DYNAMIC BIREFRINGENCE OF AMORPHOUS POLYOLEFINS .1. MEASUREMENTS ON ETHYL-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, thyl-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 resu lt was compared with one for a Bisphenol A polycarbonate, PC. C(R), st ress-optical coefficient in the rubbery plateau zone, for the polyolef in was 1.7 x 10(-9) Pa-1 and about three times smaller than that for P C. C(G) for PEMOMID is negative and this was in contrast to a usual po sitive value for polymers containing phenyl rings in their re tin unit s.