Epoxy modification with poly(vinyl acetate) and poly(vinyl butyral). I. Structure, thermal, and mechanical characteristics

Abstract

Efficiency of the application of high strength heat resistant thermoplastics for improving fracture toughness and impact properties of epoxy resins motivated authors to try large-scale production thermoplastics for the same purpose. Epoxy/anhydride systems were modified by up to 8 wt % poly(vinyl acetate) (PVAc) and up to 6 wt % poly(vinyl butyral) (PVB). In epoxy-PVAc blends it was possible to obtain morphologies with continuous thermoplastic phase. However, only sea-island morphologies with a very small size of PVB-rich phase were observed in epoxy-PVB matrices. The former type of morphology allowed a notable 2.4-fold increase in the fracture toughness of epoxy resin and simultaneous up to 30% decrease in its' impact strength. The latter type of morphology caused a notably lower (45%) enhancement of the epoxy fracture toughness combined with a 50% increase in its' impact strength.

Epoxy nanocomposites as matrices for aramid fiber‐reinforced plastics

“…At the same time, epoxy oligomers are also known for their low impact and fracture toughness properties. Different modifiers are being used to solve this problem, such as rubbers [2,3], thermoplastics [4][5][6][7][8], or nanoparticles [9][10][11][12][13][14].…”

Rheology, morphological evolution, thermal, and mechanical properties of epoxy modified with polysulfone and cellulose nanofibers

“…However, epoxies with high crosslink densities are usually brittle, which limits their applications. Due to the high glass‐transition temperatures and good mechanical performance, the high‐performance thermoplastic polymers (TPs), such as polysulfone (PSF), polyethersulfone (PES), and polyetherimide (PEI) are usually incorporated to enhance or balance the mechanical and thermal properties of epoxies . In most cases, the epoxy/TP blends is homogeneous initially and phase separation takes place at a given reaction conversion.…”

“…The morphology formation greatly depends on such factors as TP concentration, component compatibility, and curing reaction. Because morphology can directly determine the final performance of materials, studies on phase separation evolution and morphology regulation have aroused much interest . The primary problem for the epoxy/TP blends is the significant increase in viscosity during the blending process that limits the TP contents.…”

Effect of modified phenolic resin on crosslinked network and performances of polyvinyl acetate blending emulsion

“…Moreover, the shear strength was improved greatly while at the sacrifice of loop tack and peel strength. Therefore, the emulsion adhesive is mainly modified by the additive modification, copolymerization and blending modification in recent years . In addition, many waterborne adhesives need to undergo heating curing at the final stage and PVAc emulsion adhesive is a very common thermosetting adhesive.…”