The highly reactive polyisobutylenes (PIBs) with alpha-double bonds (87.5 mol%) or tert-chloro (tert-Cl) groups ( 95 mol%) could be prepared via the cationic polymerization of isobutylene (IB) coinitiated by BF3 or TiCl4 respectively. The Friedel-Crafts alkylation of diphenylamine (DPA) with the highly reactive PIB with a alpha-double bonds was further conducted under different conditions, such as at different alkylation temperature, in the mixed solvents of CH2Cl2/n-hexane with different solvent polarity and at DPA concentration ([DPA]). The resultant PIBs with sec-arylamino terminal groups were characterized by GPC with RI/UV dual detectors and H-1-NMR spectrum. The experimental results indicated that alkylation efficiency increased with increases in reaction temperature, solvent polarity and [DPA]. The 77 mol% of sec-arylamino terminated PIBs could be obtained in 10/90 (V/V) mixture of nHex/CH2Cl2 with [DPA]/[PIB]of 3.0 at 60 degrees C for 45 h. Moreover, the alkylation of DPA with highly reactive PIBs with mainly tert-Cl terminal groups was also carried out in 10/90 (V/V) mixture of CH2Cl2/nHex with [DPA]/[PIB]=3.0 at 60 degrees C for 45 h, and almost monoalkylation with 100 mol% sec-arylamino terminal groups could be achieved. These results will help further explorations of the molecular engineering via combination of cationic polymerization with alkylation.

The mechanism and new stage in controlled/living cationic polymerization of vinyl monomers, such as isobutylene, styrene, vinyl ether, are reviewed. The novel initiating systems including metallocene, Lewis acid with a weak base, Lewis acidic diboranes, water-tolerant acid, and the cationic polymerization in aqueous media are summerized. The advanced thermoplastic elastomer based on polyisobutylene via controlled/living cationic polymerization is used as biomaterials.