scholarly journals Synthetic Environmentally Friendly Castor Oil Based-Polyurethane with Carbon Black as a Microphase Separation Promoter

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1333 ◽  
Author(s):  
Jia-Wun Li ◽  
Wen-Chin Tsen ◽  
Chi-Hui Tsou ◽  
Maw-Cherng Suen ◽  
Chih-Wei Chiu

This study created water polyurethane (WPU) prepolymer by using isophorone diisocyanate, castor oil, dimethylolpropionic acid, and triethanolamine (TEA) as the hard segment, soft segment, hydrophilic group, and neutralizer, respectively. TEA, deionized water, and carbon black (CB) were added to the prepolymer under high-speed rotation to create an environmentally friendly vegetable-oil-based polyurethane. CB served as the fortifier and promoter of microphase separation. Fourier transform infrared spectroscopy was performed to elucidate the role of H-bond interactions within the CB/WPUs. Additionally, atomic force microscopy was conducted to determine the influence of H-bond interactions on the degree of microphase separation in the WPU. Furthermore, this study used four-point probe observation to discover the materials’ conductivity of CB in the WPU. Thermogravimetric analysis and dynamic mechanical analysis were performed to measure the thermal properties of the CB/WPUs. The mechanical properties of CB/WPUs were measured using a tensile testing machine. The CB/WPUs were also soaked in 1 wt.% NaOH solution for different amounts of time to determine the degradation properties of the CB/WPUs. Finally, scanning electron microscopy was performed to observe the topography of the CB/WPUs after degradation.

2013 ◽  
Vol 812 ◽  
pp. 192-197
Author(s):  
Wuttison Yasinee ◽  
Thongyai Supakanok ◽  
Wacharawichanant Sirirat ◽  
Piyasan Praserthdam

Acrylonitrile-butadiene rubber (NBR) or nitrile rubber is an unsaturated copolymer of butadiene and acrylonitrile. NBR has been widely used for fuel hoses, seals and gaskets due to its excellent oil and fuel resistance. Aiming to develop NBR which has resistance to oxygenated solvent, NBR with acrylonitrile content of 34 wt%, was blended with Acrylonitrile-butadiene-styrene (ABS) and Poly (Styrene-co-Acrylonitrile) (SAN) as binary polymer systems. The NBR/ABS and SAN blends were prepared by mechanical blending in the composition of 80/20, 70/30 and 60/40 w/w. The effects of ABS or SAN content on mechanical, morphological and thermal properties were investigated and compared with commercials NBR. Mechanical properties were determined using the tensile testing machine. The morphologies of polymer blends were investigated using scanning electron microscope (SEM). The thermal properties were examined using differential scanning calorimeter (DSC), thermal gravimetric analysis (TGA) and dynamic mechanical analysis (DMA). It has been found that percent compatibility of ABS and SAN into NBR rich phase are 2.69 and 1.53 wt% respectively.


Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1053
Author(s):  
Cunli Zhu ◽  
Nan Zhou ◽  
Yaben Guo ◽  
Meng Li ◽  
Qiangqiang Cheng

Shotcrete material has found extensive applications as a reinforcing material in the engineering sector. This study examined the effect of doped glass fibers on the mechanical performance of the modified shotcrete material composed of aeolian sand, fly ash, cement, quicklime, and doped glass fibers. Its tensile and shear strengths values were experimentally determined via a WAW-1000D computerized hydraulic universal tensile testing machine. Its microstructure was analyzed via a size analyzer, scanning electron microscope (SEM), and X-ray diffractometer (XRD). A 2D simplified mechanical model was elaborated to reflect the influence mechanism of the doped glass fibers on the mechanical performance of the modified shotcrete material. The experimental and mechanical analysis results indicated that, at the macroscopic scale, the experimental tensile and shear strengths of the shotcrete material doped with glass fibers were significantly higher than those of the undoped shotcrete material (by up to 310% and 596%, respectively). These results were in concert with the proposed model predictions, where the compound stresses in the shotcrete material were derived as the sum of the stress borne by the shotcrete material itself and the bridging stress exerted by the glass fibers. At the microscopic scale, SEM observations also revealed that the glass fibers were intertwined with each other and tightly enveloped by the shotcrete material particles within the modified shotcrete specimens, connecting the particles of different components into a whole and improving the overall mechanical strength. In addition, the relationships of the compound stress of the shotcrete material vs. embedment length, embedment angle, and cross-sectional area of the glass fibers were established. The research findings are considered instrumental in clarifying the mechanism by which the glass fibers influence the mechanical performance of shotcrete materials and optimize their solid waste (fly ash and quicklime) utilization.


2021 ◽  
Vol 1035 ◽  
pp. 114-118
Author(s):  
Chang Liang Shi ◽  
Yan Ping Niu ◽  
Yi Min Lin ◽  
Quan Hu ◽  
Xin Zhang

The effects of coarse-grained ring on the mechanical properties and cutting performance of 2011 aluminum alloy extruded bars were studied by metallographic microscope, scanning electron microscope, tensile testing machine and high-speed lathe. The results show that the microstructure of aluminum alloy extruded bar was composed of α-Al phase, Al7Cu2Fe phase, CuAl2 phase and SnBi eutectic phase. There was a coarse-grained ring in the aluminum alloy extruded bar. The coarse-grained ring reduced the mechanical properties and cutting performance of the aluminum alloy extruded bar. The aluminum alloy extruded bar with a diameter of 30 mm had a coarse-grained ring depth of 9 mm and lower mechanical properties, whose the tensile strength was 287.9 MPa, the elongation was 17%, the cutting performance was poor and the chips were long. The aluminum alloy extruded bar with a diameter of 40 mm had a coarse-grained ring depth of 1 mm, higher mechanical properties and better cutting performance, whose the tensile strength was 394.5 MPa, the elongation was 23.5%, the chips were fine and uniform.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 772
Author(s):  
Andrzej Grządziela ◽  
Marcin Kluczyk

The technical requirements for naval ships machine foundations are far more strict in comparison to merchant’s vessels. These requirements are confirmed in the military standardization of many countries. Underwater Explosion (UNDEX phenomena) detonation pulses, force naval engineers to design and implement different shock absorbers made from a wide variety of materials. This study presents the tests results of typical shock absorber designs made of various types of rubber and elastomers. The initial objective of the study was to determine the energy absorption of shock impacts, the choice of materials capable of operating within the temperature range of 0 °C to 70 °C, resistance to contact with oils and marine fuel, performance at frequencies ranging from 5 to 30,000 Hz, and absorption no less than 40% of harmonic vibration energy. Initial studies conducted on tensile testing machine were used to determine the static and dynamic stiffness of a shock absorbers. Considerations of stiffness coefficient for the linear and nonlinear range is typical for shock pulses. Further tests were carried out on a lightweight drop hammer to determine the characteristics of the damping coefficient for high-speed wave interactions—Shock Response Spectrum (SRS). The final aim of the study was to assess the repeatability of the shock absorbers response to multiple impact loads. Mechanical properties describing possibilities of tested dampers materials to absorb energy of UNDEX were also presented.


2017 ◽  
Vol 18 (3) ◽  
pp. 561-561
Author(s):  
B. Ruan ◽  
G. Q. Li ◽  
Y. Chen ◽  
P. Mitrouchev ◽  
B. He ◽  
...  

2012 ◽  
Vol 509 ◽  
pp. 40-45
Author(s):  
Dan Yang Dong ◽  
Yang Liu ◽  
Lei Wang ◽  
Chang Sheng Liu

To reduce fuel consumption and greenhouse gas emission, dual phase (DP) steels have been considered for automotive applications due to their higher tensile strength, better initial work hardening along with larger elongation compared to conventional grade of steels. In such applications, which would create potential safety and reliability issues under dynamic loading, the mechanical behavior of DP steel considering the strain rate must be examined. In the present study, the dynamic tensile behavior of DP600 steel sheets was investigated using a high-speed tensile testing machine at various strain rates. And the quasi-static tensile testing was also conducted on the steel to understand the effect of the strain rate on the tensile property. The fracture mechanisms of the steel were also analyzed. The results show that the mechanical properties of DP600 steel are noticeably influenced by the strain rates. As the strain rate increases, the strength of the steel increases and the obvious yield phenomenon can be observed when the strain rate is above 0.01 s-1. The fracture elongation of DP600 steels decreases with increasing strain rate from 0.001 to 1 s-1, then increases up to the strain rate of 100 s-1 and reaches the lowest value at the strain rate of 1000 s-1. DP600 steel sheet exhibit typical ductile fracture characteristics with dimples morphology of the facture surface when tensile deformed at various strain rates.


2011 ◽  
Vol 704-705 ◽  
pp. 1423-1428 ◽  
Author(s):  
Ning Bo Li ◽  
Jing Pei Xie ◽  
Wen Yan Wang

By means of wear analysis of the wear-resistant steel used in the process, and adjust the wear-resistant steel composition, by adding alloying elements Cr, Mo and so on, optinlizing heat treatment technique, to get new wear-resistant steel. The HR-150A rock well hardness tester and JB-300B impact tester as well as SHIMADZUAG-I250KV on electronic tensile testing machine were used to test the mechanical properties of materials. In the test of friction and wear performance was done using the high temperature and high-speed friction of wear-testing maching (MMS-1G), and analysis of microscopy and the wear morphology by JSM-5610LV SEM.The results showed that: The hardness of new wear-resistant steel reaches HRC53, the impact toughness 23J/cm2, And at this moment, the sample matrix is the microstructure of small lath martensite and residual austenite.


2021 ◽  
Author(s):  
Fangyuan Zhang ◽  
Anling Li ◽  
Wuyun Zhao

Abstract The paper mulch will inevitably suffer the influence of the acidic or alkaline environment during the usage. To evaluate the influence of the acidic or alkaline environment on the corrosion resistance of the paper film, we investigate the method of immersing the paper film with acid and alkali solution. We use the hydrophobic SiO2 to prepare a superhydrophobic paper mulch with a contact angle of 155° with water. Two kinds of superhydrophobic paper mulch were put into H2SO4 solution with pH 4.6 and NaOH solution with pH 8.5, respectively. After soaking for 48h, we use a contact angle tester, a tensile testing machine, and a high-speed camera to compare the contact angle, mechanical properties, and bounce performance of these two paper mulches. The results showed that the tensile strength and droplet bounce height of the superhydrophobic paper mulch decreased after being soaked in the acid or alkaline solution for 48 hours. The mass-loss rate of the paper mulch in acid solution is more significant, and its contact angle is still greater than 145° which treats as a good bounce performance. The microscopic morphology of the paper showed that SiO2 can form a superhydrophobic structure on the surface of the paper mulch. The method is simple and environmentally friendly and can solve the problem of poor acid and alkali corrosion resistance of the paper mulch. It has extraordinary significance in reducing the environmental pollution.


2008 ◽  
Vol 385-387 ◽  
pp. 749-752 ◽  
Author(s):  
Seok Bong Kim ◽  
Hoon Huh

This paper deals with the dynamic failure elongation of mild steel, SGACD and advanced high strength steel sheets such as TRIP600, DP600 and TWIP steels. The failure elongation has been obtained from the high speed tensile testing machine with various strain rates ranged from 0.003/s to 200/s. The experimental result demonstrates that the tensile elongation does not simply decrease as the strain rate increases, but it decreases from the quasi-static state to the strain rate of 0.1 or 1/s and increases again up to the strain rate of 100/s. Furthermore, some high strength steels have the tendency that the tensile elongation increases as the strain rate increases. Moreover, the localized strain rate hardening in the necking region induces the increase of elongation.


2014 ◽  
Vol 783-786 ◽  
pp. 168-173
Author(s):  
Keitaro Horikawa ◽  
Shunsuke Hokazono ◽  
Hidetoshi Kobayashi

We have developed a new testing device, which is capable of detecting hydrogen gas evolution from the microstructural changes at the same timing. The device is composed of the tensile testing machine equipped with a high-speed microscope and two types of quadrupole mass spectrometers installed in the ultrahigh vacuum chamber. Sampling rate of microscopic observation is 2000 fps. Hydrogen or deuterium was pre-charged to the 7075 aluminum alloy by means of the slow strain rate deformation, together with the exposure under the humid air atmosphere. The hydrogen amount was measured by using a thermal desorption analysis in advance. As a result, it was revealed that hydrogen gas was evolved when the surface crack was generated around the notch root of the test specimen. SEM observation also showed that the initial crack is related to the propagation of grain boundary fracture around the notch root. When compared to the microstructure and the hydrogen gas evolution near the notch root, the hydrogen amount evolved at the grain boundary was estimated to be about 3.0×10-7mol/m2.


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