A synthetic route to ultra-high molecular weight polystyrene (>10⁶) with narrow molecular weight distribution by emulsifier-free, emulsion organotellurium-mediated living radical polymerization (emulsion TERP)

Abstract

We propose a route to synthesizing ultra-high molecular weight (>10 6 ) polystyrene (PS) having a narrow molecular weight distribution by controlled/living radical polymerization. The process is an emulsifierfree, emulsion organotellurium-mediated living radical polymerization (emulsion TERP) using poly-(methacrylic acid)-methyltellanyl as a macro-chain transfer agent with a degenerative chain transfer (DT) mechanism. Under the polymerization conditions in which PS particles were formed by a self-assembly nucleation of polymerizing macro-chain transfer agents, very stable PS particles were successfully obtained. The segregation effect in the emulsion polymerization system can suppress the radical termination reaction, resulting in an ultra-high number-average molecular weight (M n ) PS in almost 24 h under 1 atm. The final M n value was controlled by changing the initial monomer loading (solid contents of styrene), and then PS having a M n ∼1.2 × 10 6 with a low polydispersity index (∼1.3) was successfully obtained. † Part CCCLXIII of the series "Studies on Suspension and Emulsion".

Electrically Mediated Membrane Pore Gating via Grafted Polymer Brushes

“…The large error bar associated with the 7 h time point could be a result of small differences in the reactor (e.g., mixing conditions and temperature variability), which could impact reaction rates, being magnified over the prolonged reaction period, leading to some variability in the overall molecular weight of the brushes. Although the polymer dispersity is relatively high for controlled polymerization (1.27–1.37), other studies reported similar PDI values when growing high molecular weight polymers using ATRP methods. , The very low Cu­(I) to Cu­(II) ratio targeted during the eATRP process was used to control the polymerization reaction, which minimized the dispersity of the resulting polymer brushes . The low dispersity hints at the possibility for uniformly sized pore gating that would provide a sharp MWCO for the membrane.…”

“…Although the polymer dispersity is relatively high for controlled polymerization (1.27−1.37), other studies reported similar PDI values when growing high molecular weight polymers using ATRP methods. 36,37 The very low Cu(I) to Cu(II) ratio targeted during the eATRP process was used to control the polymerization reaction, which minimized the dispersity of the resulting polymer brushes. 38 The low dispersity hints at the possibility for uniformly sized pore gating that would provide a sharp MWCO for the membrane.…”

Partitioning effect of nitrogen catalyst into polymerizing particles on dispersion reversible chain transfer catalyzed polymerization (dispersion RTCP) of methyl methacrylate in supercritical carbon dioxide and organic solvents

“…Controlled/living radical polymerization (CLRP) is a powerful approach for a precision polymer synthesis, that is, well‐defined vinyl polymers with predetermined molecular weight having narrow distribution and complex polymer architecture . To date, a wide variety of approaches of CLRP has been developed.…”

“…Therefore, the synthesis of polymer particles by radical polymerization in scCO 2 has been carried out by many groups [18][19][20][21][22][23] since pioneering work was reported by DeSimone et al 7 Controlled/living radical polymerization (CLRP) is a powerful approach for a precision polymer synthesis, that is, well-defined vinyl polymers with predetermined molecular weight having narrow distribution and complex polymer architecture. [24][25][26][27][28][29][30][31][32][33][34][35][36] To date, a wide variety of approaches of CLRP has been developed. Iodine transfer polymerization (ITP) with iodide compounds as chain transfer agents is one of well-known CLRP and has attracted much attention as a simple, robust and environmentalfriendly method without heavy metal.…”

Particle Nucleation in the Initial Stage of Emulsifier‐Free, Emulsion Organotellurium‐Mediated Living Radical Polymerization (Emulsion TERP) of Styrene: Kinetic Approach

“…[18][19][20][21][22][23][24][25][26][27][28][29][30] In our previous works, TERP was applied to the emulsion poly merization (emulsion TERP) utilizing the selfassembly technique of poly(methacrylic acid)-methyltellanyl (PMAA-TeMe) macrochain transfer agent, and we synthesized poly(n-butyl acrylate) (PBA) and polystyrene (PS) particles having moderately narrow molecular weight distributions at 60 °C with 220 rpm stirring, where the monomer was floated on the aqueous phase. [31][32][33][34][35][36][37][38][39][40][41] However, the obtained PBA and PS particles had bimodal distribution with nanometer-sized and submicrometer-sized particles. We considered that possible two particle nucleation mechanisms concurrently occurred in the emulsion TERP system: (i) self-assembly Table 1.…”