It is believed that nanosize particle fillers can improve polymers’ properties because of their particular characteristics. Although the mechanism of reinforcement is controversial, it is commonly accepted that the filler morphology is a critical factor. To further understand the reinforcement mechanism, different nanosize silica were used to investigate the relationship between filler morphology and reinforcement. Ultra small angle x-ray scattering (USAXS) was used to study the morphology of nanosize silica. The viscosity is used to study the interactions between fillers and matrix.
In Chapter 1, current theories and models to interpret the reinforcement mechanism are introduced. The goals of this thesis are proposed based on the discussions of current theories.
In Chapter 2, the morphology study of silica filler is presented. Several types of silica are used in this study to find out the factors affecting the filler morphology. Based on the morphology study, it is straightforward to choose appropriate silica samples to further study the relationship between filler morphology and properties.
In Chapter 3, the rheology properties of chosen silica samples are reported.
In Chapter 4, tensile experiments of chosen silica samples are reported; the effects of silica fillers on polymer’s modulus and breakage elongation are explored.
In Chapter 5, conclusions are presented.