MSE PhD Defense - Abhiram Kannan

June 29, 2015; Monday at 2 p.m.

Location: Love building, room 295

Committee:    

Dr. David Bucknall (MSE) (advisor)

Dr. Donggang Yao (MSE)

Dr. Meisha Shofner (MSE)

Dr. Kyriaki Kalaitzidou (ME)

Dr. Aaron P. Eberle (ExxonMobil Research and Engineering)

Title: Structure - Property Relationships in Polyethylene Blown Films

Abstract:

As the title of this thesis suggests, the contents of this dissertation aim to provide insight into the relationships between the structure and properties of blown films of polyethylene. The fabrication of blown films is a complex industrial process that received some attention in the past from both industry and academia with the view to establish detailed property-structure-processing linkages between polymers and their resulting blown films. Unfortunately a clear understanding of those variables which control properties essential to the end application of blown films, specifically the resistance to tear and puncture are not fully developed. The current work uses powerful synchrotron based X-ray scattering to explore the morphologies as well as morphology evolution under strain, for a series of polyethylenes whose architectures are well understood. In order to relate morphology to molecular architecture via scattering measurements, a number of analysis protocols have been developed which help quantify both the crystalline and non crystalline components of the overall semicrystalline morphology. The quantification itself is provided in terms of dimensionality and orientation based parameters of the morphology. Our findings indicate that the tear and puncture resistance of films correlate with these extracted parameters.

Additionally we are able to relate some of the parameters to the molecular architectures of the polyethylenes under investigation. Thus we have begun to elucidate those aspects of the molecular architecture of polyethylene, the targeted manipulation of which result in attainment of desired tear and puncture properties in blown films.