The Effect Of Lewis Acid On Secondary Chloride-Initiated Atom Transfer Radical Living Polymerizations Of MMA | Posted on:2007-10-29 | Degree:Master | Type:Thesis | Country:China | Candidate:Y L Wang | Full Text:PDF | GTID:2121360185962848 | Subject:Materials science | Abstract/Summary: | PDF Full Text Request | Butyl chloride (SBC) in the presence of aluminium trichloride (AlCl3), successfully initiated the atom transfer radical polymerization of methyl methacrylate (MMA) with the iron dichloride tetrahydrate (FeCl2·4H2O) / triphenyl phosphine (PPh3) as catalyst in n-butanol at 80℃. The results showed that MMA can polymerize with controlled characteristic when Fe/Al=l:l. The polymerization is first order reaction with respect to monomer concentration from the kinetics plot. The polymerization displayed living character as evidence by a linear increase of molecular weight with conversion and a relatively narrow molecular weight distribution (MWD). Moreover the polymer was charactered with GPC and 1H-NMR respectively. Initiator fragment was founded in polymer by 1H-NMR. The polymerization of styrene initiated by PMMAC1 continued and another polymer with larger molecular weight was got All these above proved that the polymerization had the characteristics of controlled/"living" radical polymerization. The effect of AlCl3 was discussed and the mechanism of atom transfer radical polymerization of MMA by SBC/AlCl3 was presumed.When ruthenous chloride triphenyl phosphine (RuCl2(PPh3)3) was replaced for FeCl2 as catalyst, polymerization of MMA initiated by SBC in toluene at 80 ℃ indicated living characteristic. Not only the plot of ln[M]0/[M]t displayed first order kinetics, but also the molecular weight increased linearly with the conversion of monomer, and the polymerization rate increased in the ratio of Ru/Al=10:1. Using Al(i-Bu)2(OBu) to replace AlCl3, the polymerization of MMA had living feature and the initiation activity was improved. The conversion of monomer increased to 70%. However there was still an inducing period. While there was no an inducing period in ATRP of MMA catalyzed by SBC/FeCl2/PPh3/Al(OBu)3 with the mole ratio of...
| Keywords/Search Tags: | ATRP, SBC, MMA, PVC, Lewis acid | PDF Full Text Request | Related items |
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