Study On The Preparation And Properties Of High Solid Content Of Hydroxyl Acrylic Coating Resins

Haze has been raging in recent years.In order to reduce the emission of organic solvent and protect our environment,the high solid content hydroxyl acrylic resins were synthesized by solution polymerization in this thesis.The high solid content of hydroxyl acrylic resins can greatly reduce environmental pollution because of the less content of organic solvent.Meanwhile,the n-butanol was used as the second solvent instead of partial xylene based on the idea of using low-toxic or non-toxic solvent,so the toxicity of resins solution was further reduced.In this thesis,the high solid content hydroxyl acrylic resins were synthesized by continuous dropping of initiator and monomers.The effects of the mixed solvents,the ratios of soft and hard monomers,the amount of initiators,etc,on the resins properties were studied.The resins were mixed with isophorone diisocyanate(IPDI)in a certain proportion and obtained a two-component coating.The structure of the cross-link cured coating films was characterized by FTIR spectrometer.The drying time,hardness,adhesion,impact strength,flexibility,and the resistance of water,solvent,acid and alkali of the coating films were all studied.The optimal experimental conditions were determined as followed: polymerization temperature 80°C,initiator content 2.5%,butyl acrylate content 24.5%,styrene content 19%,methyl methacrylate content 10% and hydroxyl ethyl acrylate content 10%.Finally,the hydroxyl acrylic resins with solid content about 65% and excellent properties were successfully prepared.The experimental results showed that the resins viscosity decreased with increasing of the content of styrene and butyl acrylate,which improved the performance of the coating films.In addition,a series of hydroxyl acrylic resins with different mass ratios of solvent(n-butanol/xylene)were prepared.The effects of the mass ratios of mixed solvent on the viscosity,the hardness,the adhesion and other properties were also studied.These experimental results showed that the use of mixed solvent,especially the addition of the second solvent n-butanol obviously decreased the viscosity of the resins,and shorten the drying time.Meanwhile,the other properties of the coating films were nearly same as the properties of the xylene single solvent system.