Viscoelastic Properties of Alkoxy Silane-Epoxy Interpenetrating Networks

A model epoxy-silane interpenetrating network (IPN) was synthesized to simulate the molecular structure found at the fiber-matrix interphase. The Young's modulus (E) of the epoxy-silane IPN was determined% trough micromechanical analysis both quasi-statically and in the frequency domain. The ep...

Full description

Saved in:
Bibliographic Details
Main Authors: Jensen, Robert E, McKnight, Steven H, Palmese, Giuseppe R
Format: Report
Language:English
Subjects:
ADHESION
ALKOXY SILANE
AMINES
COMPOSITE STRUCTURES
CROSSLINKING(CHEMISTRY)
CURING AGENTS
DGEBA(DIGLYCIDYL ETHER OF BISPHENOL A)
DIFFERENTIAL SCANNING CALORIMETRY
EPOXY COMPOSITES
FREQUENCY DOMAIN
GLASS TRANSITION TEMPERATURE
GLYCIDYL ETHER
GPS(3-GLYCIDOCYPROPYLTRIMETHOXYSILANE)
HIGH FREQUENCY
IMPACT STRENGTH
IPN(INTERPENETRATING NETWORK)
Laminates and Composite Materials
MATRIX MATERIALS
METHANE
MODULUS OF ELASTICITY
MOLECULAR STRUCTURE
PACM(P-AMINOCYCLOHEXYL-METHANE)
PHASE STUDIES
REINFORCING MATERIALS
SILANES
SILOXANES
VISCOELASTICITY
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A model epoxy-silane interpenetrating network (IPN) was synthesized to simulate the molecular structure found at the fiber-matrix interphase. The Young's modulus (E) of the epoxy-silane IPN was determined% trough micromechanical analysis both quasi-statically and in the frequency domain. The epoxy-silane IPN was synthesized by diffusion of uncured diglycidyl ether of bisphenol A (DGEBA) epoxy resin and bis (p-aminocyclohexyl) methane (PACM) curing agent into spherical particles of condensed and crosslinked 3-glycidoxypropyltrimethoxysilane (GPS). This IPN composition was chosen to simulate the typical properties of a silane modified interphase found in glass reinforced composites. Differential scanning calorimetry showed that the glass transition temperature (Tg) of the initial crosslinked siloxane network increased upon cure of the DGEBA and PACM, but was still significantly lower than that of the neat epoxy matrix. Additionally, dynamic mechanical analysis was used in conjunction with the micromechanical C-Combining Rule to show that the Young's modulus of the epoxy-silane IPN spherical inclusions (E sub i) was decreased in comparison to the Young's modulus of the matrix epoxy (E sub m) at all temperatures. The time-temperature superposition (tTsp) principle was successfully applied to the epoxy-silane IPN to determine viscoelastic properties at high frequencies. The viscoelastic properties of the epoxy-silane IPN may have implications with respect to the ballistic impact resistance of composite structures used for U.S. Army applications. The original document contains color images. All DTIC reproductions will be in black and white.