Premium
Distribution of volatile species in a refluxing polymer colloid
Author(s) -
Zollars Richard L.,
Chen CheinTai,
Jones D. Adrian
Publication year - 1988
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690340504
Subject(s) - polymer , branching (polymer chemistry) , aqueous solution , monomer , polymerization , molar mass distribution , colloid , emulsion polymerization , thermodynamics , vapor pressure , volume (thermodynamics) , aqueous two phase system , phase (matter) , vinyl acetate , chemical engineering , partition coefficient , materials science , polymer chemistry , chemistry , chromatography , organic chemistry , copolymer , physics , engineering
Monomer partitioning between the aqueous and polymer phases in a latex determines many properties of an emulsion polymerization, such as the reaction rate, molecular weight development and, if operated under refluxing conditions, the reaction temperature. A unique two‐chamber vapor‐liquid equilibrium cell was used during this investigation to obtain an in situ separation of the aqueous phase from the latex, thus permitting a direct determination of the compositions of the aqueous, polymer, and vapor phases in a latex, even under refluxing conditions. Thermodynamic analysis of the vapor‐liquid equilibrium problem allows the prediction of the composition of all phases from measured values of the temperature and pressure only. These predictions agreed well with data from other investigations under nonrefluxing conditions and with the aqueous and vapor phase compositions from this investigation. The polymer phase composition data for vinyl acetate polymers with average molecular weights in excess of 10 6 showed consistently higher polymer volume fractions than predicted. This latter result may be due to crosslinking or strong entanglements resulting from increased chain branching at these high molecular weights.