatography ◽  
N Doping ◽  
Lowest Unoccupied Molecular Orbital ◽  
Optimum Reaction

AbstractThe oxidative polycondensation of 4-[(pyridin-3-ylimino)methyl]phenol (4-PIMP) with O2, H2O2, and NaOCl was studied in an aqueous alkaline medium between 50°C and 90°C. Oligo-4-[(pyridin-3-ylimino)methyl]phenol (O-4-PIMP) prepared was characterized by 1H-NMR, 13C-NMR, FT-IR, UV-VIS, size-exclusion chromatography, and elemental and thermal analyses techniques. At the optimum reaction conditions, the yield of O-4-PIMP was 18.9%, 39.4%, and 46.8% using H2O2, O2, and NaOCl oxidant, respectively. According to the TG analysis, the initial degradation temperature of O-4-PIMP was 218°C, which was by 50°C higher than that of 4-PIMP. Thermal analyses of 4-PIMP and O-4-PIMP were carried out in N2 atmosphere at 15–1000°C. The highest occupied molecular orbital, the lowest unoccupied molecular orbital, and electrochemical energy gaps of 4-PIMP and O-4-PIMP were determined from the onset potentials for n-doping and p-doping, respectively. Also, optical band gaps of 4-PIMP and O-4-PIMP were determined according to UV-VIS measurements.

Development of novel high Tg polyimide-based composites. Part II: Mechanical characterisation

2017 ◽  
Vol 52 (2) ◽  
pp. 261-274 ◽  
Author(s):  
Spyros Tsampas ◽  
Patrik Fernberg ◽  
Roberts Joffe
Keyword(s):  
Elevated Temperature ◽  
Composite System ◽  
Mechanical Performance ◽  
Mechanical Tests ◽  
Basic Material ◽  
Mechanical Characterisation ◽  
Short Beam ◽  
Fibre Treatment ◽  
Beam Shear ◽  
Fibre Matrix

In this study, the mechanical performance assessment of a newly developed carbon fibre-reinforced polyimide composite system T650/NEXIMID® MHT-R is presented. This system was subjected to a series of mechanical tests at ambient and elevated temperature (320℃) to determine basic material properties. Moreover, an additional test was conducted, using a T650/NEXIMID® MHT-R laminate in which the fibre sizing was thermally removed prior to laminate manufacturing, to investigate the effect of fibre treatment on mechanical performance. The experimental results indicated that the T650/NEXIMID® MHT-R composites along with exceptionally high Tg (360–420℃) exhibited competitive mechanical properties to other commercially available polyimide and epoxy-based systems. At elevated temperature, the fibre-dominated properties were not affected whilst the properties defined by matrix and fibre/matrix interface were degraded by approximately 20–30%. Finally, the fibre sizing removal did not affect the tensile and compressive strength, however, the shear strength obtained from short-beam shear test was deteriorated by approximately 15%.

scholarly journals A NEW CLASS OF IONIC SOLVENTS, ELECTROLYTES AND ENGINEERING FLUIDS BASED ON 1,3-ALKYLMETHYL-1,2,3-BENZOTRIAZOLIUM SALTS

2010 ◽  
Vol 6 (2) ◽  
pp. 111-116 ◽  
Author(s):  
Ahmad Mudzakir
Keyword(s):  
Ionic Liquids ◽  
Single Crystal ◽  
Thermal Analyses ◽  
Spectroscopic Studies ◽  
Electrochemical Analysis ◽  
Electrochemical Characteristics ◽  
Melting Points ◽  
X Ray ◽  
Good Thermal Stability ◽  
New Class

A new series of ionic liquids based on 1,3-alkylmethyl-1,2,3-benzotriazolium cation has been prepared. The spectroscopic, physical and electrochemical characteristics of this family of salts have been investigated with respect to potential usage as ionic solvents, electrolytes and engineering fluids. Incorporation of diverse anions including weak coordinating anion and pseudohalide with this benzotriazolium cation produces ionic liquids with advantageously low melting points and good thermal stability. Thermal analyses of these very stable salts included the determination of melting points (-65 to 164 oC) and decomposition temperatures (up to 291 oC). The electrochemical windows of representative benzotriazolium species has been investigated by cyclic voltammetry and determined to be ~ 3 V. The X-ray single crystal and spectroscopic studies revealed that weak hydrogen-bonding interactions between the benzotriazolium ring protons and the anions are present both in the solid state as well as in solution.   Keywords: ionic liquids, X-ray single crystal, thermal analysis, electrochemical analysis, benzotriazolium salt

Detection of Voids in Carbon/Epoxy Laminates and Their Influence on Mechanical Properties

2017 ◽  
Vol 25 (5) ◽  
pp. 371-380 ◽  
Author(s):  
Luca Di Landro ◽  
Aurelio Montalto ◽  
Paolo Bettini ◽  
Stefania Guerra ◽  
Fabrizio Montagnoli ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Mechanical Performance ◽  
Thermal Analyses ◽  
Void Content ◽  
Processing Conditions ◽  
Micro Computed Tomography ◽  
Sem Image ◽  
Beam Shear ◽  
Mechanical Performances ◽  
Curing Cycle

Defects, such as voids and delaminations, may significantly reduce the mechanical performance of components made of composite laminates. Distributed voids and porosity are generated during composite processing and are influenced by prepreg characteristics as well as by curing cycle parameters. On the basis of rheological and thermal analyses, as well as observations of laminates produced by different processing conditions, curing pressure appears the most influent factor affecting the void content. This work compares different methods for void analysis and quantitative evaluation (ultrasonic scan, micro-computed tomography, acid digestion, SEM image analysis) evidencing their applicative limitations. Carbon/epoxy laminates were produced in autoclave or oven by vacuum bag technique, using different processing conditions, so that void contents ranging from 0% to 7% volume were obtained. Effects of porosity over laminates mechanical performances are analysed. The results of tensile and compressive tests are discussed, considering the effect that different curing cycles have over void content as well as over fibre/resin fraction. Interlaminar strength, as measured by short beam shear tests, which is a matrix-dominated property, exhibits a reduction of failure strength up to 25% in laminates with the highest void content, compared to laminates with no porosity.

Thermal and mechanical properties of chemical modification on sugarcane bagasse mixed with polypropylene and recycle acrylonitrile butadiene rubber composite

2019 ◽  
Vol 33 (11) ◽  
pp. 1533-1554 ◽  
Author(s):  
Mustaffa Zainal ◽  
Ragunathan Santiagoo ◽  
Afizah Ayob ◽  
Azlinda Abdul Ghani ◽  
Wan Azani Mustafa ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Tensile Properties ◽  
Sugarcane Bagasse ◽  
Chemical Properties ◽  
Infrared Analysis ◽  
Butadiene Rubber ◽  
Acrylonitrile Butadiene Rubber ◽  
Degradation Temperature ◽  
Roll Mill ◽  
Rubber Composite

The goal of this research is to investigate the thermal, chemical, and tensile properties of chemical modification of sugarcane bagasse (SCB)-filled polypropylene (PP) and recycled acrylonitrile butadiene rubber (NBRr). The composites with different SCB loading (5, 15, and 30 per hundred resin) were prepared using a heated two-roll mill at temperature of 180°C.Thermal and the tensile properties of the modified SCB composite have shown improvement. The silane-treated composites have higher thermal stability compared to treated NaOH. The degradation temperature at 70% weight ( T 70%) of NaOH and silane composite increase by 6% and 15%, respectively. Meanwhile, the tensile strength and Young’s modulus for the both treatment showed an improvement of 20% and 25% for NaOH and 30% and 32% for silane compared to untreated composites, respectively. The chemical properties were investigated using Fourier transform infrared analysis. The modification SCB fiber has improved the adhesion and interfacial bonding between SCB fiber and PP/NBRr matrices.

On the Mechanical Reliability of Photo-BCB-Based Thin Film Dielectric Polymer for Electronic Packaging Applications

1999 ◽  
Vol 122 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Jang-hi Im ◽  
Edward O. Shaffer ◽  
Theodore Stokich, ◽  
Andrew Strandjord ◽  
Jack Hetzner ◽  
...  
Keyword(s):  
Thin Film ◽  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Moisture Absorption ◽  
Mechanical Performance ◽  
Adhesion Promoter ◽  
Helium Atmosphere ◽  
Thermally Induced ◽  
Good Thermal Stability ◽  
Substrate Surfaces

This work examines the mechanical performance of thin film coatings from Photosensitive-benzocyclobutene (Photo-BCB) formulations (Cyclotene2 4024, 4026 and 7200), on various substrate surfaces such as Al, Cu, Si, and SiN. The adhesion promoter used was designated AP-3000 and was based on vinyltriacetoxysilane (VTAS), which had been properly hydrolyzed and advanced. Measurement of the interfacial adhesion was performed primarily using the modified Edge Liftoff Test m-ELT. It was found that, by applying the newly developed adhesion promoter, AP-3000, the interfacial energy of Photo-BCB to Al, Cu, Si, and SiN was significantly improved, often approaching the toughness of Photo-BCB, ca. 45 J/m2. The x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) analyses of the delaminated surfaces of the Photo-BCB/Al structure revealed distinct differences in surface roughness and the chemical composition depending on whether or not adhesion promoter was used. Other parameters important for long term stability (e.g., moisture uptake and thermal stability) of Photo-BCB were also measured. The equilibrium moisture content at 84 percent RH in ambient temperature was low, 0.14 wt percent and the thermally induced weight loss at 330°C in helium atmosphere was less than 1 percent/h. The low moisture absorption and good thermal stability, together with the given mechanical toughness and adhesion, allow the Photo-BCB to be widely usable for various microelectronic packaging applications, for up to 40 μm thick build in the case of silicon substrate. [S1043-7398(00)00701-5]

scholarly journals Microstructure and Mechanical Properties of Composite Resins Subjected to Accelerated Artificial Aging

2013 ◽  
Vol 24 (6) ◽  
pp. 599-604 ◽  
Author(s):  
Andrea Candido dos Reis ◽  
Denise Tornavoi de Castro ◽  
Marco Antonio Schiavon ◽  
Leandro Jardel da Silva ◽  
Jose Augusto Marcondes Agnelli
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Artificial Aging ◽  
Thermal Analyses ◽  
Surface Hardness ◽  
Composite Resins ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Microstructure And Mechanical Properties ◽  
Before And After

The aim of this study was to investigate the influence of accelerated artificial aging (AAA) on the microstructure and mechanical properties of the Filtek Z250, Filtek Supreme, 4 Seasons, Herculite, P60, Tetric Ceram, Charisma and Filtek Z100. composite resins. The composites were characterized by Fourier-transform Infrared spectroscopy (FTIR) and thermal analyses (Differential Scanning Calorimetry - DSC and Thermogravimetry - TG). The microstructure of the materials was examined by scanning electron microscopy. Surface hardness and compressive strength data of the resins were recorded and the mean values were analyzed statistically by ANOVA and Tukey's test (α=0.05). The results showed significant differences among the commercial brands for surface hardness (F=86.74, p<0.0001) and compressive strength (F=40.31, p<0.0001), but AAA did not affect the properties (surface hardness: F=0.39, p=0.53; compressive strength: F=2.82, p=0.09) of any of the composite resins. FTIR, DSC and TG analyses showed that resin polymerization was complete, and there were no differences between the spectra and thermal curve profiles of the materials obtained before and after AAA. TG confirmed the absence of volatile compounds and evidenced good thermal stability up to 200 °C, and similar amounts of residues were found in all resins evaluated before and after AAA. The AAA treatment did not significantly affect resin surface. Therefore, regardless of the resin brand, AAA did not influence the microstructure or the mechanical properties.

CHARACTERIZATION OF RUBBER TOUGHENED EPOXY REINFORCED HYBRID KENAF/CARBON FIBER VIA WATER ABSORPTION AND THERMAL DEGRADATION

2015 ◽  
Vol 76 (3) ◽  
Author(s):  
Mimi Azlina Abu Bakar ◽  
Sahrim Ahmad ◽  
Salmiah Kasolang ◽  
Mohamad Ali Ahmad ◽  
Nik Roselina Nik Roseley ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Carbon Fiber ◽  
Thermal Degradation ◽  
Water Absorption ◽  
Machine Model ◽  
Degradation Temperature ◽  
Kenaf Fibre ◽  
Rubber Toughened ◽  
Treated Fiber

Toughened epoxies reinforced by hybrid of kenaf/carbon fiber, untreated and treated, with the addition of liquid epoxidized natural rubber (LENR), were tested for their water absorption and thermal degradation. Water absorption testing was conducted based on ASTM D1037 to study the effects of kenaf fibre and carbon fibre on water uptake property. In the thermal analysis, the thermal degradation of the specimen was investigated towards heat. The test used a termogravimetric analysis machine, model Mettler Toledo-TGA, at temperature range of 50 OC to 350 OC with an increment of 10 OC/min where the results showed the decreasing of degradation temperature when the treated fiber was used. The results also showed that the percentage of water absorptions for composites with the addition of LENR were lower compared to those of composites without LENR. 

Microscopy Observation on Nanocellulose from Kenaf Fibre

2012 ◽  
Vol 488-489 ◽  
pp. 72-75 ◽  
Author(s):  
Siti Norasmah Surip ◽  
W.N.R. Wan Jaafar ◽  
N.N. Azmi ◽  
U.M.K. Anwar
Keyword(s):  
Binding Site ◽  
Surface Area ◽  
Hibiscus Cannabinus ◽  
High Yield ◽  
Microscopy Observation ◽  
Mechanical Method ◽  
Fibre Size ◽  
Kenaf Fibre ◽  
A New Technique ◽  
Fibre Matrix

Conventional fibre size has large surface area for binding site while nanocellulose posses higher surface area thus making more available binding site for fibre-matrix interaction. Kenaf has poor surface properties before treated. Treatment was applied to overcome this problem with alkali followed by acidic treatment. The nanocellulose has been produced from kenaf core (hibiscus cannabinus) by chemi-mechanical method. The fibre was treated with alkali followed by acidic treatment (HCl). Treated fibres were mechanically process by using pulverisette & cryocrushing to reduce the fibre size. The nanocellulose fibres were observed under Scanning Electron Microscope (SEM). The result convinced that chemi-mechanical method is a new technique for producing high yield kenaf nanocellulose.

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