Synthesis and characterization of hydroxyl functional acrylic copolymer for low VOC polyurethane coating

Purpose High solid acrylic (HSA) resins are not reported earlier with different initiators. Based on the experimentation, tertiary-butyl peroxy-benzoate (TBPB) is not suitable for HSA resin, as it produces resin with very high molecular weight distribution and simultaneously increases volatile organic compounds (VOCs) by taking more solvent for dilution. Thus, this study aims to extend the applicability of scrutinizing the initiator for HSA resin with low VOC. Design/methodology/approach HSA resin was synthesized using different initiators such as di-tertiary amyl peroxide (DTAP), tertiary butyl 2-ethylhexyl carbonate (TBEC) and TBPB. Experiments conducted with variation in initiator dosage and temperature; furthermore, its cross-linking with polyisocyanate is studied. Post-polymerization, viscosity, polydispersity index and free monomer content were characterized. Coating formulation was prepared, its physical properties and instrumental analyses such as molecular weight distribution, Fourier transform infrared, thermos-gravimetric analyzer and dynamic mechanical analyzer were studied. Findings An attempt has been made to select an effective initiator for the synthesis of HSA copolymer with reduced VOC in coating formulation. The effect of initiators and process parameters on physicochemical properties of HSA copolymer. Based on the observation of the 12 experiments using three initiators at two different dosage and temperature, their performance in coatings is summarized. Originality/value HSA resin synthesized using different initiators such as DTAP, TBEC and TBPB. Experiments conducted with variation in initiator dosage and temperature; furthermore, its cross-linking with polyisocyanate is studied.