Experiment‐design methods in innovative polymer material planning

In the work, the design of experiments (DOE) method was used to obtain a modified epoxy resin of reduced fragility. As modifiers of commercial epoxy resin, urethane prepolymers with isocyanate terminal groups were used. Experimental points (samples of specified composition of resin prepolymer and a curing agent) were generated by the STATISTICA program module Design of Experiments using a central composition design. A study of the mechanical properties of modified resin samples was carried out for five intermediate values of input variables x1 (resin/hardener ratio) and x2 (modifier, wt %), designated for the normalized values 0, ± 1, and ±1.414. The STATISTICA algorithms analyzing the results of the practical implementation of the planned experiments allowed us to develop a model describing the dependence of the mechanical properties of composite resins on the composition and then to select the optimal compositions of epoxy resin for their practical applications.