FURTHER EXPERIMENTAL-EVIDENCE FOR INTRAMOLECULAR SCREENING IN POLYMERBLENDS

Intramolecular screening in hydrogen-bonded polymer blends has its gen esis in chain connectivity. The covalent linkages that occur between p olymer segments results in an accentuation of the number of same-chain contacts compared to that calculated on the basis of a simple random mixing of segments. Using experimental infrared spectroscopic data der ived from blends of random copolymers of n-butyl methacrylate-stat-4-v inylphenol with styrene-stat-2-vinyl pyridine, strong evidence for the presence of intramolecular screening has been obtained. This is a sig nificant factor that must be taken into consideration in theories of t he mixing of polymers.