Influence of Crosslinking on the Mechanical Properties of High T(G) Polymers
Abstract
A study was conducted on the effects of crosslinking on the mechanical properties of high-T(g) polymers, with emphasis on the role of average crosslink density and on variations in the distribution of chain lengths between crosslinks. Two model systems were used: one based on the use of polystyrene/polystyrene interpenetrating polymer networks (Millar networks), and the other based on the use of bisphenol-A-type epoxy/methylene dianiline resins synthesized to provide controlled variations in network properties. With the Millar networks, which were prepared by polymerizing a crosslinking polystyrene network within a precrosslinked polystyrene matrix, measurements of creep, swelling, and rubbery modulus showed that the properties at equal average crosslink density were dominated by the crosslink density of the first-formed network. Thus, when networks formed at different times can interpenetrate, the continuity or coherence of each plays a major role in determining behavior. With the epoxy networks, viscoelastic and elastic response, stress-strain and impact behavior, fatigue crack propagation, and fracture toughness were determined primarily by the average crosslink density. A model was proposed to account for the morphologies and mechanical properties observed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1977
- Accession Number
- ADA054431
Entities
People
- John A. Manson
- Leslie H. Sperling
- Soojaa L. Kim
Organizations
- Lehigh University