Abstract:

The conventional thiol-ene photopolymerization formulation suffers from poor storage stability and bad odors due to the use of primary thiols, leading to their limited application range. In this paper, photopolymerization systems containing secondary thiol-acrylate are prepared and the effect of secondary thiol percentage on the stability of the formulation, thermal properties, mechanical properties and basic properties of the cured coatings is systematically investigated. The results show that the secondary thiol-acrylate systems exhibit better stability and still maintain flowable for 25 days at room temperature, while gelation is observed for the primary thiol-acrylate system within 24 hours. Compared to pure acrylate system, addition of 10% (thiol molar content) of secondary thiol can significantly inhibit oxygen inhibition on the surface and increase the double bond conversion from 47% to 78%. With the increase of secondary thiol content, the glass transition temperature, storage modulus and hardness of the coating decrease gradually while the flexibility, impact resistance and uniform of the polymeric films increase. Therefore, it is possible to tailor the properties of the cured film via altering the thiol content. The presented secondary thiol-acrylate photopolymerization formulation would expand the application range of UV curing technology.

Key words: thiol-acrylate, secondary thiol-acrylate, photopocuring, stability

摘要：

传统巯基-丙烯酸酯光固化配方由于使用一级硫醇,贮存稳定性差,气味大,应用范围受限。文章以气味较低的二级硫醇-丙烯酸酯体系为对象,系统研究了二级硫醇含量对配方的稳定性、涂层的热性能、机械性能和基本涂膜性能的影响。结果表明:二级硫醇-丙烯酸酯体系具有较高的稳定性,在室温下放置25 d仍保持良好的流动性,而一级硫醇-丙烯酸酯体系放置1 d即发生凝胶。相比于纯丙烯酸酯体系,加入10%(巯基摩尔含量)的二级硫醇即可显著抑制体系的表面氧阻聚,同时双键转化率由47%上升到78%;随着二级硫醇含量的继续增加,涂层的玻璃化转变温度、储能模量和硬度逐渐降低,固化膜的柔韧性、耐冲击性和聚合网络的均一性逐渐增加。因此,通过改变巯基含量可有效调控固化膜的性能,扩大光固化技术的应用领域。

关键词: 巯基-丙烯酸酯, 二级硫醇-丙烯酸酯, 光固化, 稳定性

CLC Number: 

• TQ630.4