Date of Award

Fall 12-2014

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Polymers and High Performance Materials

Committee Chair

Jeffrey S. Wiggins

Committee Chair Department

Polymers and High Performance Materials

Committee Member 2

Gary V. Krebs

Committee Member 2 Department

Kinesiology

Committee Member 3

Sarah E. Morgan

Committee Member 3 Department

Polymers and High Performance Materials

Committee Member 4

Derek L. Patton

Committee Member 4 Department

Polymers and High Performance Materials

Committee Member 5

Robson F. Storey

Committee Member 5 Department

Polymers and High Performance Materials

Abstract

Twin screw extruders can be used as continuous polymer reactors to process polymers, which are conventionally made through batch reactors. Batch processes have certain undesirable qualities such as improper mixing and the inability to precisely control the reaction, which leads to variation between batches and potential exotherms. The work presented in this dissertation investigates the use of continuous polymer reactor designs to efficiently process renewable sourced thermoplastic polyurethanes (TPU), and prepreg epoxy matrix prepolymers.

The overall goal of this research is to highlight the modularity of twin screw extruders as continuous polymer reactors to synthesize the relevant polymers. Chapter I defines the specific goals that pertain to this research. Chapter II provides a brief overview of extruders and reaction extrusion. Different types of extruders are briefly reviewed, but the focus is on intermeshing co-rotating twin screw extruders, which are ideal for use as continuous polymer reactors. The chapter also discusses reaction extrusion and the advantages it offers over batch reaction.

The next two chapters delve into the core of the research. Chapter III presents a continuous polymer reactor design for renewable sourced Cerenol based TPUs. TPUs comprised of polyol soft-blocks of renewable sourced polytrimethylene ether glycol, Cerenol, were compared with TPUs comprised of polyol soft-blocks of polytetramethylene ether glycol (PTMEG). Cerenol and PTMEG based TPUs were successfully processed via reaction extrusion utilizing nearly identical process conditions. Chapter IV presents lab-scale and industrial-scaled up continuous polymer reactor designs for synthesizing and partially curing two commercially used prepolymers, 8281 and 5208. Both of these prepolymers are widely used in the aerospace industry.

The final chapter, Chapter V, provides recommendations for future work. Overall, three continuous polymer reactor designs were successfully invented to formulate three different polymers. The modularity and modification of a single twin screw extruder can be used to synthesize different polymers in a continuous process.

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