Epoxy formulation including an acrylic triblock copolymer adapted for use in filament winding

• Published in: Polymer engineering and science 2016-10, Vol.56 (10), p.1153-1159
• Main Authors: Sáiz, Luciana M., Orofino, Antonela B., Rodríguez, Exequiel S., Zucchi, Ileana A., Williams, Roberto J. J.
• Format: Article
• Language: English
• Subjects: Bisphenol A; Block copolymers; Chemical properties; Chemical synthesis; Filament winding; Filament wound construction; Formulations; Glass transition temperature; Methods; Polymethyl methacrylates; Polymethylmethacrylate; Production processes; Viscosity
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.24348

Commercial triblock copolymers with a poly(butyl acrylate) (PBuA) central block joined to two poly(methyl methacrylate) (PMMA) end blocks (denoted as MAM) or to two random copolymers end blocks based on MMA and N,N′‐dimethylacrylamide (DMA) (denoted as MAM‐N), can be employed as toughening agents for thermoset composites. However, their use in epoxy formulations for filament winding, requiring low viscosities during the fiber‐impregnation step associated with an adequate glass transition temperature of the cured product is not trivial. In this study, we show that a blend of diglycidylether of bisphenol A (DGEBA), 4,4′‐diamino‐3,3′‐dimethyldicyclohexylmethane (3DCM) and benzylamine (BA), with 20% of amine hydrogens provided by BA, and containing 5 wt% MAM, can be used for these purposes. The addition of MAM increased the critical stress intensity factor from 0.63 MPa.m1/2 to 1.0 MPa.m1/2, the glass transition temperature from 138°C to 145°C, and the glassy modulus at 25°C from 2.95 GPa to 3.15 GPa. MAM was a better choice for the envisaged applications than MAM‐N because it led to solutions of lower viscosity. The higher viscosity produced by MAM‐N was explained by specific interactions between the epoxy‐amine solvent and DMA units present in its terminal blocks. POLYM. ENG. SCI., 56:1153–1159, 2016. © 2016 Society of Plastics Engineers