Molecular weight suppression polymer density

The polymer yield increased with the current density at the constant electricity, although the molecular weight of the obtained polymer remained constant. The polymerization rate was related to the current density on the electrode, i.e. the concentration of the activated phenol. When the reaction solution was vigorously stirred, the polymer formation was much suppressed and yield of the dipheno-quinone through C-C coupling increased. This result suggests that the polymerization occurs on the surface region of electrode or within the diffusion layer on electrode. 

This section will deal with suppression of flow in extension of molten polymers in the region of significant elastic strains21 24 . The study of polyisobutylene 11-20 23,35) failed to reveal such phenomena (the velocity of irreversible strain ep = d(ln[3)/dt increased strictly with time). Retardation of polymer fluid flow is considered on the example of homogeneous extension at constant strain velocity and force. Most experiments were carried out with commercial low-density polyethylene (LDPE) with molecular weight MW 105. Figure 7 gives experimental dependencies of tensile force F/S0 and irreversible strain In 3 ( 3 = e/ot) upon time t at different... 

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