this polymer is sold by eastman chemical products inc under the name petg 6763 this polymer is neither crystalline nor liquid crystalline and is taken to be representative of amorphous linear polymers polymer a and polymer b were each injection molded from the melt into a 23 u00b0 c mold for a 1 16 34 u00d7 3 34 u00d7 3 34 plaque injection molding had been found in the past to generate anisotropic properties with liquid crystalline materials see table 1 table 1______________________________________orientation effects of polymer a frominjection molding from plot in w j jackson jr andh f kuhfuss j of polym sci polym chem ed 1976 14 2043 flow flex modulusorientation k psi ______________________________________isotropic 300anisotropic flow direction 2 450across flow 200______________________________________ isotropic properties are generated by molding very thick moldings while anisotropic properties are generated by molding thin moldings the injection molded plaques were micropulverized to less than 1 mm grain size the resulting fibrous fluffy material was placed in a 5 875 34 inner diameter piston like steel mold equipped with a port for vacuum evacuation the mold was then sealed evacuated and placed between the hot plates of a wabash press the pressure was gradually stepped up to about 3 820 psi and held for 10 to 60 minutes at various temperatures as shown in table 2 young 39 s modulus was measured on a du pont dynamic mechanical analyzer dma modulus at 20 u00b0 c is presented in table 2 also presented are the moduli of controls molded in thicker moldings which show less orientation polymer c was injection molded into 1 8 34 u00d7 1 2 34 u00d7 5 34 bars these bars were gripped in clamps and hung in a 120 u00b0 c oven until they.