Young's Modulus and Dynamic Mechanical Properties of San Resins Modified with Ethylene-Propylene Rubber

1978 ◽  
Vol 51 (4) ◽  
pp. 655-667 ◽  
Author(s):  
A. Brancaccio ◽  
L. Gargani ◽  
G. P. Giuliani

Abstract The dependence of Young's modulus and dynamic mechanical properties of a new high impact resin, ATS (acrylonitrile-styrene copolymer polymerized in the presence of ethylene-propylene-triene terpolymer), on the composition and morphology of the dispersed phase is examined and compared to that of ABS resins (acrylonitrile-styrene copolymer polymerized in presence of polybutadiene). The relationship between modulus and composition is different for the two resins because of the different morphology of the rubbery phases. The experimental results are compared to the predictions of several mathematical models. This analysis is extended to the dynamic moduli E′ and E″, measured over a wide range of temperatures covering the main transition of the rubbery phases.

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hui Li ◽  
Chi Dong ◽  
Hongwei Yu ◽  
Xin Zhao ◽  
Yan Li ◽  
...  

Rock mechanical properties are critical for drilling, wellbore stability, and well stimulation. There are usually two laboratory methods to determine rock mechanical properties: static compression tests and acoustic velocity measurements. Rocks are heterogeneous, so there are significant differences between static elastic constants and the corresponding dynamic ones. Usually, static test results are more representative than dynamic methods but the static tests are time consuming and costly. Dynamic methods are nondestructive and less expensive, which are practical in the laboratory and field. In this paper, we compare the static and dynamic elastic properties of Eagle Ford Shale by triaxial compressive tests and ultrasonic velocity tests. Correlations between static and dynamic elastic properties are developed. Conversion from dynamic mechanical properties to static mechanical properties is established for better estimating reservoir mechanical properties. To better understand the relationship of static and dynamic mechanical properties, 30 Eagle Ford Shale samples were tested. According to the test results, the dynamic properties are considerably different from the static counterparts. For all tested samples, static Young’s modulus is lower than dynamic Young’s modulus, ranging from 55% to 90%. The difference of the static and dynamic Young’s moduli decreases with the increasing of confining pressure. The reason may be because the microcracks closed in high confining pressure. Correlations between static and dynamic Young’s modulus are developed by regression analysis, which are crucial to understand the rock mechanical properties and forecast reservoir performance when direct measurement of static mechanical properties is not available or expensive. There are no strong correlations between static and dynamic Poisson’s ratios observed for the tested samples. Two potentially major reasons for the discrepancy of the static and dynamic properties of Eagle Ford Shale are discussed. Lithology and heterogeneity may be the inherent reasons, and external causes are probably the difference in strain amplitude and frequency.


2002 ◽  
Vol 10 (5) ◽  
pp. 381-390 ◽  
Author(s):  
Viviane Xavier Moreira ◽  
Bluma Guenther Soares

Rubber blends containing nitrile rubber (NBR) and ground ethylene-vinyl acetate copolymer waste (EVAW) from the footwear industry have been prepared over a wide range of composition (up to 90 phr of waste component). The ground EVAW had particle size in the range of 100-350 mm and a gel content of 60±5%. The effect of different amounts of EVA waste on the tensile strength, elongation at break, hardness, tear strength and dynamic mechanical properties was studied. EVAW had a good reinforcing effect on the NBR matrix. A combination of optimum tensile properties, resistance to solvent penetration and dynamic mechanical properties, such as storage modulus and loss tangent was achieved by introducing 50 phr of EVAW in the NBR matrix. This composition also presents a more uniform morphology, as indicated by scanning electron microscopy.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
T. A. Dung ◽  
N. T. Nhan ◽  
N. T. Thuong ◽  
D. Q. Viet ◽  
N. H. Tung ◽  
...  

The dynamic mechanical behavior of modified deproteinized natural rubber (DPNR) prepared by graft copolymerization with various styrene contents was investigated at a wide range of temperatures. Graft copolymerization of styrene onto DPNR was performed in latex stage using tert-butyl hydroperoxide (TBHPO) and tetraethylene pentamine (TEPA) as redox initiator. The mechanical properties were measured by tensile test and the viscoelastic properties of the resulting graft copolymers at wide range of temperature and frequency were investigated. It was found that the tensile strength depends on the grafted polystyrene; meanwhile the dynamic mechanical properties of the modification of DPNR meaningfully improved with the increasing of both homopolystyrene and grafted polystyrene compared to DPNR. The dynamic mechanical properties of graft copolymer over a large time scale were studied by constructing the master curves. The value of bT has been used to prove the energetic and entropic elasticity of the graft copolymer.


Author(s):  
Rodrigue Matadi Boumbimba ◽  
Said Ahzi ◽  
Nadia Bahlouli ◽  
David Ruch ◽  
José Gracio

Similarly to unfilled polymers, the dynamic mechanical properties of polymer/organoclay nanocomposites are sensitive to frequency and temperature, as well as to clay concentration. Richeton et al. (2005, “A Unified Model for Stiffness Modulus of Amorphous Polymers Across Transition Temperatures and Strain Rates,” Polymer, 46, pp. 8194–8201) has recently proposed a statistical model to describe the storage modulus variation of glassy polymers over a wide range of temperature and frequency. In the present work, we propose to extend this approach for the prediction of the stiffness of polymer composites by using two-phase composite homogenization methods. The phenomenological law developed by Takayanagi et al., 1966, J. Polym. Sci., 15, pp. 263–281 and the classical bounds proposed by Voigt, 1928, Wied. Ann., 33, pp. 573–587 and Reuss and Angew, 1929, Math. Mech., 29, pp. 9–49 models are used to compute the effective instantaneous moduli, which is then implemented in the Richeton model (Richeton et al., 2005, “A Unified Model for Stiffness Modulus of Amorphous Polymers Across Transition Temperatures and Strain Rates,” Polymer, 46, pp. 8194–8201). This adapted formulation has been successfully validated for PMMA/cloisites 20A and 30B nanocomposites. Indeed, good agreement has been obtained between the dynamic mechanical analysis data and the model predictions of poly(methyl-methacrylate)/organoclay nanocomposites.


2008 ◽  
Vol 33-37 ◽  
pp. 681-686
Author(s):  
Tao Hua ◽  
Hui Min Xie ◽  
Peng Zhang ◽  
Fei Yi Du ◽  
Bing Pan ◽  
...  

The spider silk is considered as a new type of biomaterials with its excellent mechanical properties. The mechanical properties of the spider silk are crucial to their applications. In this study the mechanical properties of spider silk were studied with a micro-tensile system driven by magnet-coil force actuator, which is very effective to measure the properties of low dimensional materials. The Young’s modulus of the spider silk is obtained, the relationship between the mechanical properties of spider silk and time is also acquired.


Sign in / Sign up

Export Citation Format

Share Document