Epoxide polymers structure

Epoxide polymers exhibit stereoisomerism originating from the chirality of tertiary carbon atoms present in the polymer main chain. The stereoisomers of epoxide polymers are therefore tactic polymers their tacticity is connected with the structure of epoxide monomers undergoing polymerisation. Epoxide... 

Figure 9.1 Structure of epoxide polymers of various tacticity obtained from mono- and disubstituted epoxides...

Ethylene chlorohydrin is made from HCl and ethylene epoxide. When small amounts of 1,2,3-trichloropropane are added to the bis(2-chloroethyl)formal, some branching of the otherwise linear polymer structure is achieved. 

The physical and mechanical properties of polyanhydrides can be altered by modification of the polymer structure with a minor change in the polymer composition. Several such modifications include the formation of polymer blends, branched and crosslinked polymers, partial hydrogenation and reaction with epoxides. 

Vandenberg, E.J., 1969. Epoxide polymers synthesis stereochemistry structure and mechanism. J. Polym. Sci. Part A Polym. Chem. 7 (2), 525-567. 

Thus, for block copolymers based on dimethylsiloxane with dkylene glycols as surface-active additives there is a relation between the structure of the epoxide system in the liquid state and that in the hardened state. This dlows regulation of the properties of polyepoxides using the thermodynamic characteristic of these surfactant solutions in monofunction d epoxide compounds. In addition, it is found that the introduction of surfactants of the epoxide series to polyepoxides affects the p u lmeters of the polymer structure rather differently, depending on the uTangement (parallel or perpendicular) of lyophobic groups of KEP-2 in a monolayer with respect to the interface. 

Vandenberg, E. J. Epoxide polymers Synthesis, stereochemistry, structure, and mechanism. J. Poly. Sci., Poly. Chem. Ed. 1969, 7, 525-567. 

In the other route, polymerised cardanol was prepared from cardanol and H202in the presence of peroxidase and, subsequently, the epoxide-containing polycardanol was synthesised from polycardanol, H202and an organic acid in the presence of lipase. NMR and IR spectroscopy confirmed the polymer structure the former route yielded epoxide-containing polycardanol in a higher yield of over 90%. 

The model is applied to styrene-butadiene-styrene block copolymers, pol3mrethanes, and nitrile-modified epoxide polymers. Kaelble discusses the particular advantages of block copol3nners as elastomeric and structural adhesives. 

TABLE 8 Range of Polymer Structure/Properties Through Stereo-Control of Epoxide Polymerization... 

Draw structures to show how addition of the triamine results in strengthening the polymer. Amines are good nucleophiles and can open epoxide rings in the same way other bases can. 

Chen, Y., Puskas, J.E., and Tomkins, M. Investigation of the effect of epoxide structure on the initiation efficiency in isobutylene pol3mierizations initiated by epoxide/TiCLt systems, Eur. Polym. J., 39, 2147-2153, 2003. 

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