Interpenetrating polymer network

[10][11] The first known IPN was a combination of phenol-formaldehyde resin with vulcanized natural rubber made by Jonas Aylsworth in 1914.

[13] Molecular intermixing tends to broaden the glass transition regions of some IPN materials compared to their component polymers.

This unique characteristic provides excellent mechanical damping properties over a wide range of temperatures and frequencies due to a relatively constant and high phase angle.

[15] On the other hand, when the glassy polymer forms a bicontinuous phase within the rubbery network, the IPN material can behave like an impact-resistant plastic.

[12] Furthermore, IPNs are often able to maintain these complex morphologies over long periods of time compared to what could be achieved by simple polymer blends.

[14] More recent applications and areas of research for IPNs include uses in drug delivery systems, energy storage materials, and tissue engineering.