ChemInform Abstract: POLYMERIZATION OF METHYL METHACRYLATE WITH THE CHLOROCARBONYLBIS(TRIPHENYLPHOSPHINE)RHODIUM(I)-ORGANIC HALIDES SYSTEM

1973 ◽  
Vol 4 (44) ◽  
Author(s):  
NORIYUKI KAMEDA ◽  
NORIKO ITAGAKI
1967 ◽  
Vol 22 (6) ◽  
pp. 580-586 ◽  
Author(s):  
C. H. Bamford ◽  
R. Denyer ◽  
G. C. Eastmond

In a series of publications we have described the kinetics of free-radical formation from molybdenum carbonyl in association with organic halides in a number of electron-donating solvents. Radical formation involves the displacement of carbon monoxide from the carbonyl by the solvent or vinyl monomer in a rate-determining process giving rise to complexes of the type Mo (CO)5L (where L represents the solvent or monomer) which then react directly with the halide. This paper describes a study of the behaviour of Mo (CO)5Py in association with organic halides in methyl methacrylate solution. The results show that Mo (CO)5Py does not react directly with the halide but first undergoes activation by reaction with monomer, mainly with displacement of pyridine. The relative reactivities of complexes of the type Mo (CO)5L are discussed.The mechanism previously proposed to account for the inhibition processes observed in Mo (CO) 6-organic halide systems satisfactorily explains the extensive inhibition observed in the present work.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2747
Author(s):  
Ming Yuan ◽  
Lili Xu ◽  
Xuetao Cui ◽  
Jiaxing Lv ◽  
Panpan Zhang ◽  
...  

A facile and versatile approach for the synthesis of ultrahigh molecular weight poly(methyl methacrylate) (PMMA) at mild conditions was developed. Certain organic halides combined with a catalytical amount of palladium nanoparticles (Pd NPs) were found to be very effective in initiating polymerizations of methyl methacrylate (MMA), methyl acrylate, vinyl acetate and other vinyl monomers. An ultrahigh molecular weight PMMA with a number-average molecular weight of 4.65 × 106 Da and a weight-average molecular weight of 8.08 × 106 Da was synthesized at 70 °C using 2-bromoisobutyric acid ethyl ester (EBiB) as an initiator in the presence of catalytical amount (10.1 ppm) of Pd NPs. A kinetic investigation found that the orders of polymerization with respect to EBiB, Pd NP and MMA were 0.23, 0.50, and 0.58, respectively. Proton nuclear magnetic resonance (1H NMR) combined with matrix-assisted laser desorption ionization time of flight mass spectroscopy (MALDI-TOF) and gel permeation chromatography (GPC) were used to prove that the macromolecular chain had an end-group of EBiB residue. The electron spin resonance (ESR), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) results reveal that the reaction of EBiB with Pd NPs caused a bromo atom (Br) transfer from EBiB to Pd NPs and resulted in the generation of EBiB residue radical to initiate the polymerization of MMA and the formation of PdIIBr2 on the surface of Pd nanoparticles.


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