Poly with different halogen

During photolysis, the double bond content of the polysilane(P-l)(15mol% in this experiment) decreased to 10mol%, as measured by 1H-NMR spectroscopy. However, the ratio, quantum yield of scission(Q(S))/quantum yield of crosslinking(Q(X)), was not affected by the reaction of the double bond. West and his coworkers have reported that poly((2-(3-cyclohexenyl)-ethyl)methylsilane-co-methylphenylsilane) crosslinked upon irradiation(55). The difference between our results and West s may lie in the amount of the double bond and inhibitation of the radical closslinking by the phenol moiety. Polysilane with a halogen moiety, P-8, photodecomposed rapidly, compared with P-1 or P-3. The introduction of a chloride moiety was effective for the sensitization of the photodegradation. Similar results has already been reported(55). 

In such cases, with the halogen and hydroxyl linked to different carbon atoms, stable compounds result. As direct action of halogens oxidizes the alcohol to aldehyde or ketone, this new kind of halogen-alcohol must be prepared by a different reaction. When poly-hydroxy alcohols react with halogen acids, e.g.j hydrochloric acid, HCI, or with phos-... 

In this chapter, the new thermotropic liquid crystal poly(azomethine esters) were designed and synthesized as T-shaped azomethine bisphenols containing azomethine linkage (-CH=N) attached to different halogens and were reacted with terephthaloyl chloride that has been obtained from the regenerated terephthalic acid of PET waste bottles. The effect of the azomethine linkages and the type of the substituents (halogens) on the liquid crystalline behavior, thermal stability, as well as the crystalline states of these polymers were further studied and analyzed. 

The additivity treatment also allows one to evaluate the influence of substituents which are otherwise obtainable only with difficulty. The study of the non-catalytic bromination of the halo-substituted poly-methylbenzenes by Illuminati and Marino (1956) allowed the evaluation of the partial rate factors for the highly deactivating m- and p-halogens. These data for the slow, highly selective bromination are inaccessible by other techniques. Analysis of the relative rates is made by application of the additivity equations (5) and (6) as described in Section I. An important aspect of the chemistry of the substituted polymethyl-benzenes, in contrast to the monosubstituted benzenes, is the large difference in p for bromination. The partial rate factors derived for each reaction are correlated with good precision by the tr4 -constants (Figs. 11 and 19). Yet the susceptibility of the reactions to the influence of substituents is altered by more than 25%. As already noted, this aspect of the problem is not well defined and is worthy of additional attention. 

The addition of elemental halogen or hydrogen halides to C-C multiple bonds is the most important halogenation reaction in industrial chemistry. At present, 1,2-dichloroethane (DCE, by chlorination of ethylene) is among those chemicals with the highest production rates and is now used as a starting material for the production of poly (vinyl chloride) (PVC, Scheme 2) [6], Vinyl chloride monomer (VCM) can be achieved by three different routes. 

The halogen end group can be transformed into other functionalities by means of standard organic procedures, such as a nucleophilic displacement reaction. Different authors have investigated this process of the nucleophilic displacement reactions with model compounds, to confirm the feasibility and selectivity. Compounds such as 1-phenylethyl halide, methyl 2-bromopropionate, and ethyl 2-bromoisobutane mimic the end groups of PSs, poly(alkyl acrylates), and poly(alkyl methacrylates), respectively. Different compounds have been tested, such as sodium azide, n-butylamine, and n-butylphosphine. 

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