Block polymers definition

However, identification of cationic block polymers has not always been definitive because of the complexities of the reaction systems and a failure to do complete characterization studies on the polymers. 

A definitive picture of the phase structure emerged and was made possible by the simultaneous development of powerful investigative techniques such as phase staining/electron micrography, low-angle X-ray diffraction, and GPC which were combined with conventional physicochemical characterizations of bulk, melt, and solution states of the block polymers. 

Definition Polyoxyethylene, polyoxypropylene block polymer of ethylene diamine... 

Definition Polyoxyethylene, polydodecyl glycol block polymer Properties Nonionic... 

Definition Polyoxyethylene, polydodecyl glycol block polymer Properties Nonionic Uses Emulsion stabilizer, emollient in cosmetics surfactant, stabilizer for w/o emulsions... 

Definition Polyoxyethylene, polyoxypropylene block polymer of ethylene diamine Properties Nonionic Toxicoiogy TSCA listed Uses Emulsifier, thickener, wetting agent, dispersant, solubilizer, stabilizer in cosmetics, pharmaceuticals demulsifier in petrol, industry detergent ingred. antistat for polyethylene and resin molding powds. polymerization in latex-based paints, aq.-based syn. cutting fluids and vulcanization of rubber... 

Classification Thermoplastic polymer Definition Polymer of methyl methacrylate hard transparent amorphous material Empirical (CsH802)x Formula [CH2CCH3COOCH3]n Properties Powd., gran., cast sheet and block sol. in ethyl acetate, chlorinated soivs. m.w. 60,000 (molding grades), 1,000,000 (cast sheet) dens. 1.188 ref. index 1.4100 tens. str. 72 MPa tens, mod. 2400 MPa... 

All of the more important methods of producing block polymers with long blocks utilize the living polymer method. To obtain definitive block lengths, the growing chain ends may not undergo termination or transfer reactions. Consequently, anionic polymerizations are more suitable than cationic polymerizations (see also Chapter 18). 

A major 1981 lUPAC document (9) addresses polymer stereochemistry in depth. Key chapters of this document discuss basic definitions (configurational unit, configurational base and repeating units, stereorepeating imit, different types of tacticity, tactic block polymers, and stereoblock polymers) sequences conformations and supplementary definitions. Most of the illustrations use the rotated Fischer projections, but some three-dimensional representations are included. 

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