Prepation Of Self-Assembly Polymer Network Via Hydrogen Bonds

Thermally reversible non-convalent hydrogen-bonded was introduced into Butyl Rubber via the reaction of Brominated IIR with 4-aminouracil.Reaction of Brominated Butyl Rubber with 4-aminouracil was carried out under the phase transfer catalyst. The effect of reaction time, temperature, catalyst and the amount of 4-aminouracil on the substitution of allylic Br in BIIR with 4-aminouracil was investigated. The results show that exo allylic Br is substituted by 4-aminouracil firstly, then endo allylic Br is done. But the substitution isn't quantitatively completed. The conversion can reach 76% at 80℃and tetrabutyl ammonium bromide as a phase transfer. DSC indicates there is still hydrogen bonding, forming the thermally reversible crosslinkage in IIR, although few 4-aminouracil are incorporated. The tensile strength tripled compared to BIIR.Meanwhile, the reaction of poly(isobutylene-co-p-methylstyrene-co-p-bromomethylstyrene) (BIMS) with 4-aminouracil was carried out. The effect of kinds of BIMS, reaction time, temperature and the amount and concentration of 4-aminouracil on the substitution of Br in BIMS with 4-aminouracil was investigated. The results show that the the substitution of Br can reach 69% at 90℃for six hours. The reaction yields gel, and the amout of gel increases along with reaction time as reaction time exceeded 12 hours.