How the morphology of poly (vinyl chloride) compounds affects toughness and weatherability

摘要

AbstractSuspension polymerized poly (vinyl chloride) (PVC) is made up of 150 μm grains. Within these grains are 2 μm primary particles which apparently become the flow units under low melt temperature (175°C) extrusion conditions. The 2 μm particles are visible by light transmission microscopy by shearing the extruded product between glass slides after swelling in acetone or by electron transmission microscopy of ultrathin microtomed samples. This product, made up of 2 μm flow units, is brittle and has poor toughness retention upon weathering. At higher melt temperatures (185–190°C), agglomeration of the 2 μm particles occurs, giving a rough surface but tougher product. At higher melt temperatures, a continuous melt occurs, leading to a smooth surface and tough product with excellent toughness retention upon we