SYNTHESIS OF POLYMERS CONTAINING PSEUDOHALIDE GROUPS BY CATIONIC POLYMERIZATION .2. POLYMERIZATION OF 2-METHYLPROPENE INITIATED BY THE SYSTEM DI(1-AZIDO-1-METHYLETHYL)-1,4-BENZENE TITANIUM TETRACHLORIDE

Within the context of functionalizing electrophilic chain polymerizati on of 2-methyl-propene (MP), the system di(1-azido-1-methylethyl)-1,4- benzene (DAMEB)/titanium tetrachloride leads to poly(2-methylpropene) bearing various terminal functions: tert-butyl, azide, tert-chlorine a nd unsaturations. Structures have been determined by H-1-NMR and FTIR. Their relative percentages can be modified by changing the experiment al conditions (temperature, solvent...). In the temperature range - 10 to - 70-degrees-C, an interdependence between the percentages of azid e and of unsaturations was found due to the excess of TiCl4 which can induce predominantly a dehydroazidation reaction. CH2Cl2 is found to b e a better solvent comparatively to hexane and CHCl3 for a specific az ide functionalization. A reaction of macromer dimerization was also de tected. With a molar ratio [TiCl4]/[DAMEB] equal to 6, a PMP azide fun ctionality of 1.7 was found, with a good agreement between the experim ental and theoretical average number molecular weight.