封闭型水性聚氨酯合成及在纸张表面施胶中的应用

Synthesis of Closed Waterborne Polyurethane and Its Application in Paper Surface Sizing

关键词:  封闭型水性聚氨酯  R值  表面施胶  纸张性能

Key Words:closed waterborne polyurethane  R value  surface sizing  paper properties

摘要:采用一步聚合法，以聚乙二醇350单甲醚（mPEG350）、丁二醇（BDO）、二羟甲基丙酸（DMPA）、异佛尔酮二异氰酸酯（IPDI）为原料进行聚合，得到一种封闭型的水性聚氨酯（BWPU）。将质量分数1%的BWPU与质量分数4%的PVA复配成施胶液（SSA），用于纸张表面施胶。结果表明，当DMPA添加量为10%、n（mPEG350）∶n（BDO）=1∶0.2、n（—NCO）∶n（—OH）（R值）为1.8，甲乙酮肟（MEKO）添加量为21.3%时，制备得到的BWPU性能最佳，其粒径为291.0 nm，分散稳定性指数（TSI）为1.33。施胶后的纸张撕裂指数为11.9 mN·m²/g，挺度为95.8 mN，抗张指数为82.6 N·m/g，耐折度为3394次，接触角为79.69°，施胶度为28.14°；与原纸相比，各项指标分别提高了76.8%、43.4%、7.8%、71.2%、26.3%，1307.0%。与市售施胶剂施胶后纸张相比，各项指标分别提高了20.9%、8.1%、15.9%、15.2%、10.3%、24.0%。

Abstract:A one-step polymerization method was used to prepare a closed aqueous polyurethane （BWPU） polymerized with polyethylene glycol 350 monomethyl ether （mPEG350）， butanediol （BDO）， dimethylolpropionic acid （DMPA）， and isophorone diisocyanate （IPDI） as raw materials. The 1% BWPU and 4% PVA were compounded into a sizing solution （SSA） for paper surface sizing. The results showed that the optimized performance of BWPU could be obtained with the DMPA content of 10%， n（mPEG350）∶n（BDO）=1∶0.2， R value of 1.8， and ethyl methyl ketone oxime （MEKO） content of 21.3%， of which the particle size was 291.0 nm and the TSI was 1.33. After surface sizing， the paper had a better performance with the tear index of 11.9 mN·m²/g， the stiffness of 95.8 mN， the tensile index of 82.6 N·m/g， the folding endurance of 3394 times， the contact angle of 79.69°， and the sizing degree of 28.14°. Compared with the original paper， the indicators increased by 76.8%， 43.4%， 7.8%， 71.2%， 26.3%， 1307.0%， respectively. Compared with the paper sized with sizing agent on the market， the indicators increased by 20.9%， 8.1%， 15.9%， 15.2%， 10.3%， 24.0%， respectively.