MECHANICAL MILLING AND ALLOYING OF HIGH PERFORMANCE POLYMERS
Katharine Nelson, Julie P. Martin, and Dr. Ron G. Kander
National Science Foundation Science and Technology Center:
High Performance Polymeric Adhesives and Composites,
and Department of Materials Science and Engineering
Virginia Polytechnic Institute and State University
Blacksburg, Virginia
Abstract
Mechanical milling (MM) (one component) and mechanical alloying (MA) (two components) were originally developed for processing metals. These new solid-state techniques are now used for processing and blending polymers. Two high performance polymers (PEEK and LaRC-TPI) were selected for a study of their morphology after this processing. The samples were milled at both cryogenic and ambient temperatures. A decrease in the crystallinity of the LaRC powders was found. However, strain induced crystallization was found in the PEEK powders upon milling. Milling and alloying produced a refined size and a more flake like texture of the powder particles. Cryogenic alloying produced a high level of mixing at the sub-micron scale in a plate-like lamellar structure. Processing produced some lowering of the degradation temperature. Based upon these experiments, MM and MA are viable processes for the processing and blending of polymers to achieve new and useful properties.