Waterborne polyurethane acrylic copolymer (WPUA) was synthesized from the poly(tetramethylene glycol) (PTMG), 4,4′-methylene bis(cyclohexyl isocyanate) (H₁₂MDI), 2,2-dimethylol propionic acid (DMPA), and caprolactone acrylate (CLA). The synthesis of WPUA was confirmed by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). Dynamic light scattering (DLS), universal testing machine (UTM) and water absorption tests were performed to confirm the change of the physical properties of WPUA according to the presence of CLA and the change of molecular weight of PU prepolymer. It was confirmed that the introduction of CLA improved the tensile strength and water resistance of WPU and decreased the elongation at break.

Poly(tetramethylene glycol)(PTMG), 4,4′-methylene bis(cyclohexyl isocyanate)(H₁₂MDI), 2,2-dimethylol propionic acid(DMPA)와 caprolactone acrylate(CLA)를 사용하여 수분산 폴리우레탄-아크릴 공중합체(waterborne polyurethane acrylic copolymer, WPUA)를 합성하였다. Fourier transform-infrared spectroscopy(FTIR)와 gelpermeation chromatography(GPC)를 통해 WPUA의 합성 여부를 확인하였으며, dynamic light scattering(DLS)과 universal testing machine(UTM) 측정 및 water absorption test를 통해 CLA의 유무와 폴리우레탄 prepolymer의 분자량 변화에 따른 WPUA의 물성 변화를 확인하였다. CLA의 도입으로 WPU의 인장강도와 내수성이 향상되었고 파단 신율은 감소하였다.

Keywords: waterborne polyurethane, waterborne polyurethane acrylic copolymer, anti-corrosion resin, mechanical strength, water absorption