Processing-structure-property relationships in solid-state shear pulverization: Parametric study of specific energy

Solid-state shear pulverization (SSSP) is a unique processing technique for mechanochemical modification of polymers, compatibilization of polymer blends, and exfoliation and dispersion of fillers in polymer nanocomposites. A systematic parametric study of the SSSP technique is conducted to elucidate the detailed mechanism of the process and establish the basis for a range of current and future operation scenarios. Using neat, single component polypropylene (PP) as the model material, we varied machine type, screw design, and feed rate to achieve a range of shear and compression applied to the material, which can be quantified through specific energy input (Ep). As a universal processing variable, Ep reflects the level of chain scission occurring in the material, which correlates well to the extent of the physical property changes of the processed PP. Additionally, we compared the operating cost estimates of SSSP and conventional twin screw extrusion to determine the practical viability of SSSP.

Processing-Structure-Property Relationships in Solid-State Shear Pulverization: Parametric Study of specific energy

Solid-state shear pulverization (SSSP) is a unique processing technique for mechanochemical modification of polymers, compatibilization of polymer blends, and exfoliation and dispersion of fillers in polymer nanocomposites. A systematic parametric study of the SSSP technique is conducted to elucidate the detailed mechanism of the process and establish the basis for a range of current and future operation scenarios. Using neat, single component polypropylene (PP) as the model material, we varied machine type, screw design, and feed rate to achieve a range of shear and compression applied to the material, which can be quantified through specific energy input (Ep). As a universal processing variable, Ep reflects the level of chain scission occurring in the material, which correlates well to the extent of the physical property changes of the processed PP. Additionally, we compared the operating cost estimates of SSSP and conventional twin screw extrusion to determine the practical viability of SSSP.

The Resonance of Beauty

Beauty is a central concern in the works of two modern American poets, Elizabeth Bishop and Richard Wilbur. Both poets have formal styles with emphases on descriptive imagery and natural tropes. While these two poets have often been studied individually in their own right, they have not previously been studied together with the particular focus on beauty. So, in my thesis, through close study of many of their works, I draw out their understandings of beauty and discuss how they relate to each other and to their audience. Iprimarily utilize their most extensive collections, which are Bishop’s The Complete Poems: 1927-1979 and Wilbur’s Collected Poems:1943 - 2004. I also drew from other less anthologized sources and prose work. In my first chapter, I examine Bishop’s work closely, and in my second chapter I analyze Wilbur’s poetry. I conclude that the concept of beauty is similarly important for both poets, but motivates them to different levels of action and commitment,Bishop’s understanding of life being less spiritual than Wilbur’s. I introduce the possibility that beauty represents a positive reality that may prove more inspiring and victorious than the pain and hardship encountered throughout human life.