Two decades of high-polymer physics: A survey and forecast

Abstract

The twentieth anniversary of the founding of the Division of High-Polymer Physics of the American Physical Society is an appropriate time to review the progress of polymer physics over the last two decades, and to re-evaluate the hopes of the founders and the present need for the Division. The continuing need for our Division perhaps is best shown by the fact that each of the last two meetings have set new records for the number of papers presented. Much of this progress is due to the officers who have contributed so much of their time and effort to the Division. Those who served in the first decade were recognized in an earlier review. The officers of the last decade are shown in the accompanying table. We are indebted to all these men for their work to keep the Division running, and thus promote the progress of polymer physics.

Macromolecules in nonhomogeneous flow fields: A general study for dumbbell model macromolecules

“…Proceeding as before, it can be shown that this implies: shows this quite clearly• According to (6.2a), this implies that n~' monotonically increases towards the wall, and figure 5 shows a sample calculation. The result is at odds with basic thermodynamic arguments [4], and we are not aware of any experiments which 13) In this connection, recall the remarks following eq. (2.16).…”

“…Here (6h)) denotes the expectation value of the vector /@, while the diffusion dyadic D is defined by (note that Br is a symmetric dyadic) 4) n D= kTS d3 X BTv. respectively, means that we admit only the dumbbells which -at least in some average sense -are slender.…”

“…The speculation that a thermodynamic driving force causes the molecules to move from the high shear region (close to the wall) to the low shear region (dose to the axis) has been advanced some time ago [4]. Although this hypothesis has been put on more quantitative terms [5,6], the validity of the speculation itself is open to question [7].…”

Phase-separation kinetics in dynamically asymmetric binary fluids: Viscoelastic effects in polymer solutions

“…Although it is well known that the external shear field shifts the apparent phase diagram and strongly affects spinodal decomposition [ 19,[14][15][16], this kind of viscoelastic effect due to the self-induced, internal velocity field has never been considered, and further theoretical studies are necessary to clarify the effect and to establish this concept. There are many possibilities for new effects: for example, the local velocity field induced by phase separation might shift the local critical temperature during the phase separation.…”

Characterization of die drool sample produced by HDPE melt extrusion

“…Historically, the first notice about polymer melt spontaneously fractionating during flow under inhomogeneous stresses in capillary was presented in 1964 by Busse [1]. On the theoretical level he claimed that "capillary viscometer should tend to fractionate polymer molecules with respect to molecular weight along the radius of the capillary."…”