Effects of Structure on Properties

Crystallinity, crystal structure, morphology, and molecular orientation strongly affect the mechanical, thermal, electric, and hydrolysis resistance properties of PLA fibers. The 

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On the broad subject of thin films generally, a well-regarded early text is by an Indian physicist, Chopra (1969), while a very broad, didactic treatment of thin films in all their aspects is by Ohring (1992). A recent survey of the effect of structure on properties of thin films relevant to microelectronics is by Machlin (1998). 

Machlin, E.S. (1998) The Effects of Structure on Properties of Thin Films (GiRo Press, Croton-on-Hudson). 

Zlatanic, A. C. Lava W. Zhang Z.S. Petrovic. Effect of structure on properties of polyols and polyurethanes based on different vegetable oils./. Polym. Sci. Pol. Phys. 2004, 42, 809—816. 

Mishra, A., Sinha, T. M. J., and Choudhary, V. 1998. Methyl methacrylate-N-chlorophenyl maleimide copolymers Effect of structure on properties. /. Appl. Polym. Sci. 68 527-534. 

Effect of Structure on Properties of Absorbable Oxalate Pofymers... 

I.K. Varma, Veena, Effect of structure on properties of aromatic aliphatic polybenzimidazoles, J. Polym. Sci. Polym. Chem. Ed. 14 (4)(1976) 973-980. 

Tsu, Y., Levine, H.H., Levy, M. (1974) Effects of structure on properties of some new aromatic-aliphatic polybenzimidazoles. Journal of Polymer Science Part A Polymer Chemistry, 12, 1515-1529. 

This chapter sets the stage for all of the others by reminding us that the relationship between structure and properties is what chemistry is all about It begins with a review of Lewis structures moves to a discussion of the Arrhenius Brpnsted-Lowry and Lewis pictures of acids and bases and the effects of structure on acidity and basicity... 

Yous, B., Robin, S., Robin, J., and Donnadieu, A., Effects of Structure on the Optical Properties of Thin Films of Tungsten Compounds, Thin Solid Films, 130(3-7) 181-197 (Aug. 1985)... 

Monoparametric equation A relationship in which the effect of structure on a property is represented by a single generally composite parameter. Examples are the Hammett and Taft equations. 

Diparametric equation A relationship in which the effect of structure on a property is represented by two parameters, one of which is generally composite. Examples discussed in this work include the LD, CR and MYT equations. Other examples are the Taft, Ehrenson and Brownlee DSP (dual substituent parameter), Yukawa-Tsuno YT and the Swain, Unger, Rosenquist and Swain SURS equations. The DSP equation is a special case of the LDR equation with the intercept set equal to zero. It is inconvenient to use and has no advantages. The SURS equation uses composite parameters which are of poorer quality than... 

The subject of this chapter is carbenes with aryl substituents (aromatic carbenes). These materials are short-lived reactive intermediates in which the normal tetravalency of carbon is reduced by two. Carbenes have been the object of speculation and investigation for more than 80 years. Nevertheless, there still is considerable uncertainty about their chemical and physical properties. In the last five years the pace of research in carbene chemistry has quickened. This is a consequence of the development of high-speed pulsed lasers that permit, for the first time, direct observation of carbenes under the conditions in which they react. This research has provided new information on the effect of structure on the chemical and physical properties of carbenes. 

This report begins with a brief review of the electronic and structural features that underlie all of carbene chemistry. Next, we introduce the set of related aromatic carbenes that are the basis for our dissection of the effects of structure on carbene properties. The chemical and spectroscopic techniques and procedures used to probe these carbenes are described and explained briefly in the succeeding section. Then, the results of the application of these probes to the chosen carbenes are presented. Finally, the revealed relation of a carbene s structure to its chemical and physical properties is placed within the predictive framework of molecular orbital theory. Our objective in this report is to present sufficient information to permit us to forecast the properties of an aromatic carbene directly and reliably from its structure. 

When he interviewed with Meyer in 1926, Mark outlined a typically thorough program. He proposed a team of organic and physical chemists, and physicists who would evaluate the influence of structure on properties such as rigidity, elasticity, melting point, and water absorption. Work, he proposed, would shift toward new material development and into the manufacturing facilities to evaluate the effects of processing... 

Effects of Structure on the Properties of Polyoxyethylenated Nonionic Surfactants... 

The characteristics of particulate filled polymers are determined by the properties of their components, composition, structure and interactions [2]. These four factors are equally important and their effects are interconnected. The specific surface area of the filler, for example, determines the size of the contact surface between the filler and the polymer, thus the amount of the interphase formed. Surface energetics influence structure, and also the effect of composition on properties, as well as the mode of deformation. A relevant discussion of adhesion and interaction in particulate filled polymers cannot be carried out without defining the role of all factors which influence the properties of the composite and the interrelation among them. 

This subject has been of continuing interest for several reasons. First, the present concepts of the chemical constitution of such important biopolymers as cellulose, amylose, and chitin can be confirmed by their adequate chemical synthesis. Second, synthetic polysaccharides of defined structure can be used to study the action pattern of enzymes, the induction and reaction of antibodies, and the effect of structure on biological activity in the interaction of proteins, nucleic acids, and lipides with polyhydroxylic macromolecules. Third, it is anticipated that synthetic polysaccharides of known structure and molecular size will provide ideal systems for the correlation of chemical and physical properties with chemical constitution and macromolecular conformation. Finally, synthetic polysaccharides and their derivatives should furnish a large variety of potentially useful materials whose properties can be widely varied these substances may find new applications in biology, medicine, and industry. 

An extensive review of the synthesis of rc-conjugated polymers is presented using a tutorial approach to provide an introduction to the field intended for the undergraduate student and the experienced chemist alike. The many synthetic methodologies that have been used for the synthesis of conjugated polymers are outlined for each class of polymers with a focus on research from the 1990s. The effect of structure on electrical properties is detailed. Specific systems reviewed include the polyacetylenes, polyanilines, polypyrroles, polythiophenes, poly(arylene vinylenes), and polyphenylenes. 

Table 2. Effect of structure on the properties of aliphatic polyesters...

Systematic studies of the effects of structure on the biological activities of organic compounds and the analysis of the results are comprised in the term Quantitative Structure-Activity Relationships (QSAR). Many of the treatments employed in the correlation analysis of data in this field closely resemble those used for linear free-energy relationships, e.g. the Hammett equation and extensions thereof, and so the study of the biological properties of organic compounds is often regarded as a part of physical organic chemistry. In recent years, some historical study of work in... 

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