玻璃化转变型温敏透湿织物涂层胶的制备

Preparation of Fabric Coatings with Thermal-sensitive Water Vapor Permeability Feature and Using T_g as Switch

制备了单组分水性形状记忆聚氨酯(1KWPU)和双组分水性聚氨酯(2KWPU)涂层胶。研究了交联剂和羟丙基-β-环糊精(H-CD)的用量对胶膜及织物涂层性能的影响。结果表明,1KWPU的玻璃化转变温度(Tg)约为25 ℃左右。可水分散多异氰酸酯作为1KWPU的交联剂能促进聚氨酯相分离。添加H-CD能明显降低2KWPU的Tg。制备的涂层织物在20~36 ℃的温度范围内具有温敏透湿性。随着交联剂用量的增加,涂层织物的耐静水压提高,而透湿性能下降。引入H-CD后,涂层织物的透湿性增加,但耐水压降低。当H-CD的质量分数为5%~7.5%时,涂层织物有较高的透湿性和耐静水压。

A one-component waterborne shape memory polyurethane (1KWPU) and several two-component waterborne polyurethanes (2KWPU) fabric coatings were prepared. The influences of the contents of cross-linkers and hydroxypropyl-β-cyclodextrin (H-CD) on the properties of fabric coatings were investigated. The results revealed that T g of the 1KWPU was about 25 ℃. The presence of water-dispersible polyisocyanates cross-linkers improved the phase separation of the polyurethanes. It was experimentally proved that water vapor permeability(WVP) of the coated fabrics exhibited apparent thermal-sensitive WVP feature in the temperature range 20~36 ℃. With the increase of the content of cross-linkers, resistance to hydrostatic pressure of the coated fabrics increased while WVP reduced. Incorporating H-CD into the polyurethanes resulted in the increse of WVP and the decrease of resis- tance to hydrostatic pressure of the coated fabrics. When the content of the H-CD was 5%~7.5%, the coated fabrics exhibited good thermal sensitive WVP characteristic and high resistance to hydrostatic pressure.