Radical co-polymerization

A development in the synthesis of macromolecular scintillators is the radical co-polymerization of alkenes with the fluorescent co-monomer 2-t-butyl-5-(4 -vinyl-4-biphenylyl)-l,3,4-oxadiazole <89MI 406-04). Basic initiators cause ring opening of 2-phenyl-l,3,4-oxadiazolin-5-one with subsequent anionic polymerisation to form A-benzamido-1-nylon [-N(NHCOPh)CO-] <90PB583>. 

The first example of the use of a polymer-bound cinchona alkaloid in the AD was described in 1990 by Sharpless [48,49], The polymer was readily obtained by radical co-polymerization of 9-(p-chlorobenzoyl)quinidine acrylate with acrylonitrile. First applications in dihydroxylations of frans-stilbene using NMO as co-oxidant yielded products with enantioselectivities in the range of 85 -93 % ee. It is interesting that a repetitive use of the polymer was possible without great loss of reactivity, indicating that the metal was retained in the polymeric array. 

A daminozide (DZ) pesticide, a plausible carcinogen, has been determined using an MIP-QCM chemosensor [150]. Preparation of MIP particles used for fabrication of this chemosensor involved thermo-radical co-polymerization, in methanol... 

For instance, conductometric transduction has been used for determination of an atrazine herbicide in the concentration range 4.6-231.8 mM [165]. A sintered glass frit was used as the support for the MIP film prepared by thermo-radical polymerization. However, both the response time of 30 min and the chemosensor recovery time of 12 h were long. For better performance, the MIP film was prepared by photo-radical co-polymerization of a chloroform solution, which contained tri (ethylene glycol)dimethacrylate (TEGDMA), MAA, and oligourethane acrylate, sandwiched between two quartz slides (Table 6). 

Radical co-polymerization of styrene and butadiene produces a material that is very like natural rubber. The initiator is a one-electron oxidizing agent, and a thiol (RSH) is used to start the polymerization process. The mixture is about 3 1 butadiene styrene so there are no long runs of one monomer in the product. We will use butadiene as the starter unit. 

Pich and coworkers synthesized microgels by free-radical co-polymerization of vinyl caprolactam and acetoacetoxyethyl methacrylate (AAEM) in the presence of methoxy-capped PEGMA macromonomers [88], It has been reported that variation of the amount of PEG macromonomer or the length of the PEG chain provides effective control of the microgel diameter in the range 60-220nm (Fig. 6). 

The fluorinated network has been elaborated starting from 3,3,4,4,5,5,6,6,7,7, 8,8,8-tridecafluorooctyl acrylate (AcRf6) by free-radical co-polymerization with ethylene glycol dimethacrylate in the presence of DCPD as the initiator. In this case, the PDMS network could not be synthesized by thiol-ene addition... 

The reactivity ratios of various monomer combinations in the free radical co-polymerizations have been determined [5]. The reactivity ratio, rx, is defined as... 

In a paper devoted to the investigation of radical co-polymerization of vinylidene cyanide with a variety of monomers, an unusual autocatalytic behavior was reported for the pair vinylidene cyanide - vinyl ether251. The authors suggested a possible mutual co-initiation of anionic polymerization of vinylidene cyanide, inducing a cationic polymerization mode of vinyl ether. 

Io denotes the concentration of the initiator quantitatively converted into living polymers). Since u and v are two different variables, not related by the conventional equation describing the stationary state of radical co-polymerization, i.e. k2)v[S] k ufpMeS], the above three equations have to be identical, i.e. they have to represent only one relation of u to v. This is possible only if... 

Kuchanov,. I a Modern Aspects of Quantitative Theory of Free-Radical Co polymerization. Vol. 103, pp. 1-102. 

The vinyl monomer of CyD is synthesized by the ester exchange reaction of m-nitrophenyl acrylate with (3-CyD or a-CyD in water. The imprinted polymers are prepared in water by a conventional radical co-polymerization of the vinyl monomer of CyD with N,N,-methyl-enebisacrylamide (MBAA) as crosslinker in the presence of various templates acryloyl CyD (300 pmol) and template (150 pmol) are dissolved in 15 mL of Tris buffer solution ([Tris] = 5 mM, pH 8.0). After stirring for a few minutes, the polymerization is started by adding MBAA (3.0 mmol) and potassium persulfate (35 mg) under nitrogen at 50 °C. The system becomes opaque as the polymerization proceeds. After stirring for 2 h, the obtained white precipitate is collected and... 

EXAMPLES OF SEVERAL FREE RADICAL (CO)POLYMERIZATION SCHEMES AND THE RESULTING KINETIC AND MOLECULAR WEIGHT DEVELOPMENT EQUATIONS... 

Figure 19 Copolymer fingerprint of poly(STY-prad/enf-butadiene), obtained from a MALDI-ToF mass spectrum. The ratio of STY to butadiene equals 50/50 (mol/mol). Reprinted from Wiiiemse, R. X. E. New Insights into Free-Radical (Co)Polymerization Kinetics, Eindhoven University of Technology Eindhoven, The Netherlands, 2005. ...

P. H. Henna, D. D. Andjelkovic, P. P. Kundu and R. C. Larock, Biobased thermosets from the free-radical co-polymerization of conjugated hnseed oTd ,JAppl Polym Sci, 2007,104, 979-85. 

A patent was issued to Wertmer and coworkers [271] for controlled radical (co)polymerization of vinyl monomers mediated by nitrones substituted by longer alkyl groups that contained as much as 18 carbon atoms. The nitrone was simply heated in the presence of peroxide and a monomer, such as styrene at 130°C for 24 h. High-molecular-weight polystyrene, = 98,000-146,000 was formed. The ratio of however, was not disclosed... 

Sharma S., Srivastava A.K., Radical co-polymerization of limonene with iV-vinyl pytroUdone Synthesis and characterization, DesignedMonom. Polym., 9(5), 2006, 503-516. 

Cheng, C. Powell, K. T. Khoshdel, E. Wooley, K. L., Polydimethylsiloxane-(PDMS-) Grafted Fluorocopolymers by a Grafting through Strategy Based on Atom Transfer Radical (Co)polymerization. Macromolecules 2007,40, 7195-7207. 

General survey. The most common and often applied synthesis method for sf poly(meth)acrylate polymers and copolymers is radical (co)polymerization, as depicted in Figure 11.8. In general, radical polymerization is easy to perform, cheap, and reproducible. 

A typical polymer-modified organoclay for the preparation of PS nanocomposites could be a PS polymer with some cationic sites to be attached to the clay surface. Polystyryl quaternary ammonium salts (PSQAS) were synthesized via three different polymerization routes anionic polymerization (AP), free radical co-polymerization (CP), and chloromethy-lation of polystyrene (CM) [67] (Table 3.6). TGA results indicated that CP-PSQAS and CM-PSQAS were thermally stable, because the C-C bonds in aromatics are much stronger than those in aliphatic compounds. The polystyryl-modified clays exhibited intercalated or partially exfoliated structures. 

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