【作者】 万婷；

【导师】 朱传方；

【作者基本信息】 华中师范大学 ， 有机化学， 2006， 硕士

【摘要】 水性聚氨酯由于其以水为分散介质,无毒、不易燃烧、不污染环境、安全可靠以及硬度高、附着力强等优点,符合发展涂料工业的要求,本论文研究了适合塑料印刷油墨及金属防腐的水性聚氨酯,并且用有机硅对水性聚氨酯进行改性。具体研究如下: 1.国内生产的油墨中,以丙烯酸树脂为基料的水性油墨与塑料的黏附力差,只适合于纸商标与纸箱包装方面,现对其工艺改进克服水性油墨弊端的研究很少,为适应塑料印刷的需要,以聚酯(PBA)、小分子醇、二羟甲基丙酸(DMPA)、异佛尔酮二异氰酸酯(IPDI)为原料,采用先乳化后扩链的合成方式制得阴离子型聚氨酯水乳液,研究了改变二异氰酸酯基与羟基的物质量比、DMPA质量百分含量等配比,对黏度、硬度、表观等综合性能产生的影响,结果表明:当异氰酸酯基(NCO)/羟基(OH)的物质量比为1.8,n(PBA)/n(小分子醇)为0.67—1,DMPA质量含量为4%,选择扩链剂为乙二胺(EDA),扩链剂质量百含量0.8%时,所合成的脂肪族水性聚氨酯附着性好、透明度高、黏度低等特点,符合塑料印刷油墨要求。 2.水性涂料也逐渐应用到金属防腐领域,为提高性能将高性能的水性聚氨酯也使用到水性防腐涂料中,其中防腐涂料配方中颜填料和基料的质量比(P/B)是影响涂料防腐性能的重要参数,直接影响涂层对腐蚀电解质的防渗透性,目前这方面的研究较少,为了合成防腐性能优良的防腐涂料,就需要确定涂料配方中P/B最佳的比例,以水性聚氨酯为基料,加入颜填料和助剂合成水性防腐涂料。改变涂料配方中颜填料和基料的质量比(P/B)制得样品,让样品在3%NaCl溶液中浸泡30天,通过防腐极化曲线测试和电化学交流阻抗测试,研究P/B对涂层的防腐性能影响,确定了涂料配方中P/B=0.8和1.5性能较好,P/B=0.8综合性能较好,但固化时间较长,而且树脂用量较大,增加了成本,P/B=1.5抗冲击能力较差,但其它性能良好,成本也比较低。 3.由于合成的水性聚氨酯是线性,其在耐水性、热稳定方面较差有待提高。为了克服这些缺点,需要对其进一步改性,有机硅突出的特点就是耐候性好和优良的疏水性,聚氨酯与有机硅共聚改性可以互相弥补缺点,发挥各自优点。通过两种方法将有机硅引入水性聚氨酯中,一种在合成预聚体的过程中将聚二甲基硅氧烷(PDMS)引入聚氨酯链段中,再分散于水中,得到交联水分散聚氨酯。另一种是在预聚体乳化的过程中用硅偶联剂扩链。改变PDMS的质量含量,研究对树脂性能更多还原

【Abstract】 Waterborne polyurethane is dispersed in water,its characteristics include innocuity, no flammability,no pollution,safety,high rigidity,better adhesion ect,which answer for need of coating development.In this paper, Waterborne polyurethane according with the require of printing ink and metal anticorrosive coating were researched,and organosiloxane modified polyurethane were studied.lt may be summarized as follows:1. In printing ink of our country, adhension of waterborne printing ink synthesized by using crylic acid in plastic is not good .The waterborne printing ink only adapt to paper brand and paper box packing.Studys on overcoming the defects of waterborne printing ink are a fat lot.To fitting the need of plastic print. The material of polyester,dimethylol propionic acid,isophorone diiocyanate were used to be synthesized anion acyclic waterborne polyurethane dispersion.Through changing the mole ratio of NCO to OH , mass content of DMPA, the effection of viscidity ,rigitidy, apparent etc were analysed to adjust the craftwork. Therefore,better property is the mole ratio of NCO to OH is 1.8 , mole ratio of PBA to glycerol is 0.67 to 1, DMPA mass content is 4% and chain extender was choosed EDA and chain extender mass content is 0.8% , the resin property of adhesion , transparence, viscidity etc were improved, the synthetical resin with accords with the require of printing ink basically.2. waterborne coating has been applied in metal anticorrosive field.To improve the property of waterborne anticorrosive coating, waterborne polyurethane has been used as anticorrosive coating. The pigment/binder ratio (P/B) of coating is the important parameter of effecting the coating performance, which impact the penetrability protection to the electrolyte. Now, the studys on P/B are less.In order to compose better property coating, a waterborne anticorrosive coating has been synthesized by using waterborne polyurethane, pigment and stuffing.The pigment/binder ratio of coating was changed. Samples were exposured to 3% NaCl solution for 30 days.The corrosion resistance properties of polyurethane paints was investigated by corrosion potential measurements and electrochemical impedance spectroscopy (EIS). Therefore, better anticorrosive protection is achieved by the coatings pigmented with P/B = 0.8 and 1.5. Although collectivity performance of P/B=0.8 are good, solidify time is long and resin is neededmore for increasing the cost.The impact resistance of P/B=1.5 is relative bad.but the other performances of it are well and cost is low.3. Due to the structure of synthetical waterbome polyurethane is linearity, the water resistance and heat resistance should be improved. Organosiloxane has better characteristic of weather resistance and water resistance. Organosiloxane modified polyurethane can make up the defects of each other and exert each virtues. The modified resins had been synthesized via inducting polydimethylsiloxane with IPDI and extending in emulsification using silane coupler.Change the mass content of PDMS, better property sample was choosed. Extending in emulsification using difference silane couplers, the best one was choosed. The two samples were compared with waterbrone polyurethane. The properties of the polyurethane were investigated using infrared spectroscopy (IR), DSC, TGA, tensile measurements, water contact angle and showed that thermal stability, the water resistance and solid content of the PU were improved. The aim was achieved.更多还原