The starch nanocrystal filled biodegradable poly(ε-caprolactone) composite membrane with highly improved properties

The platelet-like starch nanocrystal (SNC) particles were used to prepare composite membrane with biodegradable poly(ε-caprolactone) (PCL) for the potential packaging membrane application. The presence of SNC particles improves gas barrier properties, tearing strength, as well as the creep resistance of the PCL membrane evidently at the lower loading levels. This improvement effect can be further enhanced by the surface acetylation of SNC. The presence of acetylated SNC particles (1wt%) can reduce the oxygen transmission rate by about 70% and increase the tearing strength by about 68%, which is due to the improved phase adhesion. The strain failure stage of the membrane is also highly delayed in the presence of acetylated SNC, from hour-time scale to day-time one. Therefore, the biodegradable SNC is a promising candidate to be used as the filler to improve the key properties of biodegradable PCL membrane, but the chemically modified SNC is the better option.