Tensile properties of elastomers

Smith,T.L., Frederick, . E. Ultimate tensile properties of elastomers. IV. Dependence of the failure envelope, maximum extensibility, and equilibrium stress-strain curve on network characteristics. J. Appl. Phys. 36,2996-3005 (1965). 

The presence of a higher aromatic content In the gasoline resulted In Increased swell and hence Increased deterioration of tensile properties of elastomers exposed to the gasoline and Its mixtures. Addition of benzene to Increase the aromatic content resulted In slightly more detrimental effects on nitrile elastomers than the addition of toluene. The data on all elastomers can be explained In terms of the solubility parameter concept. 

Mixtures on the Volume Swell and Tensile Properties of Elastomers. 

The influence of strain rate and temperature on the tensile properties of elastomers and amorphous polymers has been studied extensively, particularly by Smith and co-workers [154-156], who measured the variation of tensile strength and ultimate stain as a function of strain rate for a number of elastomers. The results for different temperatures could be superimposed, by shifts along the strain rate axis, to give master curves for tensile strength and ultimate strain as a function of strain rate. Results of this nature are shown in... 

Desirable properties of elastomers include elasticity, abrasion resistance, tensile strength, elongation, modulus, and processibiUty. These properties are related to and dependent on the average molecular weight and mol wt distribution, polymer macro- and microstmcture, branching, gel (cross-linking), and... 

Speckhard T.A. and Cooper S.L., Ultimate tensile properties of segmented pol3furethane elastomers Factors leading to reduced properties for pol3mrethane based on nonpolar soft segments. Rubber Chem. TechnoL, 59, 405, 1986. 

Elastic Modulus, Network Structure, and Ultimate Tensile Properties of Single-Phase Polyurethane Elastomers... 

Improvement of the mechanical properties of elastomers is usually reached by their reinforcement with fillers. Traditionally, carbon black, silica, metal oxides, some salts and rigid polymers are used. The elastic modulus, tensile strength, and swelling resistence are well increased by such reinforcement. A new approach is based on block copolymerization yielding thermoelastoplastics, i.e. block copolymers with soft (rubbery) and hard (plastic) blocks. The mutual feature of filled rubbers and the thermoelastoplastics is their heterogeneous structure u0). 

The effects of ethanol/gasollne and MTBE/gasollne mixtures on swell and tensile properties of selected automotive elastomers were determined and compared to those of methanol/gasollne mixtures. 

Duvdevani(40) have been directed at modification of ionomer properties by employing polar additives to specifically interact or plasticize the ionic interactions. This plasticization process is necessary to achieve the processability of thermoplastic elastomers based on S-EPDM. Crystalline polar plasticizers such as zinc stearate can markedly affect ionic associations in S-EPDM. For example, low levels of metal stearate can enhance the melt flow of S-EPDM at elevated temperatures and yet improve the tensile properties of this ionomer at ambient temperatures. Above its crystalline melting point, ca. 120°C, zinc stearate is effective at solvating the ionic groups, thus lowering the melt viscosity of the ionomer. At ambient temperatures the crystalline additive acts as a reinforcing filler. 

Tensile properties of composite propellants depend on the tensile properties of the matrix, concentration of the components, particle size, particle-size distribution, particle shape, quality of the interface between fillers and polymeric binder, and, obviously, experimental conditions (strain rate, temperature, and environmental pressure). Many authors (2, 3) have explained the effect of fillers on the mechanical properties of composites, the importance of the filler-matrix interface on physical properties, and the mechanism of reinforcement of the material. Other efforts have examined the effect of experimental conditions on the failure properties of filled elastomers. Landel and... 

Tensile strength is an important mechanical property of elastomer. Five kinds of EPDM in the experiment kept the higher tensile strength at lOMGy than initial values showing the durability of the samples for irradiation. 

Resistance of elastomers to degradation in hot and humid environments was studied by employing accelerated aging tests in which tensile properties of specimens immersed continuously in water at elevated temperatures were monitored (Table V Examples of hydrolytic aging data for several materials are shown in Figures... 

While true miscibility may not be required for elastomer properties, adhesion between the immiscible phases is required. Immiscible polymer blends that fulfill this criteria provide a significant opportunity to change the rheological, tensile, and wear properties of elastomer blends compared to miscible blends. 

A peroxide-induced reactive compounding of PP/GRT blends in a corotating twin-screw extruder was carried out to prepare thermoplastic elastomer alloys (Wiessner et al., 2012). The extrusion experiments showed that the width of the residence time distribution was the key parameter determining the mechanical properties of elastomer alloys, whereas the mean residence time had little effect. This was confirmed by performing both quasi-static and cyclic tensile tests. 

Viscoelastic properties of elastomer-based CPNCs were measured at a constant frequency of 1 Hz as a temperature sweep of the dynamic moduli. Exfoliated CPNCs with polybutadiene (PBD) or polyisoprene (IR) matrix were prepared by in situ anionic polymerization, with Tg increasing by about 10°C upon incorporation of 6.2 wt% organoclay [Liao et al 2005,2006]. However, contrary to expectations, these CPNCs did not show improved dynamic tensile storage modulus, E. ... 

Addition of fillers can dramatically change mechanical properties of elastomer materials. For example, a pure gum vulcanizate of general purpose styrene-butadiene rubber (SBR) has a tensile strength of no more then 2.2 MPa but, by mixing in 50 parts per hundred weight parts of rubber (p.p.h.r) of a active CB, this value rises more than 10 times to 25 MPa. How CB, being fine powder of practically no mechanical strength, can make reinforcement in rubbers, similar to... 

D 395 Test Method for Rubber Property - Compression Set D 412 Test Method for Vulcanized Rubber, Thermoplastic Rubbers and Thermoplastic Elastomer - Tension D 471 Test Method for Rubber Property - Effect of Liquids D 570 Test Method for Water Absorption of Plastics D 624 Test Method for Tear Strength of Conventional Vulcanized Rubber and Thermoplastic Elastomer D 638 Test method for Tensile Properties of Plastics D 792 Test Method for Specific Gravity (Relative Density) and Density of Plastics by Displacement... 

Properties of Fluoroelastomers. FKM elastomers can have reasonably low glass transition temperatures, in the range of-18 to -40°C. The tensile properties of fluoroelastomers vulcanizates are fairly good but can decrease considerably with increasing temperatures. 

As much as 30% of all polyolefin products involve blends (Robeson 2007). It has been found, for example, that blending metallocene-catalyzed linear low-density polyethylenes (mLDPEs) with HDPE improves the Izod impact strength and some tensile properties of HDPE. Adding mLLDPE to LDPE increases the ductility of LDPE (Cran and Bigger 2009). In general, PE blends can be divided into three categories (1) PE lots blended to meet standard specifications for density and melt flow, (2) PE modified with <15 wt% of other polymer(s), and (3) PE bends with other thermoplastics or thermoplastic elastomers. 

Table 7.5. Tensile Properties of SINs Containing 10% Castor Oil Elastomer at...

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