Polymer Staudinger

Academic Publishers, 1989. Source for few academic chemists studied polymers Staudinger controversy available technology and Carothers high point of Faraday meeting. 

Hermann Staudinger Father of macromolecular chemistry, http //acswebcontent.acs. org/landmarks/ polymer/ staudinger.htm... 

Keywords Chirality Helix Macromolecules Mark Polymers Staudinger ... 

Until recently the question of how to classify all possible fypes of materials could not be answered because not all types of molecules had been recognized. The latest type of molecules discovered was the linear high polymer. Staudinger convinced the community of chemists in the early 1920s that molecules of strings of many thousands of atoms really exist. He suggested that molecules of more than 10,000 molecular mass, or with more than 1000 atoms be called macromolecules. With this definition of macromolecules one finally has a unique way of systematizing all materials. 

Besides POM, another polyether was intensively studied by Staudinger - poly (ethylene glycol) (PEG) - as an early example of an artificial high polymer . Staudinger and coworkers contributed key works both on the investigation of the synthesis of PEG from ethylene oxide as well as on its physicochemical properties (Table 1) [2-5]. Nowadays, this versatile polyether has become the gold standard polymer in drug delivery systems. It exhibits a unique combination of desirable properties rarely found for any other synthetic or natural polymer. PEG is nontoxic,... 

This relationship with a = 1 was first proposed by Staudinger, but in this more general form it is known as the Mark-Houwink equation. The constants k and a are called the Mark-Houwink coefficients for a system. The numerical values of these constants depend on both the nature of the polymer and the nature of the solvent, as well as the temperature. Extensive tabulations of k and a are available Table 9.2 shows a few examples. Note that the units of k are the same as those of [r ], and hence literature values of k can show the same diversity of units as C2, the polymer concentration. 

Polymers produced by methods as described above have thermal stabilities many times greater than those obtained by the earlier bulk and solution methods of Staudinger. Staudinger had, however, shown that the diacetates of low molecular weight polyoxymethylenes (I) (polyformaldehydes) were more stable than the simple polyoxymethylene glycols (II) (Figure 19.2). 

Staudinger also found that diacetates of polyoxymethylenes with a degree of polymerisation of about 50 were less stable. Truly high molecular weight polyoxymethylenes (degree of polymerisation -1000) were not esterified by Staudinger this was effected by the Du Pont research team and was found to improve the thermal stability of the polymer substantially. 

Furukawa, Y. (1998) Inventing Polymer Seience Staudinger, Carothers and the Emergence of Macromolecular Chemistry (Pennsylvania University Press, Philadelphia). 

Universal SEC calibration reflects differences in the excluded volume of polymer molecules with identical molecular weight caused by varying coil conformation, coil geometry, and interactive propenies. Intrinsic viscosity, in the notation of Staudinger/ Mark/Houwink power law ([77]=fC.M ), summarizes these phenom-... 

Furukawa, Y. Inventing Polymer Science Staudinger, Carothers, and the Emergence of Macromalecular Chemistry University of Pennsylvania Press Philadelphia 1998. 

Staudinger concept of polymer structure 1-2 stereoelectronic effects... 

The molozonide was unstable and would either rearrange into the isozonide or form polymers. While Staudinger s theory explained the formation of the major products, some of the by-products could not be accounted for. The greatest step toward complete elucidation of the ozonolysis reaction was made by Criegee (Ref 3) In the 1950s. From a study of ozonolysis in various solvents and the constitution of the products, Criegee proposed these reactions ... 

Low Conversion Reactors. The major problem in temperature control in low conversion reactors is the orders cf magnitude increase in viscosity as the conversion increases. Fig.8 shows the viscosity of a polystyrene solution as the function of percent PS. The data are for polystyrene with a Staudinger molecular weight of 60,000 at 100 C and 150 C in a cumene solution, a satisfactory analog for styrene monomer solutions. As the polymer concentration increases from 0 to 60%, viscosity increases from about 1 cp to 10 cp. 

The polymer in natural rubber consists almost entirely of ci -poly(isoprene) (1.6). The molecules are linear, with relative molar mass typically lying between 300 000 and 500 000. The macromolecular nature of rubber was established mainly by Staudinger in 1922, when he hydrogenated the material and obtained a product that retained its colloidal character, rather than yielding fragments of low relative molar mass. 

Tyndall s effeet Physieal properties of polymers Swelling of stareh and SAP Theory of polymers by Staudinger... 

Fig. 10.5 Theories about the eonstitution of polymer materials . Left the theory of mieells by Mark and Meyer (1928) at the example of eellulose, right Herrmann Staudinger with a model of a polymer ehain...

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