Molecular weight distribution rheological properties

The dependence was found to be valid for entangled, narrow molecular weight distribution blends of poly(ethylene-olt-propylene) with head-to-head PP (polypropylene) [192], and for blends of linear and branched PE (polyethylene) with similar molecular weights and rheological properties [193]. 

Harris, F. W. et al. State of the Art Polymer Chemistry. /. Chem. Educ. 1981,58, (Nov). (This issue contains 17pap>ers on jxjlymer chemistry. The series covers structures, properties, mechanisms of formation, methods of preparation, stereochemistry, molecular weight distribution, rheological behavior of polymer melts, mechanical properties, rubber elasticity, block and graft cojxjlymers, organometaUic polymers, fibers, ionic polymers, and polymer compatibility.)... 

The molecular weight distribution is an important parameter for controlling the rheological and processing properties of rubber ... 

Mills, N.J. The rheological properties and molecular weight distribution of poly-dimethylsiloxane. European Polymer J. 5,675-695 (1969). 

Kulicke W-M, Elsabee M, Eisenbach CD, Peuscher M (1983) Effect of the molecular weight and molecular weight distribution on the rheological properties of aqueous polyethylenoxide solution Polym Bull 9 190... 

Polyethylene is a man-made homopolymer. Its chemical synthesis is well understood. It is a random walk polymer with little secondary or tertiary structure. A batch can largely be characterised by its molecular weight distribution, and its rheology can be related to these parameters by developed rules of polymer behaviour. The action of specific chemicals as plasticisers can be used to modulate these bulk properties in a predictable way, allowing the nature and characterisation of its glass to fluid transition to be predicted. 

Anionic polymerization, however, can be used to produce high molecular weight narrow distribution polystyrene. If all the chains are initiated at the same time and the temperature is kept low to minimize chain transfer, molecular weight distributions very close to monodisperse can be produced. The commercial uses of these polymers seem to be limited to instrument calibrations and laboratory studies of the effects of molecular weight on rheology and physical properties. However, anionic polymerization as a potential commercial method for producing polystyrene has been extensively studied by Dow and others. The potential for high polymerization rates, complete conversion of... 

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