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

• Main Authors: Tao Huang, Qing-Xia Yuan, Shu-Ling Gong
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Polymers
• Subjects: self-emulsifying; acrylate-based emulsion; reverse iodine transfer polymerization; controlled radical polymerization; iterative one-pot method
• Online Access: https://www.mdpi.com/2073-4360/12/3/730

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 (<i>M</i>_n) could be 30,000 g&#183;mol^&#8722;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 (<i>T</i>_g) was decreased with the increasing mass ratio of soft/hard monomer. A higher iodine amount resulted in lower <i>M</i>_n. The increased <i>M</i>_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 (<i>M</i>_n) could be controlled, and <i>M</i>_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&#8722;formaldehyde (MF) resin, indicated potential application in baking coating.