Indan-containing polymers

Ethyltoluene is manufactured by aluminum chloride-cataly2ed alkylation similar to that used for ethylbenzene production. All three isomers are formed. A typical analysis of the reactor effluent is shown in Table 9. After the unconverted toluene and light by-products are removed, the mixture of ethyltoluene isomers and polyethyltoluenes is fractionated to recover the meta and para isomers (bp 161.3 and 162.0°C, respectively) as the overhead product, which typically contains 0.2% or less ortho isomer (bp 165.1°C). This isomer separation is difficult but essential because (9-ethyltoluene undergoes ring closure to form indan and indene in the subsequent dehydrogenation process. These compounds are even more difficult to remove from vinyltoluene, and their presence in the monomer results in inferior polymers. The o-ethyltoluene and polyethyltoluenes are recovered and recycled to the reactor for isomerization and transalkylation to produce more ethyltoluenes. Fina uses a zeoHte-catalyzed vapor-phase alkylation process to produce ethyltoluenes. 

The GC/MS spectra were used to estimate the % depolymerization of TBMS under various conditions (see Table IV). The % depolymerization of polymer samples containing 2-nitrobenzyl tosylate is dependent upon the solvent used to cast films. When xylene is used, a higher % depolymerization is observed than with cyclohexanone. Moreover, the ratio of depolymerization products also varies with casting solvent. Specifically, the indan thermolysis product is more predominant when films were cast from xylene. The reaction with tosic acid hydrate resulted in a high degree of depolymerization this is most likely a consequence of depolymerization occurring during sample preparation. 

Fully imidized soluble polyimides have ben prepared using monomers derived from diphenylindane and aromatic dianhydrides. Technical polymers (XU218, for instance), prepared from 1,1,3-trimethyl-diaminophenylindane and benzophenone-tetracarboxylic acid dianhydride, have been marketed over the last decade. Despite the partially aliphatic nature of polyimides containing the indane group, they show considerable retention of the thermal stability, with Tg values over 300 °C [107-110]. 

Polyindanes have been obtained from a variety of monomers which are capable of forming benzyl carbenium ions stabilized with dialkyl groups upon the appropriate initiation. Linear polymers containing indane units in the main chain have been obtained by the BClj-initiated polymerization of 1,4-diisopropenylbenzene [Eq. (6)] [8]. Polyindanes with structural unit IS have also been obtained when difunctional monomers capable of forming a,a-dimethylbenzylic carbenium ions upon treatment with an initiator [8-12] (Fig. 4). 

These polymers contained indane structural units 49 and 52 (Fig. 9). This is because of the facile isomerization of 47 and 50 under the acidic reaction conditions. The relative proportion of 47 to 50 is determined by the equilibrium constant. Thus the two isomeric structural units are formed as a result of the electrophilic addition of 46 to 47 or to 50. 

Polyketones containing indane structural units have been prepared by Friedel-Crafts acylation [Eq. (12)] [17]. However, oligomers and/or insoluble polymers were obtained. 

Figure 2.31. U-v spectrum of absorption in CDA - films, containing 2% ofXX indan sulphuryl amide to polymer mass 1- CDA - film before irradiation 2-after 24 hours u-v - irradiation.

B. Dasgupta, S.K. Sen, S. Maji, S. Chatterjee, S. Banerjee, Synthesis and characterization of highly soluble poly(ether imide)s containing indane moieties in the main chain, J. Appl. Polym. Sci. 112 (6) (2009) 3640-3651. 

As shown in Tables EH and V, the permeability coefiBcients of the poly(ether ketone)s and the polyimides are comparable. Only polymer 9g, which contains the bulky, relatively rigid trimethylcyclohexyl linker in the bisphenol unit, exhibits significantly increased permeability coefficients relative to the other polymers in this study. Also, it is clear that the substantial increase in permeability coefficients that was initially expected from the introduction of the indan group, especially with the two cyclohexyl substituents, is not observed. Figures 1 and 2 show the common plots of loga vs. log P for the poly(ether ketone)s and the polyimides. 

Another process leading to soluble polymers utilizes divinyl monomers having phenyl group(s), e.g., p-diisopropenylbenzene (7) s,46) a,(o-bis(/ -isopropenyl-phenyl)alkanes" >. At high temperature, these monomers in conjunction with an MX initiator undergo, sequentially, protonation and intramolecular Friedel-Crafts alkylation (Eq. (10)) to form linear polymers containing indane units in the main chain ... 

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