Preparation and Properties of Blocked Solvent-free Polyurethanes

被引：0

作者：

Liu, Shuai ^{[1
]}

Ma, Xing-Yuan ^{[1
]}

Ding, Bo ^{[1
]}

Zhang, Ming-Rui ^{[1
]}

He, Yuan-Xin ^{[1
]}

He, Ying-Hua ^{[1
]}

Wu, Xiao-Zhen ^{[1
]}

机构：

[1] College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an,Shaanxi,710021, China

来源：

Jingxi Huagong/Fine Chemicals | 2019年 / 36卷 / 06期

关键词：

Blocked SFPU - Blocking ratio - Curing condition - Deblocking - Film-forming properties - Sealer;

D O I：

10.13550/j.jxhg.20180842

中图分类号：

学科分类号：

摘要：

Blocked solvent-free polyurethanes were composed of hydrogenated phenylmethane diisocyanate (H12MDI) and polyester diol 2000 using dibutyltin dilaurate (DBTD) as catalyst, methyl ethyl ketone oxime (MEKO) and caprolactam as blocking agents, respectively. The blocked solvent-free polyurethane (SFPU) film was prepared by a prepolymer blocking method. The deblocking temperature and thermal properties of the blocked SFPU films were investigated by TGA and DSC. The effects of different sealers, leveling agents, catalyst dosage, oven temperature and blocking ratio on the deblocking temperature of the blocked SFPU, the curing conditions of the blocked SFPU and the film forming properties were investigated. The results showed that the deblocking temperature of the blocked SFPU with MEKO as blocking agent was 143.3℃ and that of the blocked SFPU with caprolactam asblocking agent was 163.7℃ by differential scanning calorimetry (DSC). TGA analysis showed that at the same deblocking temperature, the blocking speed of the blocked SFPU with MEKO as blocking agent was significantly higher than that of the blocked SFPU with caprolactam as blocking agent. Under suitable curing conditions of oven temperature of 143℃, leveling agent mass fraction of 5%, and catalyst mass fraction of 5‰, the blocked SFPU can be cured into a film. And the lower the blocking ratio of the blocked SFPU, the higher the curing temperature, the shorter the initial film forming time and the complete curing time of the blocked SFPU. From the six percentage closure gradients of 75%, 80%, 85%, 90%, 95% and 100%, the mechanical properties of the film increased with the increase of the blocking ratio. © 2019, Editorial Office of FINE CHEMICALS. All right reserved.

引用

页码：1191 / 1197