基于醛酮树脂的聚氨酯分散体的涂膜性能研究

摘要

以二羟甲基丁酸(DMBA)和新型聚氧乙烯醚作为亲水单体,以聚己二酸新戊二醇酯(PNA)、醛酮树脂、异佛尔酮二异氰酸酯(IPDI)为主要原料,采用预聚体法合成了阴/非离子型聚氨酯分散体(PUD),并以此为主要组分制备了水性涂料.研究表明,醛酮改性的聚氨酯分散体具有较小的粒径和较低的黏度,耐热性良好,适用于涂料产品；当亲水基团含量为25 mmol/100 g,醛酮树脂含量为40％,n(-NCO)∶n(-OH)=1.3时涂膜的综合性能最好,涂膜硬度可达4H,且涂膜附着力、柔韧性、耐冲击性和耐水性优异.%An anionicon - ionic type polyurethane dispersion(PUD) was synthesized by using 2,2 -dimethylolbutyric acid(DMBA) and a new polyoxyethylene ether as hydrophilic monomer, polyneopentane-diol adipate( PNA) , keto - aldehyde resin and isophorone diisocyanate (IPDI) as raw materials by a prepoly-merization process. Which was then used as a main material to prepare the waterborne coatings. Results showed that keto - aldehyde resin modified polyurethane dispersions had advantages of small particle size, low viscosity and good heat resistance, so it were suitable for use in coating products. When the hydrophilic group content was 25 mmol/100 g, keto - aldehyde resin content 40% , and -NCO/-OH molar ratio 1. 3 , the film showed the best comprehensive performance, such as pencil hardness(4H) , adhesion, flexibility, impact resistance and water resistance.