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.

Effects of Sr Addition on Mechanical Properties and Microstructure of Mg-6Al Magnesium Alloy

2011 ◽  
Vol 686 ◽  
pp. 120-124
Author(s):  
Jin Ping Fan ◽  
She Bin Wang ◽  
Bing She Xu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Strengthening Mechanism ◽  
Microstructure And Mechanical Properties ◽  
Higher Temperature ◽  
Lower Temperature

The effects of Sr addition on the mechanical properties and microstructure of Mg-6Al mag- nesium alloy both at 25 °C and at 175 °C were investigated by means of OM, SEM and EDS and XRD. Upon the Sr addition of 2%, the tensile strength was increased by 7.2% to 184.4MPa at 25 °C, while it was increased by 30% to 155.4MPa at 175 °C. The strengthening mechanism of Mg-6Al-xSr at lower temperature (25 °C) was different from that at higher temperature (175°C). The results show that the addition of strontium effectively improved the microstructure and mechanical properties of magnesium alloy.

Study of the Properties of Poly-P-Phenylene-Benzimidazole-Terephthalamide Fiber Material

2011 ◽  
Vol 204-210 ◽  
pp. 919-923
Author(s):  
Ning Sun ◽  
Yin Xing Liang ◽  
Zhen Tong
Keyword(s):  
Thermal Stability ◽  
High Performance ◽  
Fiber Material ◽  
Experimental Conditions ◽  
Leading Role ◽  
Degradation Temperature ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Hydrolytic Mechanism ◽  
Heterocyclic Polymer

The properties of the fiber material, which prepared from the high-performance heterocyclic polymer poly-p-phenylene-benzimidazole-terephthalamide (PBIA), were investigated. Poly-m-phenylene isophthalamide (PMIA) and poly-p-phenylene terephthalamide (PPTA) fibers were also studied, for comparison, under the same experimental conditions. Thermogravimetry(TG) and thermogravimetry coupled to Fourier transform infrared spectroscopy(TG-FTIR) were used to study the properties of these fibers. The results show that PBIA fiber has better tensile properties, thermal stability than that of PMIA and PPTA fibers. The onset degradation temperature of PBIA is the highest, namely 421°C in nitrogen. TG-FTIR provides information on the compositions of the pyrolyzates as well as their relationship to the structures of the polyamides. Analysis of the results indicates that a hydrolytic mechanism plays a leading role at lower temperature, and a homolytic mechanism is dominant at higher temperature.

Processes of Reclaiming Rubber and Their Relative Merits

1944 ◽  
Vol 17 (2) ◽  
pp. 544-550 ◽  
Author(s):  
E. W. B. Owen
Keyword(s):  
Tensile Strength ◽  
Surface Finish ◽  
Thermal Process ◽  
Large Scale ◽  
New Products ◽  
The Other ◽  
Permanent Set ◽  
Before And After ◽  
Higher Temperature ◽  
Lower Temperature

Abstract 1. A more complete reclamation is possible by the thermal and pan process than with the alkali process, and both the former effect a saving in time. 2. The thermal process calls for a higher temperature, but the after-treatment consumes less power for grinding. The pan process makes use of a lower temperature; but the expenditure of more power for grinding before and after treatment, as well as a drying period, are entailed. 3. The new products are neutral, and softer than alkali reclaim. 4. Accelerated with BA, stocks with these new types of reclaim give poor results. On the other hand, MBT offers good prospects, both for aging and acceleration. 5. Whether refined or not, the pan reclaim produced a tensile strength 95 per cent of alkali reclaim, and the thermal reclaim 80 per cent, in MBT stocks. 6. With modified acceleration, thermal reclaim stock can be made to give improved tensile properties. 7. Laboratory abrasion resistance of both new types was superior to the standard, the losses being 92 per cent and 74 per cent for thermal and pan reclaims, respectively. 8. The permanent set was lower despite the softener in the pan reclaim. 9. Despite the lack of refining, articles formed by extrusion from stocks containing thermal and pan reclaims compared favorably with those from alkali reclaim with regard to surface finish. 10. Thermal reclaim ages extremely well. Independent workers in the field of thermal reclaim have been able to exercise a finer control of the process, and a large scale plant is in course of erection as a result of the improvements effected. Further work is proceeding, and it is hoped that a product superior in all respects to alkali reclaim will be obtained.

The thermal degradation behavior of meta- and para- hetero-amide fibers by TGA-FTIR

2013 ◽  
Vol 33 (4) ◽  
pp. 337-344 ◽  
Author(s):  
Ning Sun ◽  
Yinxing Liang ◽  
Zhaohua Xu ◽  
Heng Li ◽  
Jiang Shaohua ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Degradation Behavior ◽  
Leading Role ◽  
Degradation Temperature ◽  
Thermal Degradation Behavior ◽  
Different Temperatures ◽  
Degradation Behaviors ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Hydrolytic Mechanism

Abstract The thermal degradation behaviors of poly-p-phenylene-benzimidazole-terephthalamide (PBIA), poly-m-phenylene isophthalamide (PMIA) and poly-p-phenylene terephthalamide (PPTA) fibers are investigated by thermogravimetric analysis (TGA) coupled with Fourier transform infrared spectroscopy (TGA-FTIR). The results demonstrate that PBIA fiber exhibits better thermal- and thermo-oxidative stability than that of the other two polymers. PBIA shows the highest onset degradation temperature, both in nitrogen and air. TGA-FTIR provides information on compositions of pyrolyzates and their relationship with the structures of polyamides. Analysis of the compositions and distributions of all pyrolyzates, at different temperatures, indicates that a hydrolytic mechanism plays a leading role at lower temperature, and a homolytic mechanism is dominant at higher temperature.

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.

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.

UV Curable Organic-Inorganic Hybrid Materials

2000 ◽  
Vol 628 ◽  
Author(s):  
Guang-Way Jang ◽  
Ren-Jye Wu ◽  
Yuung-Ching Sheen ◽  
Ya-Hui Lin ◽  
Chi-Jung Chang
Keyword(s):  
Hybrid Materials ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Solution Ph ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Degradation Temperature ◽  
Sol Gel Process ◽  
The Stability ◽  
Thermal Degradation Temperature

This work successfully prepared an UV curable organic-inorganic hybrid material consisting of organic modified colloidal silica. Applications of UV curable organic-inorganic hybrid materials include abrasion resistant coatings, photo-patternable thin films and waveguides. Colloidal silica containing reactive functional groups were also prepared by reacting organic silane and tetraethyl orthosilicate (TEOS) using sol-gel process. In addition, the efficiency of grafting organic moiety onto silica nanoparticles was investigated by applying TGA and FTIR techniques. Experimental results indicated a strong interdependence between surface modification efficiency and solution pH. Acrylate-SiO2 hybrid formation could result in a shifting of thermal degradation temperature of organic component from about 200°C to near 400°C. In addition, the stability of organic modified colloidal silica in UV curable formula and the physical properties of resulting coatings were discussed. Furthermore, the morphology of organic modified colloidal silica was investigated by performing TEM and SEM studies‥

scholarly journals Sprouting of Sorghum (Sorghum bicolor [L.] Moench): Effect of Drying Treatment on Protein and Starch Features

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 407 ◽  
Author(s):  
Mia Marchini ◽  
Alessandra Marti ◽  
Claudia Folli ◽  
Barbara Prandi ◽  
Tommaso Ganino ◽  
...  
Keyword(s):  
Food Production ◽  
Cost Effective ◽  
High Exposure ◽  
Effective Technology ◽  
Drying Treatment ◽  
Higher Temperature ◽  
Lower Temperature ◽  
The One ◽  
Drying Conditions ◽  
Sorghum Bicolor L

The nutritional and physicochemical properties of sorghum proteins and starch make the use of this cereal for food production challenging. Sprouting is a cost-effective technology to improve the nutritional and functional profile of grains. Two drying treatments were used after sorghum sprouting to investigate whether the drying phase could improve the protein and starch functionalities. Results showed that the drying treatment at lower temperature/longer time (40 °C for 12 h) extended the enzymatic activity that started during sprouting compared to the one performed at higher temperature/shorter time (50 °C for 6 h). An increased protein hydrolysis and water- and oil-holding capacity were found in the flour obtained by the former treatment. Higher protein matrix hydrolysis caused high exposure of starch to enzymes, thus increasing its digestibility, while worsening the technological functionality. Overall, modulating drying conditions could represent a further way, in addition to sprouting, to improve sorghum flour’s nutritional profile.

scholarly journals Synthesis and Characterization of N-Substituted Polyether-Block-Amide Copolymers

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 773
Author(s):  
Jyun-Yan Ye ◽  
Kuo-Fu Peng ◽  
Yu-Ning Zhang ◽  
Szu-Yuan Huang ◽  
Mong Liang
Keyword(s):  
Titanium Isopropoxide ◽  
Decomposition Temperature ◽  
Phenyl Isocyanate ◽  
Cross Linking ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Degradation Temperature ◽  
Melt Polycondensation ◽  
Structural Regularity

A series of N-substituted polyether-block-amide (PEBA-X%) copolymers were prepared by melt polycondensation of nylon-6 prepolymer and polytetramethylene ether glycol at an elevated temperature using titanium isopropoxide as a catalyst. The structure, thermal properties, and crystallinity of PEBA-X% were investigated using nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, wide angle X-ray diffraction, and thermogravimetric analysis. In general, the crystallinity, melting point, and thermal degradation temperature of PEBA-X% decreased as the incorporation of N-methyl functionalized groups increased, owing to the disruption caused to the structural regularity of the copolymer. However, in N-acetyl functionalized analogues, the crystallinity first dropped and then increased because of a new γ form arrangement that developed in the microstructure. After the cross-linking reaction of the N-methyl-substituted derivative, which has electron-donating characteristics, with poly(4,4′-methylenebis(phenyl isocyanate), the decomposition temperature of the resulting polymer significantly increased, whereas no such improvements could be observed in the case of the electro-withdrawing N-acetyl-substituted derivative, because of the incompleteness of its cross-linking reaction.

Mechanical properties of low-density paper

2020 ◽  
Vol 35 (1) ◽  
pp. 61-70
Author(s):  
Na Young Park ◽  
Young Chan Ko ◽  
Lili Melani ◽  
Hyoung Jin Kim
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Structural Change ◽  
Tensile Testing ◽  
Tensile Modulus ◽  
Gauge Length ◽  
Efficiency Factor ◽  
Low Density ◽  
Tensile Stiffness ◽  
Lower Tensile Strength

AbstractFor the mechanical properties of paper, tensile testing has been widely used. Among the tensile properties, the tensile stiffness has been used to determine the softness of low-density paper. The lower tensile stiffness, the greater softness of paper. Because the elastic region may not be clearly defined in a load-elongation curve, it is suggested to use the tensile modulus which is defined as the slope between the two points in the curve. The two points which provide the best correlation with subjective softness evaluation should be selected. Low-density paper has a much lower tensile strength, but much larger elongation at the break. It undergoes a continuous structural change during mechanical testing. The degree of the structural change should depend on tensile conditions such as the sample size, the gauge length, and the rate of elongation. For low-density paper, the tensile modulus and the tensile strength should be independent of each other. The structure efficiency factor (SEF) is defined as a ratio of the tensile strength to the tensile modulus and it may be used a guideline in developing superior low-density paper products.

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