Dynamic mechanical properties of interpenetrating polymer networks formed by UV curing processes

Two-component interpenetrating polymer networks (IPN) were made by stepwise synthesis by UV-irradiated polymerization and heat curing. The mechanical properties of normal IPN, inverse IPN and SIN (simultaneous interpenetrating networks) prepared with acrylate and epoxy were studied. Unique mechanical properties were found in each case. All of these iPN systems were composed of the individual preswollen networks. A homogeneous system is produced in the inverse IPN and SIN, while a heterogeneous system is brought about in the normal IPN. Glass transition temperatures for the inverse IPN and the SIN are lower than the normal IPN, and are attributed to molecular packing effects.