The effect of 1,3:2,4-bis-O-(p-methlbenzylbenzylidene)-D-sorbitol(PDTS) on uniaxial elongational viscosity of polypropylene

概要

論文の詳細を見る
We investigated the dynamic viscoelasticity and elongational viscosity of polypropylene (PP) containing 0.5wt% of 1,3:2,4-bis-O-(p-methylbenzylidene)-D-sorbitol (PDTS). The PP/PDTS system exhibited a sol-gel transition (Tgel) at 193 °C. The critical exponent n was nearly equal to 2/3, in agreement with the value predicted by a percolation theory. This critical gel is due to a three-dimensional network structure of PDTS crystals. The elongational viscosity behavior of neat PP followed the linear viscosity growth function 3η+(t), where η+(t) is the shear stress growth function in the linear viscoelastic region. The elongational viscosity of the PP/PDTS system also followed the 3η+(t) above Tgel, but did not follow the 3η+(t) and exhibited strong strain-softening behavior below Tgel. This strain-softening can be attributed to breakage of the network structure of PDTS with a critical stress (σc) of about 104 Pa.