含氟聚硅氧烷改性水性聚氨酯的制备及其性能

Preparation of waterborne polyurethane modified with fluorinated polysiloxane and its properties

为提高水性聚氨酯涂层剂的拒水性能,以异佛尔酮二异氰酸酯(IPDI)和聚醚N210为原料,羟丙基封端含氟聚硅氧烷为改性剂,二羟甲基丙酸(DMPA)为亲水单体,三羟甲基丙烷(TMP)为扩链单体,合成含氟聚硅氧烷改性水性聚氨酯。探讨了DMPA用量、改性剂分子质量及用量对其乳液及胶膜性能的影响,并将乳液用于织物涂层整理。结果表明:随着DMPA用量增加,乳液稳定性变好,粒径变小,胶膜疏水性变差;随着改性剂分子质量的增大和用量增加,乳液稳定性变差,粒径变大,胶膜疏水性变好;当DMPA用量为5%、改性剂分子质量为1 694、用量为6%时,水性聚氨酯综合性能达到最佳,涂层织物接触角为138.2°,静水压为6.32 kPa。相对未改性水性聚氨酯,改性水性聚氨酯涂层织物的拒水性得到明显改善。

In order to enhance the water resistance of polyurethane coating agent,waterborne polyurethane modified by fluorinated polysiloxane was synthesized with isophorone diisocyanate（IPDI）and polyether（N210） as raw materials,hydroxyl terminated fluorinated polysiloxane as modifying agent,dimethylol propionic acid（DMPA） as hydrophilic monomer,and trimethylolpropane（TMP） as chain extender.The effect of the dosage of DMPA,the molecular weight and dosage of modifying agent on the properties of emulsion and its film were discussed,and the modified polyurethane was applied to coat the polyester fabric.The results showed that the stability of the emulsion increased,the particle size of the emulsion decreased,and the hydrophobicity of the film decreased as the dosage of DMPA increased.The stability of the emulsion decreased,the particle size of the emulsion increased,and the hydrophobicity of the film increased as the molecular weight and dosage of modifying agent increased.The performance of waterborne polyurethane achieved the optimum value when the dosage of DMPA was 5%,the molecular weight of modifying agent was 1 694 and its dosage was 6%,the water contact angle of the coated fabric with modified waterborne polyurethane was 138.2°,the hydrostatic pressure of the coated fabric was6.32 kPa.Compared with the unmodified polyurethane,the water resistance of the fabric coated with modified waterborne polyurethane was improved significantly.