Accession Number : ADA119969

Title :   Model Network Polymers.

Descriptive Note : Final rept,

Corporate Author : MINNESOTA UNIV MINNEAPOLIS DEPT OF CHEMICAL ENGINEERING AND MATERIALS SCIENCE

Personal Author(s) : Macosko,Christopher W

PDF Url : ADA119969

Report Date : Sep 1982

Pagination or Media Count : 10

Abstract : Under this grant we applied and extended a recursive theory which describes structural features of crosslinking polymers. We developed experimental techniques for synthesizing and characterizing model networks of polydimethylsiloxane. We successfully applied the recursive theory to predict basic structural parameters like: molecular weight, gel point and sol fraction at various stages during network formation. A recursive relation for the weight average molecular weight of the longest linear chain through the molecule was developed and found to correlate viscosity rise during network polymerization. Sol fraction results were used with the theory to predict crosslink density, junction functionality and trapped entanglement fraction. These parameters were used to test classical and more recent theories of rubber elasticity against stress strain response of the silicone networks. The contribution of chain-chain interactions, often called entanglements, was found to be significant. Twenty publications are listed in the report.

Descriptors :   *Polymers, *Molecular structure, *Networks, *Models, Stress strain relations, Methyl radicals, Parameters, Molecular weight, Polymerization, Silicones, Elastic properties, Crosslinking(Chemistry), Density, Chains, Siloxanes, Theory

Subject Categories : Plastics
      Nuclear Physics & Elementary Particle Physics
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE