Simulation of reversible chain transfer catalyzed polymerization (RTCP): effect of different iodide based catalysts

• Published in: Journal of polymer research 2012-03, Vol.19 (3), p.1-9, Article 9740
• Main Authors: Mahjub, Alireza, Mohammadi, Hadi, Salami-Kalajahi, Mehdi, Angaji, Mahmood Torabi
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts; Chain transfer; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Computer simulation; Depletion; Industrial Chemistry/Chemical Engineering; Molecular weight; Monte Carlo methods; Original Paper; Polymer Sciences; Polymerization
• ISSN: 1022-9760; 1572-8935
• DOI: 10.1007/s10965-011-9740-1

Monte Carlo kinetic simulation method was performed to study the reversible chain transfer catalyzed polymerization (RTCP) of styrene in 80°C. The effect of different iodide based catalysts (AI) was investigated on RTCP systems by simulating the chain length distribution, the depletion rate of polymerization ingredients, average molecular weights and the monomer conversion. In RTCP systems a narrow distribution was obtained compared to iodide-mediated polymerization. Superior reversible chain transfer reaction constants (k a and k da ) led to a more uniform chain length distribution and a faster PDI decrement. In each RTCP system k da /k a ratio, designates the concentration of A* by dictating the dominant side of exchange equilibriums which specifies the number of cross-termination reactions. Addition of cross-termination reactions to the iodide-mediated polymerization system decreases the number of combination reactions leading to lower average molecular weights. Higher k da /k a ratios also consequences in faster catalyst depletions and lessen monomer conversions. On the other hand, PhE-I was found to deplete rapidly in RTCP systems, changing the nonlinear increase of the number average molecular weight to a linear pattern. The Monte Carlo simulation results were in a fine agreement with experimental data which were obtained from different RTCP systems.