Effect of heterocyclic derivatives of ferrocene on free-radical polymerization of methyl methacrylate and styrene

Azinyl derivatives of ferrocene for preparation of poly(methyl methacrylate) with enhanced properties

“…It was demonstrated that the metal complexes I-V combined with diacyl peroxides (benzoyl peroxide or lauryl peroxide) form highly efficient initiating systems, more active than the systems based on unsubstituted ferrocene [3][4][5], allowing for fast polymerization with high yield at lower temperatures (30-60)°С. The spectral studies confirmed that both ferrocenyl and heterocyclic fragments of compounds I-V affected the coordination with peroxide initiator [2].…”

“…The polydispersity index M w /M n was of 1.3-3.0 depending on the monomer conversion, being in general lower than in the case when the radiacl initiator was used alone (M w /M n = 2.0-4.0). Molecular mass parameters confirmed the influence of the additive on the chain growth and chain termination steps [1,2].…”

“…The mentioned ferrocenes did not interact with azobisisobutyronitrile AIBN but the overall polymerization rate of methyl methacrylate polymerization was somewhat increased, pointing at the influence of the azinyl ferrocenes on the chain growth processes in addition to that on the initiation step [2].…”

“…First, that could be due to the changes in stereochemical composition of the macromolecule (increase of the syndiotactic structures). However, the variation of the content of syndiotactic fragments upon introduction of azinyl ferrocenes in the polymerizing mixture was minor (62-64% as compared to 55-56% in the case of the reference polymer [2]); that was typical of other metallocenes as well. Another reason could be that using metal complexes as component of the initiating/ catalyzing system could enhance stability of the end fragments of the polymer chain.…”

“…Thermomechanical analysis was performed using an automated station based on a H307 bi-coordinate potentiometer taking advantage of penetration technique at constant load of the 80 mg sample (20 g/mm 2 ) and at heating rate of 2.7 deg/min, in air.…”