Polymerization of Vinyl Chloride at Ambient Temperature Using Macromolecular Design via the Interchange of Xanthate: Kinetic and Computational Studies

Abstract

Reversible deactivation radical polymerization of vinyl chloride (VC) by methyl (ethoxycarbonothioyl)­sulfanyl acetate (MEA)-mediated macromolecular design via the interchange of xanthate (MADIX) polymerization at ambient temperature is reported. The polymerization system was studied using two conventional radical initiators (having very distinct half-life times at room temperature). The system was optimized regarding the nature of the solvent, the monomer concentration, the polymerization temperature, and the target molecular weight. The kinetic data showed linear first-order kinetics, the linear evolution of molecular weights with conversion, and polymers with narrow molecular weight distributions (Đ ≈ 1.2 to 1.3) using a low temperature (30–42 °C) and cyclopentyl methyl ether (CPME) as a “green” solvent. The resulting MEA-terminated poly­(vinyl chloride) (PVC) was fully characterized by 1H nuclear magnetic resonance spectroscopy that revealed the existence of a very small fraction of structural defects and the presence of chain-end functional groups. “One-pot” chain extension (with VC) and “one-pot” block copolymerizations (with vinyl acetate − VAc and N-vinylcaprolactam − NVCL) experiments confirmed the “livingness” of the MEA-terminated PVC chains, giving access to different PVC-based block copolymers. Computational studies confirm the results of the solvent screen and suggest that changes to the initial MADIX leaving or stabilizing groups could improve control. The computational data were further confirmed using methyl 2-(4-methoxyphenoxycarbonothioylthio)­acetate. This work establishes a new green route to afford a wide range of new complex macrostructures including high-value materials based on PVC segments.

“All-PVC” Flexible Poly(vinyl Chloride): Nonmigratory Star-Poly(vinyl Chloride) as Plasticizers for PVC by RAFT Polymerization

“…Various xanthate and dithiocarbamate RAFT agents have been reported to be effective in mediating RAFT polymerization of less activated monomers and also provide good control over RAFT polymerization of VC to form linear PVC. ,− Multi-xanthates similar to RAFT-3 and RAFT-4 have previously been used in synthesis of low dispersity star -PVAc . Thus, we chose to use these RAFT agents in the synthesis of star -PVC.…”

Efficient internal plasticization of poly(vinyl chloride) via free radical copolymerization of vinyl chloride with an acrylate bearing a triazole phthalate mimic

“…After establishing the temperature, the influence of the solvent was addressed. Because PVC is very insoluble in its own monomer, as well as in most common organic solvents, DMSO [28,30,[49][50][51] and cyclopentyl methyl ether (CPME) [27,52,53] were tested (Table 1, entries 3 and 6). While DMSO is a commonly utilized organic solvent for VC polymerization, CPME has emerged as a green alternative, due to its high hydrophobicity, relative stability under both acidic and basic conditions, and low tendency to form dangerous peroxide by-products [54].…”

“…However, several adjustments are needed for industrial application: specifically the use of less expensive compounds (e.g. halogen based initiators, catalyst) and faster polymerization rates [27][28][29][30][31][32]. At this time, traditional FRP is the only affordable method for the synthesis of PVC at an industrial scale [2,33].…”

Iodine‐Transfer Polymerization (ITP) of Ethylene and Copolymerization with Vinyl Acetate

“…After more than twenty‐five years of research and developments, a myriad of new polymer architectures and properties have been achieved. However, the RDRP of some monomers, sometimes of major industrial importance, remains challenging. Among them is ethylene, which leads to polyethylene (PE), the most widely produced polymer in the world.…”