Effect of Aging on Film Strength and Morphology of Natural Additive Polypropylene Packaging Film

At present, plastics packaging had used synthetic degradable additives for conventional non degradable polyolefins. Faster degradation of polyethylene (PE) and polypropylene (PP) through oxidation process by employing commercialised metal complex had been established. Use of natural additives is more environmentally friendly and nontoxic if leached and is safe for use as films in food packaging. Additives such as natural oil and pigment can be compounded as natural additives for polypropylene (PP). In this study, oil with various composition of dione were incorporated into PP and compounded before film casting. Tensile properties of natural additives filled PP film was studied upon different aging condition and characterizations made. For all samples, upon high humidity, heat and photoaging, tensile strength, were found to be reduced and higher modulus were found which indicated that film were brittle and fragmented upon degradation. Film exposure resulted in very low strength and fragmented brittle film which are found to be degraded faster when both amount of oil/dione and higher composition of dione were employed. Morpholoy of the degraded films were being analysed with FESEM microscopy and Atomic Force Microscopy (AFM). From morphological and tensile testing performed, it was found that degradation has occurred when sample had been exposed for two weeks in the humidity chamber with the addition of oil and dione for PP compound. From surface morphology AFM analysis, it was also shown that surface erosion had occurred and a high surface roughness value was exhibited. Degradation had proceeded at faster rate upon use combination of oil and dione whereby lowest strength were imparted after been exposed for 2 weeks.