| Polyisobutylene (PIB) with arylamino-terminal group had been synthesized by combination of controlled cationic polymerization with Friedel-Crafts alkylation. The research work included the H2O-initiated controlled cationic polymerization of isobutylene (IB) to prepare terminal-reactive polyisobutylene (TRPIB) with tert-chloro or/and a-double bond groups, the controlled alkylation of triphenylamine (TPA) or diphenylamine (DPA) with TRPIB, and the combination of controlled cationic polymerization with successive alkylation in One-pot were carried out respectively.1. The controlled cationic polymerization of IB to prepare TRPIBThe cationic polymerizations of IB with2,4,4-trimethyl-1-pentyl chloride (TMPCl) or H2O as monofunctional initiator, and1,4-dicumyl chloride (DCC) as bifunctional initiator respectively in conjunction with TiCl4were carried out in the presence of electron pair donors (ED) such as N,N-dimetylacetamide (DMA) and TPA or proton trap such as2,6-di-tert-butyl-pyridine (DtBP).<1> Found that the initiation competition existed between DCC and H2O in the cationic polymerization of IB even though in the presence of excess DCC ([DCC]/[H2O]=33.5) and DfBP ([D/BP]/[H2O]=1.25),in which89%of Cl-PIB-Cl induced by DCC and11%of PIB-Cl by H2O respectively.<2> Interestingly, the controlled cationic polymerization of IB with H2O/TiCl4initiating system was achieved in the presence of DMA even at relatively high [H2O]([H2O]=3.25×10’3～6.51×10-3mol·L-1) and high temperature (Tp=-30～-40℃). DMA played an important role in the polymerization. Enough DMA ([DMA]/[H2O]=4.8～8.7) could be needed to increase initiation efficiency, stabilize growing active species and suppress chain transfer reaction. Monomer conversion decreased with increasing [DMA] and the kinetic order of DMA was determined to be-0.12and-0.81when [DMA]/[H2O]≤4.6and [DMA]/[H2O]≥4.6, respectively. The PIBs with tert-Cl of more than95%, Mn of2400～11000g-mol-1and Mw/Mn of around1.7were obtained at [TiCl4]/[H2O] of30-46. The activity energy of propagation at-40℃were further determined to be-16.4kJ-mol-1.<3> Found that TPA played dual roles in H2O/TiCl4initiating system at-40℃:<a> to modulate the polymerization the similar that of DMA;<b> to react with growing PIB chain end. The content of PIB-TPA increased with increasing [TPA] and decreasing [TiCl4], and it could reach39%at [TPA]=9.2×10-4mol·L-1and [TiCl4]=0.15mol·L-1.2. The controlled alkylation of arylamine derivates with TRPIBThe alkylation of TPA or DPA with TRPIB, such as PIB-Cl, Cl-PIB-Cl and/or a-double bond terminated PIB (αDBPIB) catalyzed by TiCl4were carried out under various conditions. The corresponding experimental results were indicated as follows.<1> Mono-, di-and tri-alkylation of TPA with TRPIB could be achieved. Alkylation efficiency (Aeff) increased with increasing [TPA],[TiCl4],[TRPIB] and alkylation time (ta) while Alkylation degree (Ad) increased with decreasing [TPA]. Aeff and Ad were independent of MW of PIB-C1with Mn=2400～10500g.mol-1and PIB-TPA-PIB with Aeff.N of66%could be obtained.<2> The controlled alkylation of TPA with aDBPIB could be achieved under appropriate conditions:<a> PIB-TPA with Aeff.N of95%could be synthesized at [TiCl4]/[αDBPIB]=20and [TPA]/[aDBPIB]=5;<b> PIB-TPA-PIB with Aeff.N of98%was obtained at [TiCl4]/[αDBPIB]=80and [TPA]/[aDBPIB]=2;<c> triarm (PIB-)3TPA with Aeff.N of more than85%were achieved at [TiCl4]/[αDBPIB]=80-100and [TPA]/[αDBPIB]=0.6.<3> The alkylation of DPA by TRPIB could took place and mainly DPA-PIB with Aeff.N of77%～100%could be obtained at [DPA]/[TRPIB]=3-4in CH2Cl2/nHex (90/10, V/V) mixed solvent at60℃.<4> Telechelic PIB with disubstituted TPA as core with the maximum Aeff.N of100%could also be obtained by the alkylation of TPA with Cl-PIB-Cl in CH2Cl2/nHex (40/60, V/V) mixed solvent at40℃3. The macromolecular engineering by combination of controlled cationic polymerization with successive alkylation in One-pot Based on the cationic polymerization and the alkylation above, the controlled cationic polymerization of IB with TMPCl, H2O and DCC as initiator respectively in conjunction with TiCl4in the presence of ED (DMA or TPA) or D/BP without termination and successive alkylation with introduction of TPA in One-pot were carried out. The corresponding experimental results were indicated as follows.<1> PIB-TPA with Aeff.N of87%～93%was obtained in One-pot with IB polymerization with TMPCl/TiCl4/DMA/DtBP initiating system in the first step and then direct alkylation with TPA([TPA]/[TMPCl]=0.95～2.85) at Ta=-8℃, and PIB-TPA-PIB or triarm (PIB-)3TPA with Aeff.N of94%～100%were obtained at Ta=40℃.<2> PIB-TPA with Aeff.N of88%([TPA]/[H2O]=4.4), PIB-TPA-PIB with Aeff.N of41%([TPA]/[H2O]=1.5) and triarm (PIB-)3TPA with Aeff.N of17%([TPA]/[H2O]=0.5) were abtained in One-pot with H2O/TiCl4/DMA initiating system in the first step and then direct alkylation with TPA at Ta=50℃, respectively.<3> PIB-TPA-PIB with Aeff.N of66%was obtained in One-pot with H2O/TiCl4/TPA initiating system with second-addtion of TPA and Ta=-15℃, and that with Aeff.N of45%was obtained without second-addtion of TPA and Ta=45℃, respectively.<4> Telechelic PIB with disubstituted TPA as core with Aeff.N of93%was obtained in One-pot with IB polymerization with DCC/TiCl4/DMA/DtBP initiating system in the first step and then direct alkylation with TPA ([TPA]/[DCC]=1.1-4.3)at Ta=-80℃,and telechelic PIB with di-or tri-substituted TPA as core with Aeff.N of89%～97%were obtained at Ta=40℃. |
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