Reactive blending of functionalized acrylic rubbers and epoxy resins

• Published in: Polymer engineering and science Vol. 41; no. 9; pp. 1486 - 1496
• Main Authors: Dispenza, C., Spadaro, G., Carter, J. T., McGrail, P. T.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.09.2001; Wiley Subscription Services; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd
• Subjects: Applied sciences; Electric properties; Epoxy resins; Exact sciences and technology; Mechanical properties; Organic polymers; Physicochemistry of polymers; Polymers; Properties and characterization; Rubber; United States; Curing(plastics); Acrylic elastomer; Morphology; Epoxy resin; Mechanical properties; Experimental study; Chemical reactivity; Modified material
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.10847

A high molecular weight acrylonitrile/butadiene/methacrylic acid (Nipol 1472) rubber is chosen to control processability and mechanical properties of a TGDDM (tetra glycidyl diphenyl methane) based epoxy resin formulation for aerospace composite applications. The physical blend of rubber and epoxy resin, achieved by dissolution of all the components in a common solvent, forms a heterogeneous system after solvent removal and presents coarse phase separation during cure that impairs any practical relevance of this material. A marked improvement of rubberepoxy miscibility is achieved by reactive blending (‘pre‐reaction’) the epoxy oligomer with the functional groups present in the rubber. The epoxy‐rubber ‘adduct’ so obtained appears as a homogeneous system at room temperature and also after compounding with the curing agent. Depending on the nature and extent of interactions developed between the rubber and the epoxy resin during ‘pre‐reaction,’ materials with different resin flow characteristics, distinctive morphologies and mechanical properties after curing were obtained. The effect of ‘pre‐reaction’ on the resin cure reaction kinetics has been also investigated.