Orientational process

Introduction Fundamental Aspects of Orientational Processes in Crystallizable... 

These two different approaches for attaining an oriented state in flexible-chain and rigid-chain polymers indicate that the fundamental property of macromolecules - their flexibility - is of great importance to the orientation processes. However, the mechanism of the transition into the oriented state and the properties of highly oriented systems exhibit many features characteristic of both rigid- and flexible-chain polymers. 

Usually, the transition of polymer systems into the oriented state occurs as a result of deformation e.g. upon exposure to external stress. When the polymers undergo deformation both the macromolecule as a whole and its parts (segments) can undergo orientation. The rates of these orientation processes are very different and, hence, the orienting forces affect first of all the orientation of chain segments and subsequently that of a chain molecule as a whole. However, by varying the extension velocity and the temperature, only the overall orientation process may predominate, thus extension of all chains occurs in a single act. 

Polymer Flexibility as a Decisive Parameter of the Thermodynamic and Kinetic Features of Orientation Processes... 

Hence, the main aim of the technological process in obtaining fibres from flexible-chain polymers is to extend flexible-chain molecules and to fix their oriented state by subsequent crystallization. The filaments obtained by this method exhibit a fibrillar structure and high tenacity, because the structure of the filament is similar to that of fibres prepared from rigid-chain polymers (for a detailed thermodynamic treatment of orientation processes in polymer solutions and the thermokinetic analysis of jet-fibre transition in longitudinal solution flow see monograph3. ... 

Preece, P. E., Kift, M. H. and Grills, D. M. (1991) Computer-Orientated Process Design, Proceedings of COPE, Barcelona, Spain, Oct. 14-16, 209, A graphical user interface for computer aided process design. 

The SD is a phase separation process usually occurring in systems consisting of more than two components such as in solutions or blends. However, in the present case the system employed is composed of one component of pure PET. In this case, what triggers such an SD type phase separation Doi et al. [24, 25] proposed a dynamic theory for the isotropic-nematic phase transition for liquid crystalline polymers in which they showed that the orientation process... 

Wibowo, C. and Ng, K.M., 2001 Product oriented process synthesis and development creams and pastes, AIChE Journal, 47,2746 - 2767... 

C. Wibowo K.M. Ng, 2001, Product-Oriented process synthesis and development Creams and pastes, AIChE J., 47(12), 2746... 

End-use applications for naphthalate-based polyester resins depend on optimizing the balance of properties desired in a specific application. Usually this involves optimizing the orientation process (uni- or bi-axial) with its accompanying crystallinity development. Subsequent heat setting may be included when additional improvements in thermal stability are needed. 

The amorphous PEN resin pellets are first dried at 180 °C and then extruded at 290-300 °C through a die, formed into a sheet, which is then followed by a two-step orientation (forward draw and sideway draw process) just above the glass transition temperature (Tg) (>120°C). After the orientation process, the PEN film is conveyed between rollers at 210-220 °C to induce crystallization. At the end of the orientation and crystallization process, the film is cut and rolled into widths and lengths to suit individual customers [14-16], Two of the process used to produce such films are shown in Figure 10.3. 

It should be noted that the dynamics studied by fluorescence methods is the dynamics of relaxation and fluctuations of the electric field. Dipole-orientational processes may be directly related to biological functions of proteins, in particular, charge transfer in biocatalysis and ionic transport. One may postulate that, irrespective of the origin of the charge balance disturbance, the protein molecule responds to these changes in the same way, in accordance with its dynamic properties. If the dynamics of dipolar and charged groups in proteins does play an important role in protein functions, then fluorescence spectroscopy will afford ample opportunities for its direct study. 

Since our solvents are permanent dipoles that develop an orientation under the influence of an outside electric field activity in opposition to the disordering influence of thermal agitation, such an orientation process is governed by the Boltzmann distribution law and results in the dielectric constant being strongly dependent on the absolute temperature. Thus, as the systems become cooler, the random motion of their molecules decreases and the electric field becomes very effective in orienting them the dielectric constant increases markedly with reduction in temperature at constant volume. 

Include the knowledge from the lessons learned in training, orientation, process safety information, and written procedures for employees. 

Mechanical properties of polymers are improved by orientation processes [22, 24, 29]. Because of the biaxial orientation, films from blown film lines exhibit, e.g., a high puncture and tear propagation resistance. Blown film lines can be designed to produce flexible PE-LD or PE-HD films of 5-200 pm. 

Compare and contrast the important features of a pharmaceutical and food orientated process. Do the very different markets for the products made affect the type of technology used ... 

FIGURE 5 Object-oriented process modeling method (CIMpgr) as applicable to pharmaceutical manufacturing/assembly/packaging system design. 

Organic azides combine with open-chain and cyclic eno) ethers to give A -triazolines in high yield. The addition is stereospecific cis and the orientation process is determined by electronic effects.145-160 The triazolines are unstable above 100° and can decompose in mainly two ways. 44 Triazolines from the open-chain enol ethers, vinyl butyl ether, /S-ethoxypropene, and a- and /3-methoxystyrene, eliminate alcohol thermally and are converted into 1,2,3-triazoles. For example, the triazoline 67 from /J-ethoxypropene 66 and p-nitrophenyl azide decomposes quantitatively at 150° into l-(p-nitrophenyl)-5-methyl-1,2,3-triazole (68). 

Organic azides combine with open-chain and cyclic enol ethers to give AMriazolines in high yield. The addition is stereospecific cis and the orientation process is determined by electronic effects.196 266 The triazolines are unstable above 100° and can decompose in mainly two ways.260... 

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