Statistical and mathematical strategies are applied in several areas for new product development.1-3 In the chemical industry, these approaches are recommended and mainly used for evaluating the variables’ effects in a given system and for optimizing the manufacturing processes.4-7 Several examples that employ statistical tools can be found in the literature: multivariate calibration, pattern recognition and design of experiments (DOE).8-13 DOE has been used to organize the data set results from evaluation experiments and to obtain the maximum amount of information from a reduced number of experiments,14,15 mainly when fractional factorial designs are performed.16,17
Factorial design combines the use of mathematical and statistical knowledge to obtain information about a given system,18 and in chemistry this discipline is named chemometry.19 Lu et al.,20 for instance, used full factorial design to study a film-coated photoreactor, and three variables were investigated. Dickens21 used DOE to study the performance of epoxy coating system using an accelerated test laboratory. In polymer system studies, Sáenz and Asua22 investigated five variables using two-level fractional factorial design to identify the region of experimental conditions in which monodispersed latexes could be prepared. Mishra et al.,23 also using a fractional factorial design, verified the effects of six variables in the semi-continuous emulsion polymerization of methyl methacrylate. Lucchesi et al.24 investigated 10 variables using fractional factorial design to study suspension polymerization of styrene, divinylbenzene, and N-(p-vinylbenzyl)-4,4-dimethylazlactone.