Synthesis of micrometer-sized poly(vinyl acetate) particles through microsuspension iodine transfer polymerization: effect of iodine species in a water medium

Abstract

Microsuspension iodine transfer polymerization (ms ITP) of vinyl acetate (VAc) was demonstrated for the first time with the evidence of simulation of the polymerization rate in the aqueous phase (Rpw)....

Iodine-influenced morphological evolution of micrometer-sized poly(methyl methacrylate)-block-poly(vinyl acetate) particles upon hydrolysis

“…This is a consequence of the electrostatic force offered by iodic ions. As revealed in a previous work, 12 the PVAc particles prepared by ms ITP had a higher absolute ζ potential (−14.02 mV) than the PVAc particles prepared by ms CRP (−4.67 mV), leading to high colloidal stability. In this work, although the direct proof of iodic ions could not be given after sms ITP, the comparison of pH before and after sms ITP can show the difference since the hydrogen ions in this step primarily stem from the side reaction (Fig.…”

“…Micrometer-sized PMMA-b-PVAc particles Previously, micrometer-sized PVAc and PMMA particles were separately synthesized without the generation of submicrometer-sized particles using ms ITP by us 12 and Chaiyasat et al, 20 respectively. It shows the high feasibility of the synthesis of micrometer-sized PMMA-b-PVAc particles by ITP in a microsuspension system.…”

“…structures. In the previous work, 12 the crosslinking of PVA was discussed concretely. At a high temperature, the hydroxyl groups of PVA are oxidized by iodine radicals into ketone and aldehyde specimens (Fig.…”

“…10,11 Therefore, the synthesis of PVAc with controlled M n and M w / M n is of great importance for the development of its derivatives. In our previous work, 12 the controlled PVAc was successfully synthesized by microsuspension iodine transfer polymerization ( ms ITP) using iodoform (CHI 3 ) as the chain transfer agent to not only meet the above demands but also obtain micrometer-sized particles. The latter aim is usually regarded as the difficulty of hydrophilic monomers in a conventional suspension or microsuspension system, which is accompanied by submicrometer-sized particles since the homogenous nucleation in the aqueous phase is difficult to be restrained.…”

Emerging Concepts in Iodine Transfer Polymerization

“…[ 48 ] ITP of vinyl acetate, a challenging monomer for radical polymerization, was attempted in microsuspension system using iodoform as CTA. [ 49 ] Using high temperatures for polymerization led to undesired hydrolysis of poly(vinyl acetate), thus the 2,2′‐azobis(4‐methoxy‐2.4‐dimethyl valeronitrile) (V‐70) initiator at 30 °C was employed for optimum polymerization condition. Average particle size was 22.3 µm with Đ : 2.0 and a molecular weight of 26 000 g mol −1 was obtained.…”