Abstract
The fracture resistance of epoxy resins was significantly improved through a new molecular toughening mechanism without sacrificing the desired thermal and mechanical properties. A liquid diglycidyl ether of bisphenol-A type epoxy resin (DGEBA) was modified with various methylphenyl siloxane (MPS) modifiers and then cured with two types of amine curing agents, meta-phenylenediamine (mPDA) and polyoxypropylene diamine (POPDA). The effects of such variables as the modifier type and concentration, and the curing agent type and curing cycle on the properties and the morphologies of the MPS-modified DGEBA systems were investigated. The glass transition temperatures (T g) of the siloxane-modified DGEBA/mPDA systems were well-maintained. Chemically modified DGEBA samples by various MPS modifiers demonstrate greater enhancements in both the fracture toughness (K Ic) and the fracture energy (G Ic) compared with the unmodified epoxy system. With an increasing siloxane content, both the values of K Ic and G Ic increase. The improvement of fracture toughness can be attributed to shear band formation, crack path deflection, trans-particle fracture, particle tearing and localized plastic deformation.
| Original language | English (US) |
|---|---|
| Pages | 2804-2810 |
| Number of pages | 7 |
| State | Published - 2006 |
| Event | Society of Plastics Engineers Annual Technical Conference 2006, ANTEC 2006 - Charlotte, NC, United States Duration: May 7 2006 → May 11 2006 |
Other
| Other | Society of Plastics Engineers Annual Technical Conference 2006, ANTEC 2006 |
|---|---|
| Country/Territory | United States |
| City | Charlotte, NC |
| Period | 5/7/06 → 5/11/06 |
ASJC Scopus subject areas
- General Chemical Engineering
- Polymers and Plastics