Effect of temperature on orientation

How do you account for this effect of temperature on orientation Suggest a role for the HCl. 

Despite the extreme importance of the thermal properties on the processing and performance of textile polymers, particularly in filament processing and finishing, there are surprisingly few standard methods of test dealing with the subject. This is perhaps due to the complexity of the subject in terms of the effects of temperature on oriented chain molecules and influence of moisture on the polymer. However, a standard method that is available is ASTM D 5591-95, which is concerned with the thermal shrinkage force of yarn and cord. The instrument specified is the Testrite thermal shrinkage force tester... 

Thus, two interpretations based on two different concepts of the effect of temperature on dipole orientation have been put forward. The two views clash with each other on physical as well as chemical grounds. However, the view based on the correlation of Fig. 25 introduces chemical concepts that are absent in the other, which ignores some definite facts. For instance, although a value for dEa=0/dT is not available for Ga, the temperature coefficient of C is apparently small.905 Ga is universally recognized as a strongly hydrophilic metal. Therefore, according to the simple model of up-and-down dipoles, the effect of temperature should be major, which is in fact not the case. 

B. Amram, L. Bokobza, P. Sergot, and L. Monnerie, Effect of temperature on intermolecular orientational correlations between chain segments in strained poly-isoprene A Fourier transform infrared dichroism investigation, Macromolecules, 23, 1212 (1990). 

Morscher and Sayir (1995) studied the effect of temperature on the bend radius that a c-axis-oriented sapphire fiber can withstand for fibers of various diameters. They did this by performing bend stress rupture tests on these fibers... 

IV. The effect of temperature on all the different possible intramolecular motions can only be determined quantitatively to a trifling extent. Hence in what follows we can only select a few important considerations for discussion these chiefly relate to the question whether internal motions are capable of giving rise at high temperatures to a genuine orientation term in the case of molecules which at low temperatures are non-polar. 

Fig. 11. Effects of temperature on water solubility (in negative logarithmic units, moles/l) of undissociated free bile acids at pH 3. (Modified from ref. 90.) Numbers and Greek letters denote position and orientation, respectively, of hydroxyl groups in each 5/3-cholanoic acid. Mean m.p.s [34-41, and private communications from A. Roda and A.F. Hofmann] are indicated on each curve.

These authors found a pronounced effect of temperature on the orientation of the spun fibers. Increasing the spinning temperature with other variables unchanged resulted in a lower orientation. 

The mold temperature, on the other hand, affects the thickness of skin layers [82,83,87]. In general, the effect of temperature on the mechanical properties is relatively small compared to the injection speed. Mathematical modeling and computer simulations based on Doi s molecular theory for the motion of rigid rods were recently used in an attempt to predict the orientation and flow behavior of TLCPs in the mold as a function of processing conditions. A reasonably good agreement between the simulation and the experiment was reported [88]. 

He L X and Tjong S C (2010) Effect of temperature on electrical conduction behavior of polyvinyl-idene fluoride nanocomposites with carbon nanotubes and nanofibers, Curr Nanosci 6 520-524. Bhattacharyya A R, Sreekumar T V, Liu T, Kumar S, Ericson L M, Hauge H and Smalley R E (2003) Crystallization and orientation in polypropylene/single wall carbon nanotube composite. Polymer 44 2373-2377. 

Figure 6.3. (a) Knoop hardness values for single-crystal SiC as a function of indenter long-axis orientation. At 0° the long axis is parallel to <1120) at 60°, to <1120) and at 30°, to <10T0). (b) Vickers hardness of CVD SiC as a function of deposition temperature, (c) Effect of temperature on Vickers hardness of CVD layer deposited at 1000°C for 24 hours. 

Kwon YK, Chvalun S, Blackwell J, Percec V, Heck JA (1995) Effect of temperature on the supramolecular tubular stmcture in oriented fibers of a poly(methacrylate) with tapered side groups. Macromolecules 28(5) 1552-1558. doi 10.1021/ma00109a029... 

The effect of temperature on the microstructures and dominant slip systems determined from textures are similar for both experimentally and naturally deformed quartzites (see [266-269]). Inferences about shp systems from textures are not unequivocal, especially because many texture studies rely only on c-axis orientations and not the full orientation distribution. There are very few TEM investigations identifying dislocation geometries in natural quartzites. The newer studies are consistent with the concept that (0001) j[2 11 0] slip dominates at lower temperatures, with a transition to 1010 112 0) slip at intermediate temperatures ( 900°C in the laboratory, 500-600°C in the Earth) and finally 1010 [0001] slip at temperatures above 600-700°C in the Earth [267]. Shp on the rhombohedral planes in a and c directions is also observed. The different transition temperatures observed for experiments and rocks recovered from natural settings are interpreted to reflect a kinetic trade-off between the temperature and strain rate. Experimental samples creep at rates 10 -10 times faster than deformation occurs in the Earth. 

The heat of decomposition (238.4 kJ/mol, 3.92 kJ/g) has been calculated to give an adiabatic product temperature of 2150°C accompanied by a 24-fold pressure increase in a closed vessel [9], Dining research into the Friedel-Crafts acylation reaction of aromatic compounds (components unspecified) in nitrobenzene as solvent, it was decided to use nitromethane in place of nitrobenzene because of the lower toxicity of the former. However, because of the lower boiling point of nitromethane (101°C, against 210°C for nitrobenzene), the reactions were run in an autoclave so that the same maximum reaction temperature of 155°C could be used, but at a maximum pressure of 10 bar. The reaction mixture was heated to 150°C and maintained there for 10 minutes, when a rapidly accelerating increase in temperature was noticed, and at 160°C the lid of the autoclave was blown off as decomposition accelerated to explosion [10], Impurities present in the commercial solvent are listed, and a recommended purification procedure is described [11]. The thermal decomposition of nitromethane under supercritical conditions has been studied [12], The effects of very high pressure and of temperature on the physical properties, chemical reactivity and thermal decomposition of nitromethane have been studied, and a mechanism for the bimolecular decomposition (to ammonium formate and water) identified [13], Solid nitromethane apparently has different susceptibility to detonation according to the orientation of the crystal, a theoretical model is advanced [14], Nitromethane actually finds employment as an explosive [15],... 

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