New Polymerization Methods

The period following the Second World War saw the emergenee, with an accelerated speed, of new polymerization methods in 1953-1954, polymerization catalysis by coordination was developed by K. Ziegler and G. Natta (Nobel Prize, 1963), which led to for high-density polyethylene (PEHD) and polypropylene (PP). Anionic polymerization and the concept of living polymerization proposed by M. Szwarc in 1956 led to the design of blocks copolymers and the first macromolecular architectures. We then saw the emergence of catalysis by metallocene in 1980 by W. Kaminski. Radical polymerization controlled by M. Sawamoto and K. Matyjaszewski in 1994 combined the benefits of radical and ionic polymerization without the drawbacks of the former. 

S. Subramanyam, A. Blumstein, Conjugated ionic polyacetylenes. 2. A new polymerization method for substituted acetylenes, Makromolekulare Chemie - Rapid Communications 1991, 12, 23. 

For the polystyrene/solvent systems listed (Caneba, 1992a, b), careful selection of the solvent(s) permitted the FRRPP process to be carried out at a relatively low temperature, which made this new polymerization method more promising. For high LCST systems, specially designed reactors can be used to carry out the FRRPP process. However the limitation is, the higher the temperature, the more likely the incipience of thermal degradation in the system. Additionally, running the free-radical... 

Furukawa, J. and T. Saegusa, Polymerization of Aldehydes and Oxides , Interscience, New York, 1963. The history of research on polyethers is reviewed and recent studies of new polymerization methods, new catalysts, polymerization mechanisms and properties of the resulting polymers are discussed (Polym. Rev., vol. 3). 

New polymerization method for the PFSA ionomer such as supercritical carbon dioxide (SC-COj) polymerization is applied in our lab. CO2 is environmentally benign, nonflanunable, and readily available. Moreover, it can offer some benefit for... 

Since the manuscript was completed there has been much progress in hyperbranched pol)miers. Readers may investigate the vibrant activities through a few review articles [103-107] and articles on the pol)mierization mechanism, especially the cyclization reaction [108-109], new characterizations, classification of branching [110-113], and some new polymerization methods [114—116]. 

A new process, from Norway, has filled the size gap between emulsion and suspension polymerization techniques [7,8]. This novel polymerization method, the so-called swollen emulsion polymerization has been developed by Ugelstad for producing uniform polymeric particles in the size range of 2-100 /nm. This process comprises successive swelling steps and repolymerizations for increasing the particle size of seed polymer particles by keeping the monodispersity of the seed latex. 

The synthesis of new polymeric materials having complex properties has recently become of great practical importance to polymer chemistry and technology. The synthesis of new materials can be prepared by either their monomers or modification of used polymers in industry. Today, polystyrene (PS), which is widely used in industrial applications as polyolefins and polyvinylchlorides, is also used for the production of plastic materials, which are used instead of metals in technology. For this reason, it is important to synthesize different PS plastic materials. Among the modification of PS, two methods can be considered, viz. physical and chemical modifications. These methods are extensively used to increase physico-mechanical properties, such as resistance to strike, air, or temperature for the synthesizing of new PS plastic materials. 

Both new catalysts and new processes need to be developed for a complete exploitation of the potential of CO2 use [41]. The key motivation to producing chemicals from CO2 is that CO2 can lead to totally new polymeric materials and also new routes to existing chemical intermediates and products could be more efficient and economical than current methods. As a case in point, the conventional method for methanol production is based on fossil feedstock and the production of dimethyl carbonate (DMC) involves the use of toxic phosgene or CO. A proposed alternative production process involves the use of CO2 as a raw material (Figure 7.1)... 

Webster OW (2004) Group transfer polymerization mechanism and comparison with other methods for controlled polymerization of acrylic monomers. In New synthetic methods. Advances in polymer science, vol 167. Springer, Berlin, pp 1-34... 

Majoros, L, Nagy, A. and Kennedy, /, P, Conventional and Living Carboeationic Polymerizations United. 1. A Comprehensive Model and New Diagnostic Method to Probe the Mechanism of Homopolymerizations. Vol 112, pp. 1-113. 

Alig et al. [194] have reviewed new ultrasonic methods for characterisation of polymeric materials. 

We report here the results of our recent studies of poly(alkyl/arylphosphazenes) with particular emphasis on the following areas (1) the overall scope of, and recent improvements in, the condensation polymerization method (2) the characterization of a representative series of these polymers by dilute solution techniques (viscosity, membrane osmometry, light scattering, and size exclusion chromatography), thermal analysis (TGA and DSC), NMR spectroscopy, and X-ray diffraction (3) the preparation and preliminary thermolysis reactions of new, functionalized phosphoranimine monomers and (4) the mechanism of the polymerization reaction. 

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