单组分湿固化聚氨酯密封胶储存稳定性的研究

单组分湿固化聚氨酯密封胶性能优良、使用方便，得到了广泛应用，但是储存时容易出现凝胶的问题。为了提高它的储存稳定性，可以在密封胶中添加脱水剂。实验结果表明添加脱水剂可以显著改善密封胶的储存性能，但是使密封胶的表干时间延长，流淌性增加。分析了添加脱水剂后密封胶储存稳定性提高以及表干时间延长的原因，研究了脱水剂的最优添加量。研究还表明了添加脱水剂后，密封胶的断裂伸长率、邵氏硬度、剪切强度等性能受到的影响很小。

The Study on Storage Stability of One - component Moisture - curing Polyurethane Sealant

One- cen-component, moisture- curing PU sealant was widely utilized for its convenience and excellent propertles,but it was easy to be gelation when storage. In order to improve its storage stability, adding dehydrating agent into the sealant was a possible way. The experiment results showed that adding dehydrating agent into the sealant obviously improved its storage stability but prolonged the tack free time of sealant and increased its flow property. The reasons of the improvement of stability and the prolongation of tack free time were analyzed and the optimal amount of dehydrating agent was studied in this article.The research also indicated that the performances of PU sealant such as ultimate elongation, Shore - A hardness and shear strength, ere were affected little afer adding dehydrating agent.