The influence of N-vinyl pyrrolidone on polymerization kinetics and thermo-mechanical properties of crosslinked acrylate polymers

• Published in: Journal of polymer science. Part A, Polymer chemistry Vol. 45; no. 17; pp. 4062 - 4073
• Main Authors: White, Timothy J., Liechty, William B., Guymon, C. Allan
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-09-2007; Wiley
• Subjects: Applied sciences; Copolymerization; Exact sciences and technology; kinetics (polym); Organic polymers; photopolymerization; Physicochemistry of polymers; Preparation, kinetics, thermodynamics, mechanism and catalysts; thermal properties; Acrylic acid ester; Elastic modulus; photopolymerization; Polyfunctional compound; Mechanical properties; Mass copolymerization; Composition effect; Experimental study; Reaction rate; Chemical reaction kinetics; Crosslinked copolymer; Dynamic mechanical properties; thermal properties; Pyrrolidone(vinyl) copolymer; kinetics (polym); Acrylate copolymer; Monomer; Chemical reactivity; Comparative study; Photochemical copolymerization
• ISSN: 0887-624X; 1099-0518
• DOI: 10.1002/pola.22173

Polymerization of multifunctional acrylate monomers generates crosslinked polymers that are noted for their mechanical strength, thermal stability, and chemical resistance. A common reactive diluent to photopolymerizable formulations is N‐vinyl pyrrolidone (NVP), which is known to reduce the inhibition of free radical photopolymerization by atmospheric oxygen. In this work, the copolymerization behavior of NVP was examined in acrylate monomers with two to five functional groups. At concentrations as low as 2 wt %, NVP increases the polymerization rate in copolymerization with multifunctional acrylate monomer. The relative rate enhancement associated with adding NVP increases dramatically as the number of acrylate double bonds changes from two to five. The influence of NVP on polymerization kinetics is related to synergistic cross‐propagation between NVP and acrylate monomer, which becomes increasingly favorable with diffusion limitations. This synergy extends bimolecular termination into higher double bond conversion through reaction diffusion controlled termination. Copolymerizing concentrations of 5–30 DB% NVP with diacrylate or pentaacrylate monomer also increases Young's modulus and the glass transition temperature (Tg) in comparison to neat acrylate polymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4062–4073, 2007
A common reactive diluent to photopolymerizable formulations is N‐vinyl pyrrolidone (NVP) which is known to reduce the inhibition of free radical photopolymerization by atmospheric oxygen. In this work, the copolymerization behavior of NVP is examined in mixtures with acrylate monomers with two to five functional groups. The copolymerization behavior of NVP/acrylate systems is dependent on monomer functionality. The diffusional constraints in high functionality acrylate polymerization differentiate the impact of NVP on polymerization rate, double bond conversion, and reaction diffusion controlled termination. The effects of NVP on polymerization behavior are also correlated to characterization of thermo‐mechanical properties of NVP/acrylate copolymers.