Processing‐morphology‐property studies of poly(vinyl chloride)

Recent morphological studies of plasticized and unplasticified poly(vinyl chloride) (PVC) are reviewed. Suspension polymerized PVC contains particles in a number of different size ranges 100–200Å, 1000–5000Å, 1μ and larger. The larger size particles are broken down during plasticization but both the 100Å and the 1000Å suspension particles retain their identity. The visibility, and presumably, coalescence of these particles is a function of the processing conditions. In particular, the size of the 100Å particle increases with plasticizer content and is most distinct as characterized both by small angle x‐ray scattering and electron microscopy for milling temperatures in the 160–170°C. range. Consideration is given to the effect of these particles, their structure, and interrelationship on the rheological properties of the resins.