Date: April 30, 2015

Time: 1:05 PM

Location: MRDC 4404

Committee:

Dr. Donggang Yao, MSE (Advisor)

Dr. Yulin Deng, ChBE

Dr. Anselm Griffin, MSE

Dr. Satish Kumar, MSE 

Dr. Youjiang Wang, MSE

Title:

Oligomer spin-solvent gel-fiber spinning

Abstract:

Successful processing of polymer molecules into well oriented fiber structures with minimal defects is difficult because the thermodynamically favorable state is a random coil, and molecular relaxation perpetually opposes efforts to extend and orient polymer molecules. This dissertation introduces the oligomer spin-solvent approach for gel-spinning high-strength fibers from many polymers with different chemistries. The theory is applied to two semi-crystalline, linear polymers without significant hydrogen bonding interactions: polyoxymethylene (POM) and polyethylene oxide (PEO). The resulting fibers are among the strongest POM and PEO fibers ever created. The efficiency of the gel-spinning process is increased through a mechanical solvent extraction method. By exploiting the unique solid-like behavior of the gel-fiber network, this work demonstrates that the spin-solvent can be separated from the gel-fiber by mechanically deforming the gel-network instead of chemically through an extraction solvent. A relatively safe and efficient gel-spinning process based on mechanical spin-solvent extraction is demonstrated using ultra-high molecular weight polyethylene.