Very low modulus

Incidentally, as is well known, in the unvulcanized state of the filled mbber, the stress upturn does not appear even in the carbon content of = 0.2-0.25. For understanding this phenomenon, we must consider the discontinuity between the SH layers, in addition to the very low modulus of the unvulcanized mbber. Actually, as we discussed earlier, carbon blacks disperse as an aggregate of carbon particles, then the continuity of carbon gels consisting of aggregates must be much poorer than the theoretical calculation based on the perfect dispersion of carbon particles. In this case, the stress cannot be transmitted from carbon gel to carbon gel through such a very soft medium, and as a result, the stress-strain curve of the system is rather similar to the characteristics of the... 

Applying this equation to elastomer composites, considerable simplification is possible. Because the elastomeric matrix has very low modulus and high elasticity, a can be assumed to be nearly zero. The resulting equation is then ... 

The details of these systems are still quite proprietary but it s sufficient to say that controlled crosslinking is possible. Very low modulus, high elongating sealants are available which... 

Another key limitation of Z-N catalysts is the inability to incorporate very high levels of alpha-olefin comonomer such as 1-butene, 1-hexene, or 1-octene to make the density less than about 0.885 g/cm. The lowest density Z-N catalyzed VLDPE resin commercially available today (FLEXOMER from The Dow Chemical Company) has a target density of 0.885 g/cm (approximately 20 wt% crystallinity). Due to this, Z-N catalyzed VLDPE resins cannot be used in applications requiring very low modulus, low shore A hardness (density less than 0.885 g/cm ). Note that logarithm of modulus of polyethylene resins is related to density (degree of crystallinity) ... 

Of course, the ability to dissipate energy is only one of the characteristics concerned in toughness, or the ability to resist fracture (see Section 3.2). Thus the modulus itself contributes to the total energy and the stress required for fracture a particulate filler may, by raising the modulus of a very low-modulus polymer, increase the toughness. 

Polycaprolactone (PCL) is a biodegradable semicrystalline polyester that is synthesized from cap-rolactone using staimous octoate in a similar maimer to polylactide or polyglycolide. PCL has a very low modulus of around 50 ksi since it has a low Tg of —60 C. PCL degrades very slowly, and therefore, it is usually not used as a homopolymer. Caprolactone, however, is copolymerized with glycolide to make a flexible suture material (trade name Monocryl). ... 

As expected, the tensile modulus of LI is greater than the tensile modulus of SI and of S2 because of the very low modulus in tension characterising the core material. The intermediate value for S2 between SI and LI is certainly due to the fact that compared with SI, S2 has one more layer of WR, which has a greater tensile modulus than CSM. Also the total weight fraction of fibres for S2 is greater than for SI. 

Take a very rigid material, like glass, and bond two pieces together using a very low modulus adhesive. The low modulus will encourage any stress to be distributed uniformly over the bond area. The objective in structural bonding is to transfer and distribute stress and strain in such a way that the integrity of the structure is maintained. 

A base glass composed of Ca0 P205 = 0.85 (molar ratio) was used to produce these fibers. Crystallization took place at 600 C for 48 h. Unidirectional crystallization techniques were not conducted. Crystallization of P-Ca(P03)2 proceeded in needle form, with random orientation yielding an isotropic body. An ultraphosphate of the substantially lower chemical durability of the glass matrix and the ultraphosphate crystals compared with that of the P-Ca(P03)2, the matrix was easily extracted by aqueous leaching. These P-Ca(P03)2 fibers were subsequently used in a composite material with a very low modulus of elasticity (Kasuga 1996). 

Superelasticity Minimal stress increase beyond the initial strain region resulting in very low modulus... 

Specially designed polyamides with high melt points, but very low modulus, serve to encapsulate electrical connectors. This type of polyamide is also being foamed with a Nordson Foam Melter for a gasket in microwave ovens. 

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