Improvement of Mechanical Properties of Unsaturated Polyesters by Acrylonitrile

1992 ◽  
Vol 31 (3-4) ◽  
pp. 221-227 ◽  
Author(s):  
G[ubar]ng[obar]r G[ubar]nd[ubar]z ◽  
Adnan Deniz
2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yeşim Müge Şahin ◽  
Gökhan Çaylı ◽  
Jesmi Çavuşoğlu ◽  
Emre Tekay ◽  
Sinan Şen

As an alternative resin to conventional synthetic unsaturated polyesters (UPEs), epoxidized maleinated castor oil (EMACO) was synthesized in two steps. For this purpose, castor oil was reacted with maleic anhydride at 70°C to obtain maleinated castor oil (MACO). Then, epoxidation of MACO was carried out by using a mixture of formic acid and hydrogen peroxide at 0–5°C. Then, the free carboxyl groups of the synthesized EMACO were further reacted with free epoxide groups of EMACO at 90°C. At the end of the reaction, an unsaturated polyester precursor-prepolymer was obtained (P-EMACO). FTIR and1H NMR spectroscopic techniques were used to characterize the monomers synthesized. The P-EMACO was then mixed with styrene and cross-linked in the presence of AIBN at 50°C. Thermal and mechanical properties of the final cross-linked product were investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) techniques. The degradation onset temperature of the material at which cross-linked X-EMACO loses 5% of its weight was found to be 209°C. Its dynamicTgand storage modulus at 25°C were determined as 72°C and 1.08 GPa, respectively. These results are higher than some of the different oil based polymers reported in the literature.


2014 ◽  
Vol 607 ◽  
pp. 547-550
Author(s):  
Yi Chu Hsu ◽  
Po Yuan Cheng ◽  
Hsiao Wei Lee ◽  
Shun Fua Su

We investigated two processes to fabricate unsaturated polyesters, UP, to serve as a stamp to emboss a microfluidic chip to apply to a peristaltic micropump. The mechanical properties of UP are great to apply to vibration type micro-actuators. However, it’s rarely discussed academically. As a result, we proposed two processes developed and compared macro-and micro-scopically. It was first observed that process I of traditional UP curing process and process II of modified process can both replicate the geometries of microfludic chips well macroscopically. In addition, the former one has macroscopic defaults like cracks, bend, and separation between vessel and UP molds, while the latter one doesn’t. Optical microscope and confocal microscope are also applied to verify the replication effects microscopically. Again, both processes illustrate good replication results with variation of both lengths and areas all less than 10%, while process II has better geometries and lower deviation on different sites. The process I was proven that the averages of depth and widest width change rates for replication are-1.06% (between-4.15% and 2.89%) and-2.77% (between-6.93% and 0.67%), respectively. And, the replication results of process II shows also reasonable change and even smaller deviations that the averages of depth and widest width change rates are-4.77% (between-6.33% and-3.84%) and 1.53% (between 1.15% and 2.15%), respectively.


Author(s):  
S. Fujishiro

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.


Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).


Author(s):  
D. R. Clarke ◽  
G. Thomas

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.


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