THE METHOD OF MEASURING MACROMOLECULAR ENTANGLEMENTS OF POLYMERS USING SWELLING DIFFERENTIAL SCANNING CALORIMETRY (DSC)

Since Bueche, Graessley, Onogi, etc., advanced the concept of macromol ecular entanglements, the subject has been studied extensively. So far , there are two kinds of methods of measuring the entanglements in a p olymer system: One is the measurement of viscosity or other related pr operties of polymer fluids, either melts or solutions; the other is th e measurement of modulus or other related properties of completely amo rphous polymers. Until now, the effective method of measuring macromol ecular entanglements for crystalline or semicrystalline polymers and f ibers has not been developed. We report here a new method of measuring macromolecular entanglements of polymeric solids-using swelling diffe rential scanning calorimetry (swelling DSC or SDSC), and we prove that the entanglements in fibers and polymeric materials can be measured q uickly and conveniently with this method. (C) 1994 John Wiley & Sons, Inc.