无有机溶剂法合成水性聚氨酯-聚丙烯酸酯胶粘剂

Systhesis and property of acrylate modified waterborne polyurethane adhesive by solvent-free method

采用羧酸型亲水扩链剂二羟甲基丁酸(DMBA)以及磺酸型亲水扩链剂2,4-二氨基苯磺酸钠(SDBS),选用乙烯基单体作为聚氨酯(PU)预聚合的连续相,制备了稳定的无挥发性有机溶剂(VOC)水性聚氨酯-聚丙烯酸酯(SPUA)胶粘剂。利用傅里叶变换红外光谱(FT-IR)对改性前后PU的分子结构进行分析对比,并考察了亲水扩链剂用量、聚丙烯酸酯(PA)含量对胶粘剂的耐水性、稳定性和力学性能的影响。结果表明。当SDBS含量为2%(wt,质量含量,下同),DMBA为4.5%,PA为25%时,SPUA胶粘剂的耐水性、稳定性和力学性能最佳,固含量可达43%。透射电镜(TEM)照片表明,SPUA乳胶粒呈圆球状,乳液平均粒径分布均匀。

Waterborne polyurethane prepolymer was synthesized by using 2,2-dimethylol butyric acid（DMBA）and2,4-diaminobenzenes sulfonic acid sodium salt（SDBS）as hydrophilic chain extender agent.Vinyl monomer used as the continuous phase of polyurethane in pre-polymer preparation.And the solventless and stable polyurethane-polyacrylate（SPUA）adhesive emulsion with high solid content was obtained.The structure of film before and after modification were confirmed by fourier transform infrared spectroscopy（FT-IR）.The influences of SDBS,DMBA contents and PA content on the water resistance,stability and mechanical properties of adhesive emulsion and film were studied.When w（SDBS）=2%,w（DMBA）=4.5%,w（PA）=25%,the water resistance,stability,mechanical properties and stability of adhesive were the best,its solid content reached 43%.Transmission electron microscope（TEM）photos showed that SPUA emulsions dispersed well with neat appearance.