Time-intensity superposition for photoinitiated polymerization of fluorinated and hyperbranched acrylate nanocomposites

• Published in: Polymer (Guilford) Vol. 51; no. 2; pp. 334 - 341
• Main Authors: Dalle Vacche, Sara, Geiser, Valérie, Leterrier, Yves, Månson, Jan-Anders E.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2010; Elsevier
• Subjects: Applied sciences; Exact sciences and technology; Kinetics; Master curves (time-intensity superposition); Photopolymerization; Physicochemistry of polymers; Polymerization; Polymers and radiations; Photopolymerization; Master curves (time-intensity superposition); Kinetics; Branched polymer; Bulk polymerization; superposition; Fluorine containing polymer; Master curves (time-intensity; Ether polymer; Experimental study; Modeling; Silica; Chemical reaction kinetics; Luminous intensity; Kinetic model; Hyperbranched polymer; Acrylate polymer; Linear polymer; Crosslinked polymer; Nanocomposite; Prepolymer; Alkyl acrylate polymer
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2009.11.071

The validity of the time-intensity superposition principle for the photoinitiated polymerization of nanocomposites based on a monofunctional fluorinated acrylate and on a multifunctional hyperbranched polyether acrylate was investigated in this work. Master curves were obtained for the conversion as a function of time, measured by photo differential scanning calorimetry, by shifting on the time axis the curves obtained at different intensities. A power-law dependence of the shift factor on the intensity was found for all materials, with exponents equal to 0.45 ± 0.03 for the fluorinated acrylates and to 0.71 ± 0.05 for the hyperbranched polyether acrylates. Consequently it is inferred that the radiant exposure reciprocity law, implying linear dependence of the shift factor on intensity, does not apply to the studied compositions. The kinetics of the photopolymerization of materials based on the fluorinated acrylate was analyzed with the autocatalytic model. The final conversion was independent on intensity and filler content. The rate constants showed for all materials a power-law dependency on intensity, with exponents similar to those of the corresponding shift factors. [Display omitted]