Functional Acrylic Resins Prepared via Photo-Induced Telomerization Using Tetrabromomethane as Telogen

Area of Science:

• Polymer Chemistry
• Materials Science
• Organic Synthesis

Background:

• Functional acrylic resins (FARs) are versatile materials with applications in coatings, adhesives, and advanced composites.
• Developing efficient methods for in-chain functionalization and controlled molecular weight is crucial for tailoring FAR properties.
• Incorporating specific functional groups like carboxyl and benzophenone, along with terminal bromine atoms, enhances resin reactivity and performance.

Purpose of the Study:

• To develop and verify a novel, solution-free UV-initiated telomerization method for synthesizing functional acrylic resins (FARs).
• To investigate the impact of tetrabromomethane (CBr4) telogen content on the kinetics, molecular weight, and thermal properties of the synthesized FARs.
• To confirm the successful incorporation of carboxyl, benzophenone groups, and terminal bromine atoms into the acrylic telomer structure.

Main Methods:

• Solution-free UV-initiated telomerization using n-butyl acrylate, acrylic acid, and 4-acrylooxybenzophenone.
• Utilized tetrabromomethane (CBr4) as a telogen at varying concentrations.
• Employed photo-differential scanning calorimetry (photo-DSC) for kinetic studies, gel permeation chromatography (GPC) for molecular weight analysis, and differential scanning calorimetry (DSC) for thermal properties (Tg).
• Nuclear magnetic resonance (NMR) spectroscopy was used for structural confirmation.

Main Results:

• A telogen content exceeding 5 wt. parts did not significantly alter UV-telomerization rates, molecular weights, or glass transition temperatures (Tg).
• Increased tetrabromomethane content significantly enhanced monomer conversion, reaching up to 88%.
• Higher telogen concentrations effectively reduced the viscosity of the functional acrylic resins to approximately 6 Pa·s.
• NMR studies confirmed the successful incorporation of CBr4 into the functional acrylic telomer structure.

Conclusions:

• The developed UV-initiated telomerization offers an efficient route to functional acrylic resins with desirable in-chain and terminal functionalities.
• Tetrabromomethane content can be optimized to control monomer conversion and resin viscosity without compromising essential material properties.
• This method provides a pathway for producing tailored functional acrylic resins for advanced material applications.