Emulsifier-Free Acrylate-Based Emulsion Prepared by Reverse Iodine Transfer Polymerization

Tao Huang; Qing-Xia Yuan; Shu-Ling Gong

doi:10.3390/polym12030730

Emulsifier-Free Acrylate-Based Emulsion Prepared by Reverse Iodine Transfer Polymerization

Polymers (Basel). 2020 Mar 24;12(3):730. doi: 10.3390/polym12030730.

Authors

Tao Huang¹, Qing-Xia Yuan¹, Shu-Ling Gong¹

Affiliation

¹ College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, China.

Abstract

The self-emulsifying acrylate-based emulsions with solid content 45 wt.% were prepared in 3.5 h by reverse iodine transfer polymerization (RITP), and the polymer molecular weight (M_n) could be 30,000 g·mol^-1. The influences of methacrylic acid (MAA) amount, soft/hard monomer mass ratio, and iodine amount on polymerization and latex were investigated. A moderate amount of ionized MAA was needed to stabilize the emulsion. Glass transition temperature (T_g) was decreased with the increasing mass ratio of soft/hard monomer. A higher iodine amount resulted in lower M_n. The increased M_n after chain extension of the polymer with water-insoluble monomers in iterative one-pot method proved the living of polymer. Compared with conventional emulsion polymerization, molecular weight (M_n) could be controlled, and M_n of polymer synthesized in RITP emulsion polymerization is higher; emulsion of polyacrylate-containing hydroxyl monomer units prepared by RITP emulsifier-free radical polymerization is more stable. Good properties, such as hardness, water resistance, adhesion, and increased value of maximum tensile of films modified by reaction of polyacrylate with melamine-formaldehyde (MF) resin, indicated potential application in baking coating.

Keywords: acrylate-based emulsion; controlled radical polymerization; iterative one-pot method; reverse iodine transfer polymerization; self-emulsifying.