Acrylate Modified Waterborne Polyurethane

In this paper, isophorone diisocyanate(IPDI),dimethylol propionic(DMPA),polycarbonatediol (PC),hydroxypropyl methacrylate(HPMA) for the polyurethane raw material, butyl acrylate(BA), methyl methacrylate(MMA) as acid ester monomer, graft and crosslinking copolymerization of acrylic/poluurethane(PUA)hybrid emulsion.Fixed the amount of HPMA, emulsifier(SDS),initiator(APS), changing polyurethane to acrylic with the mass ratio, discussed the structure and properties of PUA hybrid emulsion. With the increase in acrylate content, the emulsion particle size increases, latex films heat resistance, water resistance, mechanical properties were improved significantly; Kinetics study shows that the-NCO in prepolymer and-OH in HPMA were the two order reaction, the reaction rate constant k=0.0021L-mol-1·S-1, PU molecular chain end double bond content with the increase of the amount of HPMA. PUA graft and crosslinking copolymers the existence of two molecular structure type; With the increase of emulsifier, the polymerization and conversion rate increased, improving the stability of emulsion, while the film of water absorption increased. PUA core-shell latex particles showed a clear structure, morphology and narrow particle size distribution between 60-120nm, the text showed a consistent size. FTIR showed that PU hard segment hydrogen bonding effect first increased and then decreased, the ordering of hard segment decreased. The compatibility between two components are better, there is only a glass transition temperature, with the increase of PA content gradually. The heat, water, mechanical properties are improved significantly. The heat resistance of PUA between two pure components, with the PA content in the copolymer increased, the water absorption of PUA film reduces, water resistance to increase, gradually increasing the elastic modulus, tensile strength, elongation at break of first increased, then decreased. The tensile strength and elongation at break of PUA-50 than two pure components of PU and PA. In the same reaction time, with the increase of the content HPMA, PU prepolymers of-NCO reaction more fully, after 3h, the system will not change-NCO content.BA,MMA by free radical solution polymerization, with mercaptoethanol(ME) as a chain transfer agent regulation of synthesis of different molecular weight hydroxyl-terminated polyacrylate(PA). Discussion of the chain transfer agent and initiator(AIBN) in the molar ratio of molecular weight. When the molar ratio more than 6/1, The ratio of terminal hydroxyl groups in PA reached 80%, meaning that 80%of the PA chains contained hydroxyl. By GPC,viscosity measured molecular weight and intrinsic viscosity, obtained PA copolymer at 25℃,acetone solvent characteristics of index K=2.76×10-4,α=0.72;-NCO in different molecular weight of hydroxyl-terminated with PU prepolymer reaction, dispersed in water by PA-PU-PA triblock copolymer emulsion. The copolymer structure was characterized by FTIR and1H-NMR, the results showed that with the mass ratio of PU and PA decrease, copolymer of acrylic ester content increase, The role of the hydrogen bonding between soft and hard segment of PU weakened. TEM showed uniform structured composite latex particle morphology and obvious core-shell structure. The modified latex membrane water,heat resistance with PU/PA ratio increased, the water absorption decreased from 25%to 5%, maximum weight loss temperature from 369℃to 432℃...