Influence of chemical structure on the

Ashby, J., and D. Paton (1993). The Influence of Chemical Structure on the Extent and Sites of Carcinogenesis for 522 Rodent Carcinogens and 55 Different Human Carcinogen Estytosurts."Mutation Research 286, 3-74. 

Ashby, J. and Paton, D. (1993) The influence of chemical structure on the extent and sites of carcinogenesis for 522 rodent carcinogens and 55 different human carcinogen exposures. Mutat. Res., 286, 3-74. 

As in all thermosetting polyimides, the diamine and the tetracarboxylic dianhydride employed to build the backbone can be varied. Alteration of the diamine, tetraacid or both, allow the modification of the polyimide s melting point and solubility. Of interest to the end user is the influence of chemical structure on the melting transition of the prepolymer and the Tg of the fully cured product. Lowering the uncured Tg means increasing flow and, in most... 

In order to investigate the influence of chemical structure on the melt viscosity, polyesters A1.A2.B1 and B2 were compared in the steady mode in plate and plate-geometry at 300°C. A2 and B2 should be in the isotropic region, whereas Al, B1 would be in the nematic state. Prior to steady shear measurements a transient step from... 

FIGURE 3.19 VI as a function of CMRP content for group II and in base stocks. Source V. J. Gatto M. A. Grina, T. L. Tat, H. T. Ryan. The Influence of Chemical Structure on the Physical and Performance Properties of Hydrocracked Basestocks and Polyalphole-fins, Journal of Synthetic Lubrication 19 13-18 (2002). With permission. 

The compound on the left is solid at room temperature (melting point of 137.5 C). The compound on the right is liquid (melting point -30°C). This shows the main direction of influence of chemical structure on the properties of the plasticizer. 

INFLUENCE OF CHEMICAL STRUCTURE ON THE (DE)VITRIFICATION BEHAVIOUR OF THE THERMOSETTING SYSTEMS... 

Park, J., Eslick, J., Ye, Q., Misra, A., Spencer, R The influence of chemical structure on the properties in methacrylate-based dentin adhesives. Dent. Mater. 27,1086—1093 (2011)... 

Influence of chemical structure on the physical properties of chemicals and fibers... 

The medicinal chemist expects to find that a review written specifically for him will he mainly concerned with a discussion of structure/activity relationships. In the case of the antihypertensive activity of the (3-blockers such a discussion is not possible since no direct comparative activity data is available either from the laboratory or the clinic (the few comparative clinical studies are in no way definitive - see later). It is however possible to approach the problem somewhat indirectly and consider the influence of chemical structure on those pharma -cological properties which appear most relevant to the specific clinical effect. I propose therefore to -... 

Two pattern recognition techniques are applied to the analysis of the library of FTIR spectra compiled by the US EFA> The patterns which emerge demonstrate the influence of molecular structure on the spectra in a way familiar to chemical spectroscopists They are also useful in evaluation of the library, which is not error free, and in assessing the difficulties to be expected when using FTIR spectra for complex mixture analysis. 

The results of studies on the influence of molecular mass and molecular mass distribution of PIB on the kinetics of its thermal degradation are of interest because of the effect of chemical structure on the thermal stability of the polymer. Several high and low molecular mass fractions and non-fractionated samples of PIB with high and low molecular masses have been used in these studies. It has been found that the molecular mass of PIB sharply decreases from about two million to about 25,000 in the initial period (10% of weight loss) of polymer degradation under vacuum at 300 °C. Thereafter the decrease in molecular mass of the polymer decelerates. 

As the form factor analysis provides detailed insight into the particle structure, one can use this information in order to adapt the polymerization conditions, as, for example, batch, semibatch synthesis, or controlled monomer feed, in order to tailor particle morphology and thus microgel properties.In addition, one can employ SANS data to investigate the influence of chemical reactivity on the microstructure by comparing, for example, different cross-linkers, initiators, or monomers. 

There are very few reports on biodegradation of MTBE. MTBE is a very persistent chemical (Yeh and Novak, 1994). All indications are that it will biodegrade slowly in suitably acclimated conditions. Suflita and Mormile (1993) have found that oxygenates containing a tertiary or quaternary carbon atom were much more recalcitrant than their unbranched or not so hindered counterparts. The strong influence of chemical structure on biodegradation has been known for decades. For example, K-butyl methyl ether has been shown to degrade at a faster rate than MTBE under similar suitably acclimatized systems. 

Lin C-H, Dimitrov DZ, Du C-H, Lan C-W (2010) Influence of surface structure on the performance of black-silicon solar cell. Phys Stat Solid C7(ll-12) 2778-2784 Lin T-C, Shiu S-C, Pun K-L, Syu H-J, Lin C-F (2012) Layer transfer of crystalline Si thin film by metal-assisted chemical etching concerning different H2O2/HF ratios. In 38th IEEE Photovoltaic Specialists Conference (PVSC), Austin (USA), pp 000346-000349 Lipinski M (2008) Macroporous texturing of multicrystalline silicon for solar cells. Arch Metall Mater 53(1) 185-187... 

Only small differences in chemical structure of molecules can result in a high increase in reactivity and therefore in an enhanced toxicity. The most striking examples of influences of chemical structure on reactivity and toxicity are found for compounds like 3-chlorotoluene and a-chlorotoluene. Although the structu res of these two compounds are very close at first sight, a-chlorotoluene is reactive while the other compound is unreactive in the NBP test. The higher reactivity of a-chlorotoluene is caused by resonance effects. The possibility of resonance structures for a-chlorotoluene yields a more stable intermediate carbonium ion. 

Harrison, W., Wang, F., Mecham, J., Glass, T., Hickner, M., McGrath, J. (2001) Influence of bisphenol structure on the direct synthesis of sulfonated poly(arylene ether)s. In Abstracts of Papers of the American Chemical Society, Vol. 221, American Chemical Society, Washington, DC, p. U415. 

NG Zaripov, RR Kabtrov, VN Bloshenko. Structural peculiarities of cermets design based on titanium carbide. Part 1. Influence of chemical composition on the ductile-brittle transition temperature, microstructure and properties of cermets. J Mater Sci 31 5227, 1996. 

This text is intended primarily for design engineers and engineering students. However, the first chapter contains some chemistry, but only what is necessary to acquaint the student with the background necessary to understand the significant influence of chemical structure on mechanical properties of polymers. 

Lunn, G. A. 1982b. The Influence of Chemical Structure and Combustion Reactions on the Maximum Experimental Safe Gap of Industrial Gases and Liquids./. Hazardous Materials, 6, 341-359. 

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