scholarly journals Bio-Composites Reinforced with Strontium Titanate Nanoparticles: Mechanical Behavior and Degradability

2019 ◽  
Vol 3 (1) ◽  
pp. 7 ◽  
Author(s):  
Amarilis Declet-Vega ◽  
Nelson Sepúlveda-Ramos ◽  
Sandra Crespo-Montoya ◽  
Oscar Marcelo Suárez
Keyword(s):  
Tensile Strength ◽  
Strontium Titanate ◽  
Cost Effective ◽  
Tensile Tests ◽  
Cellulose Content ◽  
Acidic Solutions ◽  
Degradation Temperature ◽  
Elastic Coefficients ◽  
Thermal Degradation Temperature

Bio-polymer-based composites are appealing cost-effective and environmentally friendly materials for electronic applications. This project relates to bio-composites made of chitosan and cellulose and reinforced with strontium titanate nanoparticles. Upon their fabrication, relevant parameters studied were the acetic acid concentration, the cellulose content, and the amount of strontium titanate nanoparticles. The specimens were characterized using thermogravimetric and degradation analyses, as well as via creep and tensile tests. The results revealed how higher cellulose levels lowered the ultimate tensile strength and the degradation temperature of the bio-composites. Moreover, when nanoparticles are present, higher cellulose levels contributed to their tensile strength. Additionally, more acidic solutions became detrimental to the mechanical properties and the thermal degradation temperature of the composites. Furthermore, the creep studies allowed determining elastic coefficients and viscous coefficients using the Burgers’ model. Those creep results suggest that higher amounts of SrTiO3 (STO) nanoparticles raised the composites creep strain rate. As a whole, the study provides a baseline characterization of these novel bio-composites when subject to aggressive environments.

Synthesis and characterization of methyltetrahydrophthalic anhydride esterified corn starch by wet method

2021 ◽  
Vol 11 (7) ◽  
pp. 1223-1230
Author(s):  
Ting Luo ◽  
Chengdong Yang ◽  
Kang Zhang ◽  
Yi Lin ◽  
Fei Cheng ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Corn Starch ◽  
Light Transmittance ◽  
Synthesis And Characterization ◽  
Maximum Elongation ◽  
Elongation At Break ◽  
Degradation Temperature ◽  
Methyltetrahydrophthalic Anhydride ◽  
Thermal Degradation Temperature

The main purpose of this paper is to synthesize a novel esterified starch with an alicyclic structure. Herein, methyltetrahydrophthalic anhydride (MeTHPA), an alicyclic anhydride, was used to synthesize esterified corn starch (CS) with different degrees of substitution (DS) by a wet method. Compared with CS, the crystallinity and thermal degradation temperature of MeTHPA esterified CS (MeCS) decreased, while the hydrophobicity and light transmittance of MeCS films increased. The esterification modification significantly improved the toughness of the starch film. Between CS and MeCS films, the 15% Me/CS film shows a maximum elongation at break of 24.2% and a tensile strength of 8.0 MPa. Furthermore, 15% Me/CS was blended with CS as a sizing agent for polyester/cotton blended yarns and showed significantly increased adhesion to the blended yarns. Hence, the CS blended MeCS has a potential application in wrap sizing.

Polymer Pendant Crown Thioethers for Removal of Mercury from Acidic Waste Streams-Characterization and Extraction Performance

2002 ◽  
Vol 757 ◽  
Author(s):  
Theodore F. Baumann ◽  
Glenn A. Fox ◽  
Art J. Nelson ◽  
Joy C. Andrews ◽  
Darrell B. Bishop ◽  
...  
Keyword(s):  
Binding Sites ◽  
Cost Effective ◽  
Loading Capacity ◽  
High Concentration ◽  
Waste Streams ◽  
Acidic Solutions ◽  
Crown Thioethers ◽  
Ph Range ◽  
Competing Ions

ABSTRACTThe removal and immobilization of mercury(II) ions from industrial waste streams is a difficult and expensive problem requiring a robust extractant that is resistant to corrosive conditions. We have now developed an acid-resistant thiacrown polymer that has potential utility as a selective and cost-effective Hg2+ extractant. A new crown thioether, 2-hydroxymethyl-1,4,8,11,14-pentathiacycloheptadecane ([17] aneS5-OH), was synthesized through reaction of 2,3-dimercapto-1-propanol with 4,7,10-trithiatridecane-1,13-di-p-toluenesulfonate; then treated with thionyl chloride to form 2-chloromethyl-1,4,8,11,14-pentathiacycloheptadecane ([17] aneS5-Cl); followed by conversion to 2-(N-methyl)aminomethyl-1,4,8,11,14-pentathiacycloheptadecane ([17] aneS5-NHMe), through reaction with methylamine. The synthesis of the 4-vinylbenzyl-substituted thiacrown was readily accomplished by treating with 4-vinylbenzyl chloride. Co-polymerization of the 4-vinylbenzyl-substituted thiacrown with DVB (80% divinylbenzene) using AIBN as the radical initiator generated the highly cross-linked crown thioether polymer. The polymer based material was tested for Hg(II) extraction activity from acidic solutions. The material was found to extract 95+% of the Hg in a pH range of around 1.5 to over 6.0, with contact times of less than 30 min and in the presence of high concentration of competing ions such as Pb, Cd, Al, and Fe. The spent polymer could also be stripped of the Hg2+ and reused without sufficient loss of loading capacity. Characterization of the binding sites by XPS and XAS show only some of the S atoms in the thiacrown participate in the binding of Hg. Our results indicate this polymer has the potential to treat highly acidic wastes efficiently. This thiacrown polymer is far more effective in extracting Hg2+ from aqueous solution than previously reported Hg2+ extrac-tants, not only being very fast and efficient and selective, but also independent of pH.

Synthesis, Characterization and Properties of Polyesteramides Based on ε-Caprolactone and 6-Aminocaproic Acid

2011 ◽  
Vol 287-290 ◽  
pp. 1538-1547 ◽  
Author(s):  
Yi He ◽  
You Ru Du ◽  
Xiao Bo Liu
Keyword(s):  
Tensile Strength ◽  
Tensile Testing ◽  
Aminocaproic Acid ◽  
Amide Bond ◽  
Ester Bond ◽  
Degradation Temperature ◽  
Melt Polycondensation ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Thermal Degradation Temperature

Biodegradable aliphatic polyesteramides were synthesized from ε-caprolactone and 6-aminocaproic acid by melt-polycondensation method. FTIR, 1H-NMR, DSC, WAXD, TG, and tensile testing were used to characterize the polyesteramides. With the increase in 6-aminocaproic acid content, the melting temperature, thermal degradation temperature and tensile strength at break increased accordingly. The ester bond decomposes at lower temperature, and then the amide bond decomposes at higher temperature.

scholarly journals Effect of addition of different reinforcements on the microstructure and mechanical characterization of the Al-Flyash composites

2021 ◽  
Vol 15 (56) ◽  
pp. 217-228
Author(s):  
Milind K. Wasekar ◽  
Mohan P. Khond
Keyword(s):  
Tensile Strength ◽  
Hybrid Composites ◽  
Tensile Tests ◽  
Stir Casting ◽  
Interface Bonding ◽  
Casting Technique ◽  
Testing Procedures ◽  
The Matrix ◽  
Aluminum 6061 Alloy

The aim of this work is to investigate the influence of the addition of silicon carbide and molybdenum disulfide on the microstructure and the tensile strength of the Al-Flyash hybrid composites prepared using the stir casting technique. The composite with aluminum 6061 alloy as the matrix and flyash as the reinforcement, with different weight fractions, is investigated to study its microstructure and the tensile strength. The same has been compared with the hybrid composites with Aluminum-Flyash/SiC and Aluminum-Flyash/MoS2 for different weight fractions of the reinforcements. The tensile tests were conducted as per ASTM standard testing procedures at room temperature. From the results it is identified that tensile strength of the Al6061-Flyash composite is lesser than the Al6061-Flyash/SiC and Al6061-Flyash/MoS2 hybrid composites. It is also observed that increment in the composition of the SiC and MoS2 causes the increment in the tensile strength of the hybrid composite. This increment in the tensile strength is due to good interface bonding and uniform distribution of the reinforcements in the composite.

An Alternative Approach for FRCM Matrix Tensile Strength Evaluation

2019 ◽  
Vol 817 ◽  
pp. 365-370 ◽  
Author(s):  
Alessandro Bellini ◽  
Marco Bovo ◽  
Andrea Incerti ◽  
Claudio Mazzotti
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Mechanical Characterization ◽  
Experimental Tests ◽  
Tensile Tests ◽  
Test Methods ◽  
Test Method ◽  
The Matrix ◽  
Flexural Tests

Structural retrofitting with composite materials proved to be an effective technique for rehabilitation of degraded or damaged masonry and concrete buildings. Nowadays, Fiber Reinforced Cementitious Matrix (FRCM) composites are widely used as externally bonded strengthening systems thanks to their high performance, low weight and easiness of installation. Several experimental tests and numerical studies are currently available concerning the tensile and bond behavior of FRCM systems, but a debated and still open issue concerns the methods for the mechanical characterization of the mortar used as matrix within the strengthening system. The present paper analyses and compares different test methods for determining the matrix tensile strength. Pure tensile and flexural tests have been carried out on different mortar matrix samples. In order to evaluate which is the most suitable value to be considered for a correct interpretation and modeling of the composite system, the experimental results obtained through flexural tests on standard mortar specimens have been compared with the outcomes obtained from direct tensile tests on FRCM coupons. The present study represents only a first step for the definition of the most appropriate test method for the mechanical characterization of the matrix used within FRCM strengthening systems.

Synthesis and Characterization of Microcellular Injection Molded Polyolefin/Polycaprolactone Composites

2021 ◽  
Vol 1041 ◽  
pp. 11-15
Author(s):  
Shyh Shin Hwang ◽  
Shia Chung Chen ◽  
Chiu Lan Yang
Keyword(s):  
Tensile Strength ◽  
Thermal Properties ◽  
Cell Size ◽  
Cell Density ◽  
Synthesis And Characterization ◽  
Degradation Temperature ◽  
The Matrix ◽  
Filler Dispersion ◽  
Injection Molded

This study investigated the effect of polycaprolactone (PCL) loading (0.5, 1, and 3 wt%) on the morphology, tensile strength, and thermal properties of microcellular injection molded PP/PCL and PPgMA/PCL composites. We used the filler, PCL, that is micro-material in size. Results showed that 0.5 wt% loading of PCL on foamed PP has the largest tensile strength. However, tensile strength was almost similar to that of PPgMA composites. Tensile strength depends on the filler dispersion in the matrix and cell size present on the foamed composites. Good dispersion resulted in good tensile strength. The elongation decreased on PP but increased on PPgMA composites. The highest degradation temperature for PP/PCL and PPgMA/PCL was noted for 3.0 wt% PCL loading and neat PPgMA respectively. Cell size decreased and cell density increased with the addition of PCL into the PP and PPgMA matrix.

Characterization of antibacterial nanocomposites of polyethylene terephthalate filled with nanosilver-doped carbon black

2020 ◽  
pp. 096739112093530
Author(s):  
Manuel Reyes De Guzman ◽  
Yi-Hua Wen ◽  
Juan Du ◽  
Ling Yuan ◽  
Chin-San Wu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Carbon Black ◽  
Polyethylene Terephthalate ◽  
Antibacterial Properties ◽  
Crystallization Rate ◽  
Tensile Tests ◽  
Industrial Applications ◽  
X Ray Diffraction ◽  
X Ray

A new filler for polyethylene terephthalate (PET) was synthesized by doping carbon black (CB) with nanosilver. Images taken from energy-dispersive X-ray spectrometry and X-ray diffraction validated the synthesis of the filler (nanosilver-doped CB (CB-Ag)). We evaluated the effect of CB-Ag on the mechanical, thermal, and antibacterial properties of the nanocomposites (CB-Ag/PET). Thermogravimetric analyses, morphology, and tensile tests indicated that thermodegradation, crystallization rate, and tensile strength were all improved as a result of filling PET with CB-Ag. Excellent antibacterial properties were imparted to PET nanocomposites, which would be useful for a wide array of industrial applications.

scholarly journals Low Temperature Dissolution of Yeast Chitin-Glucan Complex and Characterization of the Regenerated Polymer

2020 ◽  
Vol 7 (1) ◽  
pp. 28
Author(s):  
Diana Araújo ◽  
Vítor D. Alves ◽  
Ana C. Marques ◽  
Elvira Fortunato ◽  
Maria A. M. Reis ◽  
...  
Keyword(s):  
Cell Walls ◽  
Crystallinity Index ◽  
Degradation Temperature ◽  
Alkali Solutions ◽  
Solvent Systems ◽  
Green Procedure ◽  
First Time ◽  
Komagataella Pastoris ◽  
Thermal Degradation Temperature

Chitin-glucan complex (CGC) is a copolymer composed of chitin and glucan moieties extracted from the cell-walls of several yeasts and fungi. Despite its proven valuable properties, that include antibacterial, antioxidant and anticancer activity, the utilization of CGC in many applications is hindered by its insolubility in water and most solvents. In this study, NaOH/urea solvent systems were used for the first time for solubilization of CGC extracted from the yeast Komagataella pastoris. Different NaOH/urea ratios (6:8, 8:4 and 11:4 (w/w), respectively) were used to obtain aqueous solutions using a freeze/thaw procedure. There was an overall solubilization of 63–68%, with the highest solubilization rate obtained for the highest tested urea concentration (8 wt%). The regenerated polymer, obtained by dialysis of the alkali solutions followed by lyophilization, formed porous macrostructures characterized by a chemical composition similar to that of the starting co-polymer, although the acetylation degree decreased from 61.3% to 33.9–50.6%, indicating that chitin was converted into chitosan, yielding chitosan-glucan complex (ChGC). Consistent with this, there was a reduction of the crystallinity index and thermal degradation temperature. Given these results, this study reports a simple and green procedure to solubilize CGC and obtain aqueous ChGC solutions that can be processed as novel biomaterials.

Preparation and characterization of acetic acid lignin-based epoxy blends

BioResources ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. 2860-2870
Author(s):  
Pan Feng ◽  
Fangeng Chen
Keyword(s):  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Aqueous Sodium Hydroxide ◽  
Diglycidyl Ether ◽  
Degradation Temperature ◽  
Acetic Acid Lignin ◽  
Epoxy Blends ◽  
Thermal Degradation Temperature ◽  
Adhesive Shear Strength

Lignin-based epoxy resin (LER) was prepared from phenolated lignin (PL) and epichlorohydrin (ECH) in the presence of sodium hydroxide. The eucalyptus acetic acid lignin (AAL) was first reacted with phenol in the presence of sulfuric acid to obtain PL. Then, PL was reacted with ECH in aqueous sodium hydroxide to obtain LER. LER was mixed with diglycidyl ether of bisphenol A (E-44) and then cured with triethylenetetramine (TETA). The initial thermal degradation temperature (Td) of the cured epoxy blends decreased with the increase in LER content. The residue ratio at 500 °C of the cured epoxy blends (R500), however, increased with the LER content. The maximum adhesive shear strength of the cured epoxy blends was obtained at 20 wt% of LER. The water absorption of epoxy blends increased with increasing the content of LER. SEM photos showed that increasing the content of LER increased inhomogeneity and porosity of epoxy blends.

Characterization of Hydrogels Based on PVP/Sodium Alginate Containing Pseudoboehmites Nanoparticles Treated with Octadecylamine for Pharmaco Applications

2012 ◽  
Vol 86 ◽  
pp. 92-101
Author(s):  
Leila Figueiredo de Miranda ◽  
Antonio Hortêncio Munhoz ◽  
Mauro Cesar Terence ◽  
Talita Rocha Rigolin ◽  
Laura Engel
Keyword(s):  
Tensile Strength ◽  
Drug Release ◽  
Ionizing Radiation ◽  
Sodium Alginate ◽  
Sol Gel ◽  
Tensile Tests ◽  
Degree Of Hydration ◽  
Dta And Tg ◽  
High Degree

Abstract. Hydrogels based on poly (N-vinyl-2-pyrrolidone) (PVP) obtained by ionizing radiation are sterile, biocompatible can be used as topics dressings. Due to the high degree of hydration of the gel, it has a low mechanical strength, which is one of the biggest problems in its application. The objective of this work was to study the properties of the hydrogel based on PVP / sodium alginate containing pseudoboehmites nanoparticles treated with octadecylamine for pharmaco applications, order drug release when immobilized on a matrix of PVP/sodium alginate/pseudoboehmite. Pseudoboehmite nanoparticles were obtained by sol-gel route, from aluminum nitrate and ammonia as precursors, and subsequently were treated with octadecylamine. The hydrogels based on PVP/sodium alginate/pseudoboehmite treated were prepared by ionizing radiation with doses of 30 and 35kGy. The characterization of hydrogels obtained was made by means of thermomechanical (tensile tests, DTA and TG) and physicochemical (swelling, sol-gel fraction) tests. The results obtained showed that the hydrogel based only on PVP and sodium alginate showed highest tensile strength. The presence of pseudoboehmite in the hydrogels decreases the formation of crosslinks, while the presence of PEG in the agar and causes a decrease in Tg of the polymer matrix.

Sign in / Sign up

Export Citation Format

Share Document