Preparation and Characterization of Polyaspartic and a High Solids Acrylic Copolymer Polyol Based Polyurethanes

Abstract

In this work, a high solids acrylic copolymer polyol (poly(MMA/BA/HEMA/AA)) was synthesized from the polymerization of methyl methacrylate (MMA), butyl acrylate (BA), hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) and was added to the polyaspartic resin. The polyaspartic-polyol mixtures reacted with polyisocyanates to create hybrid polyurethane-polyaspartic hybrid coatings. Different amounts of synthesized acrylic copolymer (5, 10, and 20% of total resin mixture) were mixed into polyaspartic resin and subsequently reacted with polyisocyanates in a 1:1 molar ratio. The characterization of the polymer was performed with Gel Permeation Chromatography (GPC), Fourier-Transform Infrared-Attenuated Total Reflection (FTIR-ATR) and Differential Scanning Calorimetry (DSC). The determination of physical and mechanical properties of the hybrid coatings was accomplished by hardness, glossiness, abrasion, stress-strain, corrosion, and impact tests. The results indicated that by adding high solids acrylic copolymer (HSAC), the drawbacks of polyaspartic resin (short pot life, hardness and brittleness, and poor adhesiveness) have been largely eliminated without reducing its intrinsic properties. The pot life increased from 16 minutes to 27 minutes and shore D hardness decreased from 60-65 to 52-55 as the polyol content increased in the mixtures. The acrylic polyols and aspartic mixtures may be used in the preparation of paints and varnishes applied on concrete, metal, and wood surfaces.