화학공학소재연구정보센터
Macromolecules, Vol.42, No.20, 7797-7810, 2009
Microkinetic Modeling of Structural Properties of Poly(vinyl chloride)
The free radical suspension polymerization of vinyl chloride is modeled at the elementary reaction level, systematically taking into account diffusion limitations. By deriving balances for structurally distinct polymer and radical species the formation of structural defects can be followed: monomer conversion, averages of the molar mass distribution and the structural defects content can be calculated as a function of polymerization time for industrially relevant conditions. A good agreement between literature reported and calculated values for these properties is obtained for a polymerization temperature range of 325-340 K, a dicetyl peroxydicarbonate and dimyristyl peroxydicarbonate initiator concentration range of 0.00069-1.0 wt %, and a monomer conversion range of 12-96%. The increase of the branching content and the decrease of the terminal double bond content at high monomer conversions can be explained in terms of a favoring of monomolecular reactions and the increasing importance of addition reactions to unsaturations at these conditions.