Preparation of nanosilica reinforced waterborne silylated polyether adhesive with high shear strength

Abstract

Waterborne adhesives are extremely environment-friendly but unfortunately deficient in mechanical properties. In this article, nanosilica, stemming from tetraethyl orthosilicate (TEOS), silica sol, and/or fumed silica powder, was employed to reinforce the waterborne silylated polyether adhesives. Effects of TEOS content, silica sol content, and the type and content of fumed silica on the shear strength of the adhesive were investigated using a scanning electronic microscope and an electronic instron tester and the strengthening mechanisms of different silica source were discussed. All the shear strengths of silylated polyether adhesives first increased and then decreased as TEOS content, silica sol content or fumed silica content increased. Colloidal silica particles was less efficient than fumed silica particles for reinforcing the polyether adhesive but can increase the shear strength of hydrophobic fumed silica embedded adhesive. Comparing the adhesives with the hydrophilic fumed silica (HS-5) or the extremely hydrophobic fumed silica (TS-720), the adhesive with moderate hydrophobic fumed silica (TS-610) had the highest shear strength. The maximal shear strength of 2.5 MPa was achieved when TEOS, silica sol, and fumed silica were combined. It seemed that TEOS, silica sol, and fumed silica played crosslinking (with polyether chain), dispersing (for fumed silica), and reinforcing roles on waterborne adhesive, respectively. This reinforcing mechanism opened a new way to fabricate waterborne adhesives (or coatings) with high performances.

Modified Nanocrystalline Cellulose Used for Improving Formaldehyde Emission and Bonding Strength of Urea Formaldehyde Resin Adhesive

“…Nanofillers are efficient to improve the properties of UF resin adhesive, such as nano-elastomeric copolymer and nano-silica [6]. Recently, cellulose-based nanocomposites have been receiving considerable attention owing to its optical, biocompatibility, low toxicity, and mechanical properties and its many promising potential applications in biomedical fields and targeted drug delivery [7].…”

Cellulose nanofibrils as filler for adhesives: effect on specific fracture energy of solid wood-adhesive bonds

“…From composite science it is known, that the smaller the fiber diameter, the higher the attainable strength will be (Griffith 1920 ). Consequently, there were several attempts in the past to improve the mechanical performance of adhesive joints by reinforcing the adhesive with nanoparticles (Zhang et al 2008 ; Ahmad et al 2010 ; May et al 2010 ; Khoee and Hassani 2010 ) or nanofibers (Hsiao et al 2003 ; Ureña et al 2008 ; Khalili et al 2008 , 2009 ; Prolongo et al 2009 , 2010 ; Yoon et al 2010 ) from high-strength materials.…”

Rheological and Thermomechanical Characterizations of Fumed Silica-Filled Polybenzoxazine Nanocomposites

“…The addition of this kind of nanofiller has a potential to improve heat distortion temperature, decrease moisture uptake, increase stiffness and strength, and increase flame resistance due to the size in nano scale and outstandingly high aspect ratio. Because of many beneficial points, the nanocomposites between the nanofiller and various polymers, such as epoxy [8]- [9], polypropylene [10] , polyethylene [20], polyethylene terephthalate [21], cyanate ester [22]- [23] and silylated polyester [24], are the point of interest at present. However, there has been no investigation about fumed silica filled polybenzoxazine.…”