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Polyurethane polyurethane, it is widely used in the paint industry. Solvent-based polyurethane coatings currently used, which cause harm to the environment. Water-based paint has a convenient source of easy purification, the characteristics of low-cost, good adaptability of the coating, non-toxic and non-irritating, become a direction of development of the coatings industry. Rosin is of a very rich forest resources, rosin-based chemicals with biodegradable, pollution-free green method developed to meet the market demand in China and the superior overall performance of the rosin-based polymers, both to take full advantage of our country advantage of resources, the development of the national economy while protecting the environment, is an important topic of rosin modified in a wide range of applications such as coatings and adhesives industry. Firstly, Maleic Rosin Cordier Addis verde synthesis of maleic rosin, synthetic product yield of 86% rosin and maleic acid, maleic the rosin acid value 390mgKOH / g (the theoretical acid 402mgKOH / g), and use Infrared Characterization of the structure, followed by the esterification reaction is the synthesis of maleic rosin glycol esters, esterified product of maleic rosin ester product of ethylene glycol was 88% of maleic rosin and the ethylene glycol. Maleic rosin glycol ester acid value for 105mgKOH / g (theoretical acid 110mgKOH / g), infrared spectroscopy, nuclear magnetic characterization of its correct structure. The glycol ester of maleic rosin is a hydrophilic chain extender instead of the usual dimethylol propionic acid and an isocyanate monomer, polyethylene glycol and ethylene glycol, etc. to prepare the aqueous polyurethane. Synthesis NCO-terminated prepolymer process, investigated the influence of the reaction time, the reaction temperature and the raw material formulation of the final product properties. The cured polymer were characterized by FT-IR and 1H-NMR results proved to be consistent with the molecular structure of the design. Using TGA its thermal stability, and tested the dispersion of the particle size and molecular weight. The systematic study of the physical properties of the paint film, such as the mechanical properties of the film such as hardness, impact strength, flexibility, gloss, and adhesion, focused on the water resistance of the paint film, and its improve the film water resistance process. In order to further improve the film performance such as water resistance and hardness, the paper used to join the aziridine cross-linking agent with the aqueous polyurethane structure in the side chain carboxyl group of the hydrophilic group-reactive with the epoxy, acrylic, and organosiloxane ADD to the above polyurethane dispersions to be modified, in order to form a crosslinked network structure to improve the performance of aqueous polyurethane film. Experimental results show that the the above film hardness of 6H, the contact angle of 90 ° or more, the flexibility of the paint film is 0.5 mm, the adhesion of two, the impact strength and gloss are very good, suggesting that the synthesized rosin-based aqueous polyurethane, the better the performance, comply with the green environmental protection requirements, and has broad application prospects in the coatings and adhesives industry.
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