scholarly journals RADICAL INITIATED COPOLYMERIZATION OF METHYL METHACRYLATE AND ACRYLONITRILE IN PRESENCE OF IRON COMPLEXES

Author(s):  
Ruslan R. Galimullin ◽  
Natalya N. Sigaeva ◽  
Sergey V. Kolesov

This article represents data on the effect of organometallic iron complexes: ferrocene, dicarbonyl dimer of cyclopentadienyl iron and tricarbonyl cyclooctatetraene iron on the copolymerization of methyl methacrylate (MMA) and acrylonitrile (AN) initiated by benzoyl peroxide. It is shown that the introduction of metal complexes and their structure affect the initial rate of copolymerization, the form of the diagrams of the composition of the obtained copolymers, and the values of the effective constants of the relative activities of the comonomers in the copolymerization of methyl methacrylate and acrylonitrile (system metallocomplex of iron – peroxide benzoyl: ferrocene – peroxide benzoyl: rММА = 1.58; rАН= 0.08 in 60 °С; rММА = 1.30; rАН = 0.05 in 50 °С; dicarbonyl dimer cyclopentadienyl iron–peroxide benzoyl: rММА = 1.36; rАН = 0.06 in 60 °С; rММА = 1.09; rАН = 0.14 in 50 °С; tricarbonyl cyclooctatetraene iron -peroxide benzoyl: rММА = 1.08; rАН = 0.15 in 60 °С; rММА = 1.14; rАН = 0.05 in 50 °С; peroxide benzoyl: rММА = 1.11; rАН = 0.07 in 60 °С; rММА = 1.11; rАН = 0.07 in 50 °С). The proportions of triadic sequences of units in copolymers, experimentally determined from 1H NMR spectroscopy, are given, as well as the calculated proportions of dyads. The presence of iron metal complexes affects the distribution of the proportions of the triad and dyad sequences of units, as well as their microstructure in copolymers. These changes are explained by the formation of macromolecules, both with the participation of free radicals and the stereospecific coordination active centers of polymerization that are formed in the presence of iron complexes.

2010 ◽  
Vol 93-94 ◽  
pp. 39-42
Author(s):  
Sirichai Piyaauksornsak ◽  
Boonchoat Paosawatyanyong ◽  
Napida Hinchiranan

The graft copolymerization is one chemical modification methods to improve natural rubber (NR)’s properties via both solution and latex phases. To enhance the polarity of NR, methyl methacrylate (MMA) was applied for graft copolymerization of NR in the presence of thermal or redox initiators. However, the conventional graft copolymerization generally spends long reaction time (ca. 6-8 h). Due to less energy consumption with faster heating rate, the microwave irradiation was used to induce graft copolmerization of MMA onto NR latex using redox initiation system. By comparing with the conventional grafting method at the same grafting properties, the graft copolymerization of MMA onto NR induced by microwave at 100 W spent the shorter reaction time ca. 15 min; whilst, the conventional method required the longer reaction time as 7 h. The influence of microwave power on the grafting properties was investigated. The structure of graft product was also analyzed by using FTIR and 1H NMR spectroscopy.


2010 ◽  
Vol 44-47 ◽  
pp. 3036-3040
Author(s):  
Yu Jing Nie ◽  
Zheng Zai Cheng ◽  
Rui Lei ◽  
Xiao Chao Yan ◽  
Su Su Lin

One binuclear mono-cyclopentadinyl titanocene, CpTiCl3(CH2)4CpTiCl3, has been synthesized by a new ways and characterized by 1H-NMR spectroscopy and elemental analysis. Its aqueous medium polymerization properties of methyl methacrylate (MMA) have been pursued with an anionic surfactant, sodiumn dodecylsulfate(SDS) in water. The obtained polymers were characterized by gel permeation chromatography(GPC). GPC results showed that the dinuclear titanium complex might provide PMMA with broad PDI(PDI=10.82). Influences of reaction parameters, such as temperature, time, MMA/Cat(molar ratio) and water amount were studied in detail. Under the conditions of the temperature was 55 °C, the reaction lasted l5h, the molar ratio of Cat to MMA was l:200, and the volume of water consumed was 40 ml, the conversion of MMA was as high as 70%.


Sign in / Sign up

Export Citation Format

Share Document