Lubrication mechanism of poly(vinyl chloride) compounds: Changes upon PVC fusion (gelation)

Poly(vinyl chloride) (PVC) compounds perform best with adequate metal lubrication and polymer‐to‐polymer lubrication of PVC primary particle flow units. Much of the mechanism for the lubrication of PVC has been elucidated over the years. One point has not been completely understood, which is the “lubricant failure” at higher processing temperatures where the compound is known to become less ductile. This result is contrary to what might be expected with better PVC fusion (gelation). This article discusses the mechanism involved, which is lubricant inversion, where the lubricant goes from the continuous phase, as a surfactant coating all the PVC primary particle flow units at lower melt temperatures, to become the discontinuous phase at higher melt temperatures. J. VINYL. ADDIT. TECHNOL., 11:57–62, 2005.