Accession Number : ADA337850

Title :   The Materials Science and Mathematics of Block Copolymers

Descriptive Note : Final rept. 15 Jun 94-14 Sep 97

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s) : Thomas, Edwin L.

PDF Url : ADA337850

Report Date : 15 FEB 1998

Pagination or Media Count : 7

Abstract : This project focused on the fundamentals of microstructural control of polymer materials for three-dimensional nano-composites. Our recent discovery of the double gyroid (DG) micro-domain structure in a poly styrene-poly isoprene di-block copolymer (Macromolecules 27, 4063 (1994)) opened the possibility for exploiting this new tri-continuous structure for physical properties. Two possible applications we envisioned were for tough thermoplastic elastomers and for nano-porous membranes. In the past three years, we demonstrated the attainment of this specific tri-continuous triply periodic micro-domain structure in two different tri-block copolymers for the first time, through targeted composition and chain architecture. Additionally we have collaborated with mathematicians to model the complex DG structure employing level set functions and to develop a software application program for producing 2D projections of the 3D micro-domain structure for comparison to TEM images. Two poly styrene-poly isoprene ABA tri-block samples which have the DG structure were synthesized and their large strain deformation behavior investigated using a combination of transmission electron microscopy (TEM) and in situ synchrotron small angle x-ray scattering (SAXS). Additionally, tri-block DG samples based on poly(pentamethyl disilylstyrene)-poly isoprene were synthesized and successfully converted into nano-porous materials via ozonolysis etching of the poly isoprene networks.

Descriptors :   *BLOCK COPOLYMERS, *NANOTECHNOLOGY, PLASTIC DEFORMATION, SOFTWARE ENGINEERING, MICROSTRUCTURE, POLYSTYRENE, ELASTOMERS, ELECTRON MICROSCOPY, THERMOPLASTIC RESINS, X RAY SCATTERING, ISOPRENE.

Subject Categories : Polymer Chemistry
      Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE