Toughening of Epoxy Resins with Thermoplastics: 3. An Investigation into the Effects of Composition on the Properties of Epoxy Resin Blends

• Published in: Polymer international Vol. 42; no. 4; pp. 349 - 355
• Main Authors: Hourston, D. J., Lane, J. M., Zhang, H. X.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.04.1997; Wiley
• Subjects: Applied sciences; dynamic mechanical properties; epoxy resin; Exact sciences and technology; fracture toughness; Mechanical properties; Organic polymers; Physicochemistry of polymers; polyetherimide; polymer blends; Properties and characterization; Stress intensity factor; Polyfunctional compound; Property composition relationship; Concentration effect; Mechanical properties; Epoxy resin; Experimental study; Etherimide polymer; Glass transition temperature; Mixture; Modified material; Fracture toughness
• ISSN: 0959-8103; 1097-0126
• DOI: 10.1002/(SICI)1097-0126(199704)42:4<349::AID-PI710>3.0.CO;2-3

Three different epoxy resins, based on the diglycidylether of bisphenol A (DGEBA), triglycidyl‐p‐aminophenol (TGPAP) and tetra‐glycidyldiaminodiphenylmethane (TGDDM), which are di‐, tri‐ and tetrafunctional, respectively, were mixed in varying proportions and cured with both 3,3′‐diaminodiphenylsulphone and 4,4′‐[1,4‐phenylene(1‐methylethylidene)]bis(2,6‐dimethylbenzenamine) (EPON 1062‐M from Shell). All the blends could be satisfactorily cured and gave homogeneous materials. The dynamic mechanical and fracture properties of the cured materials were measured. It was found that the glass transition temperature varied with composition systematically, whereas values of the strain energy release rate (G1c) and the stress intensity factor (K1c) showed relatively small variations with the blend composition. Toughened epoxy resins were prepared by adding a polyetherimide (PEI), in varying proportions, to the resin mixture. The ‘toughenabilities’ of different resins, or resin mixtures, were compared. This showed that the 75/25 TGPAP/DGEBA resin mixture was the most toughenable. Adding 20% of PEI led to a more than three‐fold increase of the G1c value. © of SCI.