| Popis: |
The main ideas about the new theory of PVC decomposition are described; they tackle such key questions as the chemical structure and the contents of anomalous groupings in the PVC, their effects on the thermal stability of the products, and the kinetics of HCl elimination. In contrast with the generally accepted β-allyl chloride activation of the PVC decomposition was developed the concept of oxygen-containing groups having the structure ∼C(O)CHCHCHCl∼ playing a decisive part. Real PVC macromolecules have been shown to contain 10−4 mole per base-mole of PVC of the latter, which are the cause of the low thermal stability. The purity of the monomer, the presence of oxygen in the reaction zone, the polymerization temperature, and other factors have been established to have a significant influence on the content of the ∼C(O)CHCHCHCl∼ groups in PVC. |
