Maximum stress at break

Binder Binder Composition Maximum Maximum Stress at Break... 

The mechanical properties of PA-based polymers can also be enhanced through the incorporation of inorganic micro- and nanofillers such as silica nanoparticles. Thus, the maximum value of stress at yield point (72 MPa) was observed in hybrid materials containing 10 wt% silica and the maximum stress at break point increased up to 66 MPa in PA-sUica hybrids containing 20 wt% silica (compared with 44 MPa for the silica-free PA system). Also, the tensile modulus was found to increase up to 2.59 GPa upon incorporation of 10 wt% silica within the polymeric matrix [268]. 

TPE block copolymers having semicrystalline LLA terminal blocks and an amorphous heterogeneous middle block were prepared from DXO and TMC using a five-membered tin oxide initiator. All the copolymers exhibited highly elastic behavior with a maximum stress at break of 35.6 MPa for a copolymer having no DXO and maximum strain at break 1089% when the ratio DXO TMC LLA was 200 200 200 [133]. 

Tensile testing results as a function of MMT weight and volume content. Top the Young s modulus normalized by the bulk value (68.5 MPa) middle the maximum stress at break bottom the toughness of the hybrids normalized by the bulk values (45.8 kJ/m ). Copyright Chem. Mater. 2000, vol. 12, pp. 2943-2949. 

Two types of mechanical tests have been used the low rate of deformation tensile, compressive or bending tests and the high speed impact tests. Immiscibility of polymers is reflected in both. For example, in tensile tests the maximum strain at break (or the maximum elongation), and the yield stress (or the maximum strength) can be... 

Polyamides and polyesteramides are more recent arrivals to the commercial biodegradable polymer field. Copolymers of either glycine or serine with e-aminocaproic acid are biodegradable. For example, biodegradable polyaspartic acid was synthesized (95% yield) at low cost [Koskan, 1992]. A copolymer of butylene-adipate and e-caprolactam was recently introduced by Bayer as BAK 1095. The material has T = 125°C, density of 1070 kg/m, tensile modulus of 180 MPa, maximum strain at break of 400%, tensile stress at break of 25 MPa, and it fully degrades in 300 days under the ASTM standard conditions. 

Tensile stress at yield first stress at which an increase in strain occurs without an increase in stress. Also referred to as yield stress Tensile stress at break the tensile stress at which the test specimen ruptures Tensile strength the maximum tensile stress sustained by the test specimen during a tensile test... 

Based on the stress-strain diagram the values tensile stress at yield cXy and tensile strength at maximum (7m as well as the associated normative yield strain and nominal strain 8tM or normative strain 8m at tensile strength as well as strain at break 8b can be calculated (Eqs. 4.6. 11). For completely recorded diagrams the nominal strain at break 8tB can be determined additionally (Eq. 4.12). Because of the dependence on software and test equipment, especially sampling rate, the tensile stress at break (Tb should not be used (Eq. 4.13). Due to the viscoelastic behaviour of the plastics modulus of elasticity in tension is determined as secant modulus between the strain limits of 0.05 % and 0.25 % (Eq. 4.14). If the transverse strain is recorded simultaneously using strain gauges Poisson ratio jl can be calculated (Eq. 4.15). 

As Fig. 2 illustrates, the stress at break (or yield) of the compatible Copolymer B blends rises to a maximum at between 60 and 80% PPO. This apparent enhancement in strength has been observed in the case of polymers antiplasticized by low molecular weight additives (14) and suggests that the compatible copolymers act as polymeric antiplasticizers for PPO. This analogy to antiplasticization has been applied to other compatible polymer blends (15,16). Similar synergistic dependence of tensile strength on blend composition for PS/PPO blends has been reported (13,17). In a study of... 

Polymer blends must provide a variety of performance parameters. Usually it is a set of performance criteria that determines if the material can be used or not For specific apphcatimi more weight can be given to one or another material property. The most important properties of polymer blends are mechanical. Two types of tests have been used the low rate of deformation (tensile, compressive, or bending) and the high-speed impact Inuniscibility affects primarily the maximum elongation at break and the yield stress. 

Ultimate strength n. The maximum nominal stress a material can withstand when subjected to an applied tensile, compressive, or shear load. If the mode of loading is not specified, it is assumed to be tensile. In materials that exhibit a definite yield strength, ultimate strength will usually mean the nominal stress at break, which can be less than the maximum. Shah V (1998) Handbook of plastics testing technology. John Wiley and Sons, New York. 

Emulsion polymerization of pyrrole was also used to prepare blends of polypyrrole with a poly(alkyl methacrylate) [95]. A chloroform solution of a poly-(alkyl acrylate) and pyrrole was dispersed in an aqueous surfactant solution generating an emulsion. An aqueous solution of an oxidant was added to the emulsion with stirring, polymerizing pyrrole. The precipitated blend could be hot pressed in the form of films with conductivities of 6-7Scm . The curve for the variation of the conductivity of the blend with the oxidant/pyrrole ratio shows a maximum at a ratio of two with subsequent decrease. However, the yield increases to nearly 100% up to a ratio of four. The percolation threshold is approximately 10 wt% of pyrrole. The type and the concentration of the surfactant also affect the yield and conductivity. The mechanical properties of the blend depends on the number of carbons in the alkyl chain of the insulating polymer host. The strain at break of hot-pressed films increases and the stress at break decreases in the direction methyl, ethyl, butyl (Figure 18.3). This is an example where the mechanical properties of the conductive blend could be tailored according to the alkyl substituent in the poly(alkyl methacrylate) used in its preparation. 

If the phase morphology is fine disperse, the particle distances are reduced and the stress state is changed to a one-dimensional stresses. If the dispersed phase has no intensive interactions with the matrix, than the PP matrix fibrillates between the drops. This mechanism leads to higher specimen deformability, thus higher maximum extension at break. 

In dilute solution, degradation can occur as a result of molecular stresses developed by hydrodynamic shear [42, 43]. From the Frenkel hypothesis of maximum stress at midchain, it was deduced that the breaking point should be narrowly localized near the center bond. However, for a broad initial MWD, the final product cannot have a perfectly sharp distribution with the largest molecules approximately twice the length of the smallest. The average mechanical force per moleculefrom the force t per unit area... 

Tensile Ultimate Strength n the maximum tensile stress subjected to the test specimen during the tensile test. The value can be identical with the tensile stress at break. 

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