Trialkyl aluminum methacrylate monomer

The alkyl methacrylate monomers were available from various sources. Isobutyl methacrylate (IBMA) (Rohm and Haas) and t-butyl methacrylate (TBMA) (Rohm Tech) may be purified first by distillation from CaH, followed by distillation from trialkyl aluminum reagents as described in detail earlier (20,21). In particular, t-butyl methacrylate (b.pt. 150°C) was successfully purified by distillation, from triethyl aluminum containing small amounts of diisobutyl aluminum hydride. The trialkyl aluminum and dialkyl aluminum hydride reagents were obtained from the Ethyl Corporation as 25 weight percent solutions in hexane. The initiator, -butyllithium, was obtained from the Lithco Division of FMC, and analyzed by the Gilman "double titration" (22). 

These results lead to the belief that trialkyl aluminums may be ideal purification agents for methacrylate monomers, as the requirements for the ideal methacrylate purification agent are ... 

Lewis acids such as methylaluminum diphenolates and trialkyl- and triarylaluminum compounds also accelerate the polymerization of methacrylic esters via aluminum porphyrin enolate (Figure 22). The acceleration effects of trialkylalumi-num in the polymerization of tert-butyl methacrylate (tBMA) and MMA were attributed to monomer activation and suppression of aluminum porphyrin degradation presumably through steric repulsion between the bulky porphyrin ligands and the Lewis acid. - 3 More details can be found in reviews by Aida " and Sugimoto and Inoue. ... 

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