The modifications of properties of some semi-interpenetrating polymer networks based on
aromatic polyurethane and a crosslinked epoxy resin, during UV irradiation with a mercury
lamp (λ> 300 nm), were investigated. Variation of some properties, such as colour, gloss,
contact angle, mass variations and water retention were monitored according to the
irradiation time. Photochemical reactions that occurred during irradiation were monitored by
FT-IR. The results demonstrated that polyurethane-epoxy resin semi-interpenetrating …

The behavior of two semi-interpenetrating polymer networks (S-IPNs) based on
polyurethane (PU) and epoxy maleate of bisphenol A (EMBA) under exposure to UV
radiation for long period of times (up to 200h) was investigated. The networks obtained by
the specific mixture under certain thermal treatment included in their structures crosslinked
EMBA and linear PU. Advanced photooxidative degradation took place for long time of UV
irradiation (over 160h, especially), with almost a total destruction of the raw structures. The …