Instrument Rheological Measurements Rheological properties were carried out by using a capillary rheometer device (Instron model 3211), ASTM D-3835. The diameter of the capillary is 0.76 mm, the length to diameter (L/D) ratio of 80.9, with an angle of entry of 90°. Load weighing which dropped on the polymer melts by plunger transversed from the top to the bottom of the barrel was constant (2,000 kg). The constant plunger speeds ranged from 0.06 to 20.0 cm.min-1, the extrusion temperature was 140°C.