【作者】 刘身凯；

【导师】 涂伟萍；

【作者基本信息】 华南理工大学 ， 化学工程， 2010， 硕士

【摘要】 双组分水性聚氨酯具有溶剂型双组分聚氨酯的高性能和水性体系低VOC值的双重优点,其中双组分水性聚氨酯用水性聚酯的研究与开发日益成为热点。由于传统水性聚酯易水解,其应用受到一定限制。本文旨在开发一种高稳定的水性聚酯分散体,探讨各因素对合成过程的影响;将其与多异氰酸酯固化剂复配成膜,研究各种因素对其性能的影响,寻找适宜的固化工艺条件。本文用乙二醇(EG)、新戊二醇(NPG)、三羟甲基丙烷(TMP)作为醇组分,四氢苯酐(THPA)和1,4-环己烷二甲酸(CHDA)作为酸组分,同时通过向聚酯分子中引入含磺酸盐亲水单体,采用直接酯化的方法制备了高稳定的水性聚酯分散体,发现合成工艺、原料的配比、亲水单体的用量、催化剂等因素对其性能均有不同程度的影响。实验研究发现:采用先熔融反应后回流反应的合成工艺避免了醇组分的较大挥发,同时得到了酸值较低的树脂;用三羟甲基丙烷的加入量来调节聚酯树脂的羟值,当三羟甲基丙烷的用量占原料总摩尔量的8%~10%,所得树脂羟值为120~140 mgKOH/g;酸组分中四氢苯酐和1,4-环己烷二甲酸按摩尔比为3:1加入时所得水性聚酯综合性能最好;亲水单体用量对水性聚酯分散体的水分散性、粘度、稳定性以及涂膜后的耐水性均有不同程度的影响,控制其占树脂总量的5.3%时,涂膜综合性能较好;选用有机锡化合物为催化剂,用量为0.1%催化效果最明显;使用质量比为7:3的二乙二醇乙醚醋酸酯(DGME)和120#溶剂油复合助溶剂体系,加入量为10%时助溶效果显著,能形成稳定乳液,且涂膜外观平整,流平性好,无气泡;以二甲基乙醇胺(DMEA)作为中和剂,能提高中和树脂的溶解参数,减少亲水单体的用量,降低涂料的色度,提高涂膜的光泽和耐水性;中和度为90%时,水性聚酯的粘度适宜,且涂膜的丰满度较好。以上述自制的水性聚酯、拜耳的水性丙烯酸(BayhydrolA145)和拜耳的水性聚酯(Bayhydrol D270)为羟基组份,分别与拜耳的固化剂(Bayhydur? XP2487/1)进行复配,其中-NCO/-OH摩尔比值为1.5,固化温度为25~80℃,固化时间为7天,结果表明,以自制的水性聚酯分散体复配所得双组分水性聚氨酯清漆涂膜具有硬度高、光泽度好、附着力强、耐水性好等特点,其综合性能优于以拜耳的水性丙烯酸和水性聚酯配置的双组分水性聚氨酯清漆涂膜的性能。更多还原

【Abstract】 Two-component waterborne polyurethane systems combine the good film properties ofsolvent-borne polyurethane with low VOC values of waterborne system. At present, researchand development on waterborne polyester which will be used on two-component waterbornepolyurethane have attracted more and more interest. However, applications are limitedbecause it is easilyhydrolyzable. Thus, in this paper a kind of waterborne polyester dispersionwith high stability was prepared, and the influence of various factors on its synthesis processwas discussed, and then prepares film with mixed hydroxyl component isocyanate, lookingfor appropriate curing conditions.In this paper, EG, NPG and TMPwere chose as alcohol component, THPAand CHDAasacid component, at the same time high stability waterborne polyester dispersoid wassynthesized through esterification process with the sulfonic hydrophilic monomer. It is foundthat the performance of waterborne polyurethane was influenced by varying degree ofpreparation process, materials, content of hydrophilic monomer, catalyst and so on. Whencombination of melting reaction and reflux process was adopted, great loss of material wasavoided and resin of low acid value was obtained; with the addition of TMP to regulate theamount of hydroxyl value of polyester resin, when the dosage of TMP was 8%~10%,hydroxyl value of the resin was 120~140 mgKOH/g; when the molar ratio of THPA and 1,4-CHDA was 3:1, overall performance of the waterborne polyester resin was the best;hydrophilic monomer has different level impact on the water dispersion, viscosity, stabilityand water resistance of aqueous polyester dispersion, and the proper hydrophilic monomercontent was 5.3%(w/w); chose organic tin compounds as catalyst and the dosage of catalystwas 0.1%; when the dosage of mixed cosolvents(DGME:solvent oil=7:3) was 10%, it couldform a stable emulsion, and the film looked flat, good leveling and had no bubbles; chosingDMEA as a neutralizer it could increase the dissolution parameters, reducing the amount ofhydrophilic monomer, the color of paint, improving the gloss and water resistance of thecoating; when neutralization degree was about 90%, the water-based polyester had suitableviscosityand the coating film had good fullness degree.The self-made water-based polyester, Bayer waterborne acrylic (Bayhydrol A 145) and Bayer waterborne polyester (Bayhydrol D270) were used as the hydroxyl group torespectively compound with Bayer solidifying agent (Bayhydur ? XP 2487/1) at thecondition of -NCO/-OH molar ratio 1.5, curing temperature 25~80℃, curing time 7 days.Results showed that two-component waterborne polyurethane coating varnish mixed fromself-made polyester resin dispersion has high hardness, good gloss, strong adhesion, excellentwater resistance and so on. Its overall performance of coating varnish is better than that mixedfrom the Bayer water-based acrylic and polyester resin.更多还原