Polymerization characterization

Moore, E. P. Jr. Polypropylene Handbook Polymerization, Characterization, Properties, Applications Hanser Munich, 1996. 

Novel sulfonated and carboxylated ionomers having "blocky" structures were synthesized via two completely different methods. Sulfonated ionomers were prepared by a fairly complex emulsion copolymerization of n-butyl acrylate and sulfonated styrene (Na or K salt) using a water soluble initiator system. Carboxylated ionomers were obtained by the hydrolysis of styrene-isobutyl-methacrylate block copolymers which have been produced by carefully controlled living anionic polymerization. Characterization of these materials showed the formation of novel ionomeric structures with dramatic improvements in the modulus-temperature behavior and also, in some cases, the stress-strain properties. However no change was observed in the glass transition temperature (DSC) of the ionomers when compared with their non-ionic counterparts, which is a strong indication of the formation of blocky structures. 

Surfactant Monomers Morphology before polymerization Morphology after polymerization Characterization of the isolated polymer Remarks Reference... 

The concentrated solution viscosity measurement yields the weight-average degree of association of active chain ends rather than the more conventional number-average (mole fraction) value. However, the calculation of the equilibrium constant for association, K, can be accomplished if and the heterogeneity index of the polymer sample are known. The latter parameter can be determined via post-polymerization characterization. 

Tip 16 Polymerization of methyl methacrylate, styrene, and vinyl acetate. MMA, when polymerized, exhibits termination by both combination and disproportionation (in fact, disproportionation is promoted at higher temperatures). Termination by disproportionation leads to the formation of radicals and, eventually, polymer molecules with a TDB. We also know that TDBs will become competitive with the monomer vinyl bonds for radicals as conversion increases. TDB polymerization (characterized by rate constants close (in value) to propagation rate constants) leads to trifunctional LCB. Yet, upon analysis, poly(MMA) chains are linear. How come What is the explanation/reasoning for this observation We also know that styrene terminates predominantly via combination. Styrene also exhibits transfer to monomer, which is enhanced at higher temperature levels. Transfer to monomer generates chains with TDBs. Yet, polystyrene is linear. What is the explanation ... 

Moore EP Jr (ed) (1996) Polypropylene handbook polymerization, characterization, properties, applications. Hanser, Munich... 

Chung TS, editor. Thermotropic liquid crystal polymers thin-film polymerization, characterization, blends, and applications. Lancaster, PA TechnomicPub. Co. 2001. ISBN 1566769434. 

Albizzati, E. Giannini, U. Collina, G Noiisti, L. Resconi, L. Catalysts and Polymerizations. In Polypropylene Handbook Polymerization, Characterization, Properties, Processing, Applications Moore, E. R, Ed. Hanser Munich, 1996 pp 11-111. 

Georgiou TK, Vamvakaki M, Patrickios CS (2004) Nanoscopic cationic methacrylate star homopolymers synthesis by group transfer polymerization, characterization and evaluation as transfection reagents. Biomacromolecules 5 2221-2229... 

Molar masses of the samples were determined by field-desorption mass spectrometry (FD-MS), vapour pressure osmometry (VPO), and GPC. GPC was calibrated with PVFc. Both, calibration via an oligomer sample in which oligomers from = 3 through n = 11 could be identified and via polymers produced by living anionic polymerization (characterized by VPO or FD-MS), gave similar results and excellent agreement with theoretical values. 

Billmeyer F. W., Textbook of Polymer Science , Wiley, New York, 1984. An up-to-date textbook that has chapters on polymerization, characterization, properties and polymer processing. 

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