Crystals, and mechanical

It can be seen from Table I that these polymers varied both in their end block content and molecular weight. In the case of the BIB polymers, all the end blocks were of "high" molecular weight ( 50,000), while the BBB polymers contained both high and low ( 20,000) molecular weight end-blocks. The variation of these two parameters is important, as will be seen later in connection with crystallization and mechanical behavior of these materials. 

Figure 7.22. Mechanisms of ion incorporation into a calcite crystal and mechanisms of morphology control. In the Folk (1974) model (A), lattice distortion is induced by incorporation of the Mg2+ ion on the calcite edge face, whereas in the Lahann (1977) model (B), the mechanism of Ca2+ ion adsorption onto faces parallel and perpendicular to the calcite c-axis differs, resulting in differential charge development on crystal faces and morphologic variation. In (C) the postulated change in the habit of calcite with variation in the Mg2+ content of water is shown. (After Folk, 1974 Lahann, 1978.)...

In this chapter, we present results of the testing of a broad spectrum of polymers in carbon dioxide over a range of temperatures and pressures and evaluation of the effect of the high pressure carbon dioxide on the chemical/physical properties of materials tested. The testing was performed in a static manner with four controlled variables, namely temperature, pressure, treatment time and decompression time. The evaluation of the interaction of high pressure carbon dioxide with polymers included sorption and swelling behavior, solubility issue, plasticization and crystallization, and mechanical properties. The results of these evaluations are discussed in three sections Sorption, Swelling and Dissolution of Carbon Dioxide in Polymers at Elevated Pressure, Thermal Properties, and Mechanical Properties. ... 

The first resolution of trioxalatocobaltates was accomplished in 1916 with strychnine. The method of spontaneous crystallization of antipodes from a racemic mixture of a complex was first demonstrated with K3[Co(C204)s] above 13.2°, the optical antipodes may be crystallized and mechanically separated. In practice, however, the standard technique of fractional crystallization of the strychnine diastereoisomers has been used. Partial resolution on optically active quartz has also been reported. Selective decomposition of the antipodes by circularly polarized light... 

The worker unit is normally mounted with a heating jacket for tempered water on the cylinder and often also equipped with its own built-in water heater and circulation pump for the tempered water. This is advantageous in preventing product buildup on the cylinder wall and allows better product temperature control during the passage through the worker unit. Product temperature increases of 2°C or more due to release of latent heat of crystallization and mechanical work can be observed in the worker imit (3). 

We therefore attempted to couple the two nonhnear processes of crystallization and mechanical deformation in order to explain the unique morphology observed in the case of sPP single crystal. As expected, the solution of the coupled Equations 7.9 and 7.10 gives the oscillatory wave propagation leading to emergence of periodic... 

PLLA) - crystallization and mechanical property effects. Compos. Sci Technol, 70, 815-821. 

HDPE/bamboo composites with different nanoclay and maleated polyethylene (MAPE) contents were fabricated by melt compounding. The compounding characteristics, clay dispersion, HOPE crystallization, and mechanical properties of the composites were studied. The X-ray diffraction (XRD) data showed that the clay was exfoliated only when 1% clay was added to pure HOPE wifliout MAPE. For HDPE/bamboo systems, MAPE was necessary to achieve clay exfoUatiOTi. For the HDPE/bamboo fiber composites, tensile strength, bending modulus, and strength were improved with the use of MAPE however, the use of the clay in the system led to reduced mechanical properties [27]. 

Gao J, Zhang Q, Wang K, Fu Q, Chen Y, Chen H, Huang H, Rego JM (2012) Effect of shearing on the orientation, crystallization and mechanical properties of HDPE/attapulgite nanocomposites. Compos Part A Appl S 43 562-569... 

Table 2.14 The effect of storage time on crystallization and mechanical properties of Tencel fiber...

The following is the summary of the results of the studies (31) on the effect of stereoregularity on stress-induced crystallization and mechanical properties of the vulcanlzates of propylene oxide copolymers. In the studies on stress-induced crystallization, stress (O ) and birefringence ( ) were measured as a function of temperature using an Instron tester fitted with a thermostatted Insulated chamber and an optical system. In an amorphous rubber, the quantity (T Vo) (where T is absolute temperature) is almost constant. Stress-induced crystallization leads to the formation of crystals oriented in the stretching direction which substantially Increase the birefringence. 

Mason, W.P. (1964) Use of piezoelectric crystals and mechanical resonators in filters and oscillators, in Physical Acoustics, Vol lA (eds W.P. Mason and R.N. Thurston), Academic Press, New York. 

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