Combining Boron Nitride With a Fluoroelastomer: an Enhanced Polymer Processing Additive

摘要

The effect of a new processing additive (boron nitride powder in combination with a fluoroelastomer) on the rheology and processability of molten polymers is studied. The equipment used includes an instron capillary rheometer equipped with a special annular die (Nokia Maillefer wire coating cross-head) and a parallel-plate rheometer. Metallocene polyethylenes with and without boron nitride (BN) and fluorelastomer are tested in extrusion. First, it is demonstrated that BN is a superior processing aid compared to conventional fluoropolymer ones. Second, it is found that the combination of BN powders with a small amount of a fluoroelastomer improves even further the processability of molten polymers (melt fracture performance).