The Effect of the Mixtures of Photoinitiators in Polymerization Efficiencies

Author(s)

Neumann, Miguel G. ^[1] ; Schmitt, Carla C. ^[1] ; Horn, Jr., Marco A. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Journal of Applied Polymer Science; v. 112, n. 1, p. 129-134, APR 5 2009.
• Web of Science Citations: 11

Abstract

The photoinitiated polymerization of methyl methacrylate using the mixtures of camphorquinone (CQ) and acylphosphine oxides (monoacylphosphine oxide, MAPO or bisacylphosphine oxide,BAPO) was studied to determine the possible synergistic effects. The addition of the acylphosphines to CQ resulted in an increase of the polymerization rate compared with CQ alone. On the other hand, a significant decrease of the polymerization quantum yield is observed for the mixtures compared with the pure acylphosphines. Therefore, the increase in the polymerization efficiency of the two rnixtures studied, MAPO/CQ and BAPO/CQ (compared with CQ) can be traced to the larger light absorption range, rather than to the onset of new mechanisms. The presence of the coinitiator ethyl 4-dimethylaminobenzoate, EDB, always present in CQ formulations, has no effect at all on the rates of polymerization photoinitiated by the acylphosphine oxides. From the point of view of photopolymerization quantum yields, an antagonistic effect is observed because Of the energy transfer of the M more efficient initiator (MAPO or BAPO) to the less efficient one (CQ). (C) 2008 Wiley Periodicals, Inc. j Appl Polym Sci 112: 129-134, 2009 (AU)

• FAPESP's process: 03/07770-4 - Interactions of visible light with polymers: photopolymerization and photodegradation
• Grantee: Miguel Guillermo Neumann
• Support Opportunities: Research Projects - Thematic Grants