DYNAMIC BIREFRINGENCE OF AMORPHOUS POLYOLEFINS .1. MEASUREMENTS ON POLY[1-ETHYL-5-METHYL-OCTAHYDRO-4,7-METHANO-1H-INDENE-1(2),3-DIYL]

The complex strain-optical coefficient and the complex Young's modulus of an amorphous polyolefin, poly[1-ethyl-5-methyl-octahydro-4,7-methano-1H-indene-1(2),3-diyl], PEMOMID, were measured around the glass-to-rubber transition zone. The data was analyzed with a modified stress-optical rule, and two components of complex modulus, E(G)* and E(R)*, and two associated stress-optical coefficients, C(G) and C(R), were determined. The result was compared with one for a Bisphenol A polycarbonate, PC. C(R), stress-optical coefficient in the rubbery plateau zone, for the polyolefin was 1.7 x 10(-9) Pa-1 and about three times smaller than that for PC. C(G) for PEMOMID is negative and this was in contrast to a usual positive value for polymers containing phenyl rings in their re tin units.