STABILITY STUDY ON POLYPROPYLENE NANOCOMPOSITES

摘要

Considering the continuing high interest and potential of polymer nanocomposites, insight into their process and long-term thermal stability is an important prerequisite to commercialisation of these materials. When considering organically modified layered silicates in particular, there are some drawbacks expected due to one or more of the following; the lower thermal stability of the surface treatment chemicals used at standard polymer processing conditions, metal impurities in the natural organoclays, the presence of free maleic anhydride in maleic anhydride grafted polymers used as compatibilisers for polyolefins, and the oligomeric nature of these compatibilisers. Solving the stability issues of nanocomposites forms an important sub-class within the many ongoing R&D activities in this area. The use of more thermally stable surfactants, alternative compatibilisers, and more pure layered silicates are some of the topics studied.rnWe have conducted a study to investigate stability performance of PP nanocomposites with multiple extrusion, long-term thermal ageing, and Oxygen Induction Time (OIT) tests. The study showed that a nanocomposite formulation was comparable to neat PP in multiple extrusion testing and thus in process stability. However, long-term thermal ageing was considerably inferior to that of neat PP. Further studies will be undertaken to identify the significance of the possible factors as mentioned above, influencing nanocomposite stability.