Core‐shell and interpenetrating‐network PU/AC hybrids: synthesis and comparison – waterborne polyurethane/polyacrylate hybrid dispersions

Abstract

Purpose -The purpose of this paper is to synthesise polyurethane/polyacrylate (PU/AC) core-shell hybrid latex by emulsion polymerisation (PUA) and interpenetrating hybrid latex by soap-free emulsion polymerisation techniques latex interpenetrating polymer networks (LIPN) and to compare their physico-chemical and thermo-mechanical properties. Design/methodology/approach -The interactions between the PU and AC components in hybrid coatings were studied with infrared spectroscopy. Mechanical properties were determined by measuring Shore A hardness, pencil hardness and flexibility of dried films. A particle size analyser and scanning electron microscopy were used to investigate the morphology of hybrid resins. Differential scanning calorimetry and thermogravimetric analysis were performed to investigate the thermal stability of polymeric films. Findings -The core-shell hybrids had better physico-chemical and thermo-mechanical properties than LIPN hybrids, attributing better interpenetration and entanglement between PU/AC in emulsion polymerisation.Research limitations/implications -The syntheses of hybrid polymers can be extended for various combinations of acrylate monomers with crosslinkers, as well as for different types of PU ionomers. Practical implications -The comparative study provides a simple and practical solution to improve performance characteristics of PU/AC hybrid coatings, which also proves to be cost effective. Originality/value -The findings are of interest to those in surface coatings and adhesive applications.

Synthesis of Waterborne Polyurethane by the Telechelic α,ω-Di(hydroxy)poly(n-butyl acrylate)

“…As we mentioned in the Introduction, low compatibility between the polyurethane and the polyacrylate has limited the applications of waterborne polyurethane–polyacrylate hybrid emulsions [ 13 , 14 , 15 ]. Therefore, a DSC thermogram of the PBA-based PUD film was measured, and the result is shown in Figure 8 .…”

“…Because the structure and functionality of the polyacrylate polyol chains are inhomogeneous, and cross-linking reaction may occur when this kind of polyol reacts with isocyanate, polyacrylate polyols are seldom used to prepare aqueous PUDs. Although preparation of the waterborne polyurethane–polyacrylate hybrid emulsions has been reported, low compatibility between the polyurethane and the polyacrylate has limited its applications [ 12 , 13 , 14 , 15 , 16 ]. This problem can be solved by using the polyacrylate as soft segments of aqueous PUDs.…”

Polyurethane/poly(ethylene‐co‐ethyl acrylate) and functional carbon black‐based hybrids: Physical properties and shape memory behavior

“…The improved properties of physical blends were attributed to increase in inter-phase compatibility and improved phase dispersion. 24,25 In this study, PU/PEEA blend was reinforced with functional CB (0.1-1 wt %). Functionalization of CB was employed to induce better interaction and compatibility between the blend components and nanofiller.…”

Effect of Incorporating a Diurethane Monomethacrylate Monomer into Acrylic Latexes

“…The addition of urethanes to acrylics has shown to enhance the overall properties of the coatings such as excellent toughness, improved chemical resistance, and abrasion resistance. − Waterborne polyurethanes (PUD)­s are dispersions with a relative high molecular weight that do not usually mix well with acrylics. − There is an increasing interest to blend PUDs and acrylic latexes, combining the superior properties of polyurethanes with polyacrylates, thus lowering cost . Consequently, different approaches have been developed to eliminate this issue, including grafting, − interpenetrating polymer networks (IPNs), − PUD seed − and acrylic carbamate monomers. − …”

“…Another approach is building a PUA IPN structure. − Chai and Zhang compared the performance properties of PUD, core–shell PUA latex, and PUA IPN latex. Although PUA IPN latex film was less flexible, it showed better wet rub fastness, solvent resistance, and adhesive resistance.…”