Mn_2Al-LDH- and Co_2Al-LDH-stearate as photodegradants for LDPE film

摘要

The layered double hydroxides (LDH) Mn_2Al-LDH-stearate and Co_2Al-LDH-stearate were prepared by a surfactant-assisted intercalation of the corresponding precursor LDH-CO_3 forms. These compounds were evaluated as potential photodegradant additives in low density polyethylene films with a thickness of ca. 40 μm. They were incorporated into blown polyethylene films via a 10% masterbatch. The films were subjected to accelerated ageing in a QUV weatherometer. The machine was fitted with A320 lamps and operated on a dry cycle at 63 ℃ and an irradiance of 0.67 W/m~2. It was found that 100 h of QUV exposure was sufficient to cause mechanical embrittlement of films containing as little as 0.1% of either active additive.