Determination of the degree of mixing of rigid PVC by DSC

After polymerization, PVC is present in the form of a powder. The mean grain size amounts to about 200 μm. Each PVC grain consists of an agglomerate of primary particles which are called globules. Each grain is surrounded by a protective colloid skin (exception: PVC suspensions). Before fusion, this protective skin has to be destroyed by mechanical and thermal action. A function correlation has been formulated between fusion, mixing and the degree of fusion. The degree of fusion is a characteristic value between 0 and 1. Mixing and fusion can also occur between 0 percent and 100 percent. 0 percent denotes that there is no mixing or fusion and for 100 percent mixing or fusion, the entire material is mixed or fused.