Poly propene

Like poly(ethylene), there are formal problems with the nomenclature of this polymer, since its lUPAC name, poly(propene), is also rarely if ever used hy polymer chemists. Since, in practice, no ambiguity is associated with the non-systematic name, this is the one that is generally used, as it will he throughout this hook. 

Poly(propene) Ropes, carpets, clothing, pipes, crates... 

Research Focus Method for preparing poly(propene-l-butene-l-hexene) using a silyl/ zirconium-based Ziegler-Natta procatalyst. 

Figure 29-8 Configuration of atactic, isotactic, and syndiotactic poly-propene. These configurations are drawn here to show the stereochemical relationships of the substituent groups and are not meant to represent necessarily the stable conformations of the polymer chains.

Other alkene molecules can also produce substances like poly(ethene) for example, propene produces poly(propene), which is used to make ropes and packaging. 

Poly(propene) ch3ch = ch2 Tough, durable Ropes, packaging... 

Using highly stereoselective metallocenes, highly crystalline, stiff poly-propene types are produced. These polymers exhibit a stiffness 25-30% above that of conventional polypropenes, resembling that of polypropenes filled with... 

Table 15. Mechanical properties of highly stiff poly propenes compared to normal materials [154]...

Iodine readily reacts with polymers bound to coordination centres, yielding macromolecules containing iodide end groups. The C—I bond can react with silver salts of superacids yielding carbocations essentially in the sense of the last steps of eqn. (32). Doi et al. [251, 252] have used this reaction for the synthesis of the copolymer poly(propene)-Mocfc-poly(tetramethylene oxide) with blocks of syndiotactic polypropylene. 

Vanadium-containing coordination centres producing syndiotactic polypropylene at 195 K can be transformed to radical centres simply by raising the temperature to 298 K [252]. In this way, Japanese authors have prepared the copolymer poly(propene)-Wocfc-poly(methylmethacrylate). The radical end is probably formed by homolytic splitting of the C—V bond, and it can be stabilized by the V ion. The authors state that, in this way, two-component blocks of polypropylene with various polymers propagating by the radical mechanism can be prepared. 

Ph3SbBr2 has been evaluated as a fire retardant in poly(propene). The radicals formed on its thermolysis are the quenching agents for the radicals formed in the pyrolysis of the polypropylene. 

The coefficients 8.10 and 0.010 in the second equation are usually ascribed to the reactivity ratios rj and rj (Table 19). This catalyst produces poly-propene consisting mainly of syndiotactic stereoblocks, together with short disordered blocks resulting from head-to-head (hh) and tail-to-tail (tt) pro-pene enchainment and occasional isolated isotactic units, and if these features apply to copolymers prepared with vanadium catalysts, the reaction is in effect a terpolymerization. Locatelli et al. [322] derive the equation for monomer/polymer composition ratios... 

The nitric acid solution from the dissolution of the fuel rod contents is filtered [poly(propene) fleece] or centrifuged, to remove suspended solids (zirconium- or molydenum- compounds and ruthenium and palladium alloys). The thus obtained fuel solution contains uranium, plutonium and the radioactive fission products. It is, after its composition is adjusted to the extraction conditions (3 molar in nitric acid and 240 to 300 g/L uranium) subjected to multi-cyclic extraction with tributylphosphate (dissolved in dodecane). Uranium and plutonium pass into the organic phase and are thereby separated from the fission products, which remain in the aqueous phase. 

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