SYNTHESIS OF POLYMERS CONTAINING PSEUDOHALIDE GROUPS BY CATIONIC POLYMERIZATION .14. FUNCTIONALIZING LIVING POLYMERIZATION OF 2-METHYLPROPENE INITIATED BY THE SYSTEM 1,4-BIS(1-AZIDO-1-METHYLETHYL)BENZENE DIETHYLALUMINUM CHLORIDE

The polymerizations of 2-methylpropene (MP) via ''all monomer in'' (AM I) and ''incremental monomer addition'' (IMA) techniques initiated by the system 1,4-bis(1-azido-1-methylethyl)benzene (DAMEB)/AlEt(2)Cl/CH2 Cl2 behave like a functionalizing ''living'' system in the range of (M ) over bar(n) < 50 000 without the assistance of an electron donor. Th is is demonstrated by the azide F-N3, and aromatic ring F-Phi function alities close to the theoretical values of 2 and of 1, respectively, f or a specific functionalization; by the linearity of the (M) over bar( n) versus weight of polymers (W-p) plot without intercept, and by the constant chain number N close to the theoretical N-0. It is also shown that a poly(2-methylpropene) alpha,omega-diazide (PMP) used in combin ation with AlEt(2)Cl is able to reinitiate the polymerization of MP. T he final polymer presents the same functionalities F-N3 and F-Phi as t he starting polymer used as initiator, and the increase of (M) over ba r n corresponds to the amount of MP introduced. The monomodal SEC chro matograms of the starting and of the final PMP show that the whole azi de chain ends are efficient in this experiment of reinitiation of poly merization from the functionalized PMP. The Mayo 1/<(DP)over bar> vers us 1/<(DP)over bar>(0) plot gives a straight line, the intercept of wh ich corresponds to the ratio k(trM)/k(p) 2 X 10(-5), indicating that a possible transfer reaction to monomer could proceed at a very low rat e, only detectable in the range of high (M) over bar(n) > 50 000.