Bubble-Free Frontal Polymerization of Acrylates via Redox-Initiated Free Radical Polymerization

Area of Science:

• Polymer Chemistry
• Materials Science
• Chemical Engineering

Background:

• Thermal frontal polymerization (FP) using peroxide initiators often results in bubble formation.
• Bubbles in FP limit the practical applications of acrylate polymers.
• Redox initiators offer a potential solution by preventing gaseous byproducts and lowering front temperatures.

Purpose of the Study:

• To investigate bubble-free frontal polymerization of acrylate monomers using a redox initiation system.
• To compare the performance of redox initiation with conventional peroxide initiation in acrylate FP.
• To evaluate the impact of monomer functionality on FP behavior with redox initiators.

Main Methods:

• Investigated frontal polymerization (FP) of methyl methacrylate (MMA), 1,6-hexanediol diacrylate (HDDA), and trimethylolpropane triacrylate (TMPTA).
• Utilized an N,N-dimethylaniline/benzoyl peroxide (DMA/BPO) redox couple at room temperature.
• Compared front behavior, pot life, and bubble formation against systems using Luperox 231 (peroxide initiator).

Main Results:

• Redox initiation enabled bubble-free frontal polymerization of various acrylate monomers.
• Lower front temperatures and controlled pot life were observed with the redox system.
• Monomer functionality influenced the FP characteristics under redox initiation.

Conclusions:

• Redox initiation is a viable strategy for bubble-free frontal polymerization of acrylates.
• This method offers advantages for rapid, energy-efficient manufacturing of polyacrylates.
• Potential applications include advanced manufacturing techniques like 3D printing and composite fabrication.