Well-Controlled Emulsion Polymerization of Methyl Methacrylate Using (Hg,Cd)-Diphenylcarbazone Catalysts: An attempt to Create Hg-free, Nontoxic, γ-Radiation and thermal Stable Films

In this work, a procedure for synthesis of Hg and Cd-free PMMA films via emulsion polymerization using different concentrations (0.000025 - 0.00025 g mol/L) of Hg and Cd-diphenylcarbazone complexes (Hg(or Cd)DPC) as a catalytic chain transferring agent was reported. The extraction of either HgDPC or CdDPC from resultants polymers was confirmed using UV-Vis spectrophotometry and the neat polymers presented no cytotoxicity to human Hep G2 Cells. Well dispersity of PMMA (DPI of ca. 1.3) and the optimal performance in MMA polymerization was achieved using 0.00020 g mol/L HgDPC, which exhibited a PMMA yield of ca. 98%. Thermal behavior studies proved that PMMA films became highly thermally stable suggested as due to the elimination of head-to-head growing PMMA chains and disproportionation mechanistic steps. Therefore, the degradation process is mainly due to the random main chain scission, which on turn demonstrated a positive impact on its melting, decomposition and, glass transition (Tg) temperatures where, Tg of PMMA samples understudy increased in the following order: blank(60°C)˂CdDPC(69°C)˂HgDPC(84°C).The radiation shields and mechanical properties of PMMA films were also studied to evaluate the anti-radiation affinity of these complexes where, a tensile strength of 85.0 MPa of resultant PMMA using HgDPC was acquired.

Half-sandwich rare-earth metal complexes bearing a C5Me4-C6H4-o-CH2NMe2 ligand: synthesis, characterization and catalytic properties for isoprene, 1-hexene and MMA polymerization

New rare-earth metal complexes bearing the ligand C5Me4-C6H4-o-CH2NMe2 were synthesized and studied as precatalysts for isoprene, 1-hexene and MMA polymerization.

Bromoalkyl ATRP initiator activation by inorganic salts: experiments and computations

The bromoalkyl ATRP initiator EBrPA is activated by many alkali, alkaline-earth and ammonium salts, leading to MMA polymerization, but only the iodides yield a controlled process because of a degenerative transfer mechanism contribution.

Modeling of Methyl Methacrylate Polymerization Using MATLAB

This paper presents a modeling of methyl methacrylate (MMA) polymerization with toluene in the presence of azo-bi’s-isobutyronitrile (AIBN) using MATLAB. This work aims to optimize the initial concentration of initiator and the reactor temperature to achieve a maximum monomer conversion in minimum batch time. The optimization of solution polymerization of MMA based on the three-stage polymerization model (TSPM) was performed using ode23t solver. The non-linear polymerization kinetics considered the gel, glass and cage effect to obtain a realistic prediction. The predicted reactor and jacket temperature showed a reasonable agreement with the experimental data, where the error is about 2.7 % and 2.3 %, respectively. The results showed that a maximum monomer conversion of 94 % was achieved at 0.126 kgmol m–3 of the initial concentration of AIBN and 346 K of the initial reactor temperature in 8,951 s (2.5 h).