Compressibility of bulk polymers

Abstract

Bulk compressibilities of a series of linear and crosslinked polymers have been measured, in a Matsuoka‐Maxwell apparatus, at pressures up to 10,000 atmospheres and at temperatures to 202°C. These polymers exhibited nonlinear compressibility characteristics and a maximium compressibility of about 15% at 10,000 atmospheres. At slow loading rates, data were obtained for the amorphous polymers which could be expressed as glass‐rubber phase gisgrams. The nature of the observed compressibilities are discussed and the usefulness of the data is indicated.

Improved Lysozyme Stability and Release Properties of Poly(lactide-co-glycolide) Implants Prepared by Hot-Melt Extrusion

“…A lower process temperature can increase the density of the product because of a higher melt viscosity (32). In fact, the higher melt viscosity results in a higher pressure (33) and thus a lower free volume (34).…”

Single specimen determination of Young's and bulk moduli of polymers

“…A polystyrene rod 6.60 cm long and 0.063 cm in diameter was prepared. In fact, polystyrene has been taken to at least 10,000 atmospheres in bulk compression with no measurable dimensional effects (10). The specimen was then loaded to 1000 Kg at the standard loading rate giving the results as shown by Plot I of fig.…”

Elasticity solution for an axially compressed and encased cylindrical specimen

“…Perhaps the best known such device is the one described by Matsuoka and Maxwell [4]. Warfield [3] claimed that measurements obtained with this device yielded the bulk modulus of the sample under investigation. However, no detailed theoretical analysis has yet appeared studying the elastic deformation process taking place in a cylindrical sample encased in a tube and subjected to compression on the flat ends in a way typical of these material testers.…”

“…There have been comprehensive studies on the subject [1, Chapter 6] as well as a number of papers [2,3] that describe various testing devices in common use to carry out such determination. Perhaps the best known such device is the one described by Matsuoka and Maxwell [4].…”