Enhanced polycarbonate toughness. I: Measurement methodology

Abstract

The J,, values for core-shell-particle-toughened polycarbonate were determined at different temperatures and at 0, 2.5, 5.0, 7.5, and 10.0 phr particle content by six similar methods, using compact tensile specimens. At the 2.5 phr toughener level, the J,, values ranged from 2878 to 6100 J/m2, and at 7.5 phr, they ranged from 6125 to 10,760 J/m2, dependent only upon how the same J, -h a data were interpreted. This indicates that more work will be required before a reliable method of J,, measurement that can be applied to tough polymers is achieved. 1992).

Effects of external electron donor on catalyst active sites in propylene polymerization

“…This can be explained by chemical phenomena, such as active site reduction from Ti /4 to Ti /3 or Ti /2 by cocatalyst. [16][17][18] However, physical phenomena must not be ignored to explain this deactivation. That is, a polymer shell is formed around the catalyst particle with reaction time, and then monomers have difficulties in diffusion to the catalyst surface through the polymer shell.…”