硬脂酸改性超支化聚酯无氟水性聚氨酯拒水剂的制备及性能

Preparation and properties of fluoride-free water repellents of waterborne polyurethane stearic acid modified hyperbranched polyester

以端羟丙基硅油(数均分子量2 000)、三羟甲基丙烷(TMP)、N-甲基二乙醇胺(N-MDEA)和甲苯二异氰酸酯(TDI)等为原料合成水性聚氨酯(WPU)。为了引入疏水支链结构,采用硬脂酸对端羟基超支化聚酯进行端基改性,得到硬脂酸封端的超支化聚酯。将WPU与硬脂酸改性超支化聚酯(SA-HBPE-3)进行复配,并应用于织物。采用红外光谱对改性前后的WPU及SA-HBPE-3的结构进行表征。通过静态水接触角、吸水率及应用测试,研究了SA-HBPE-3含量对SA-HBPE-3/WPU胶膜耐水性、表面能及拒水性能的影响规律。结果表明:随着SAHBPE-3含量从0增至30wt%,SA-HBPE-3/WPU胶膜的吸水率降至6.63%,涂覆处理织物的静态水接触角升至135.3°。SA-HBPE-3的引入提高了SA-HBPE-3/WPU胶膜的耐水性和涂覆织物的拒水性。当SA-HBPE-3含量为20wt%时,拒水效果达到最优值90分。

The waterborne polyurethane （WPU）was synthesized using hydroxy-terminated polydimethylsiloxane （number-average molecular weight is 2 000）,trimethylolpropane （TMP）,N-methyldiethanolamine （N-MDEA）and toluene diisocynate （TDI）etc.as raw materials.To introduce the hydrophobic branched chain,hydroxy-terminated hyperbranched polyesters were modified by stearic acid,hyperbranched polyesters end-capping with stearic acid were obtained.The composites consisting of WPU and stearic acid modified hyperbranched polyesters （SA-HBPE-3 ） were compounded and appled to fabric.The structures of WPU and SA-HBPE-3 before and after modification were characterized by infrared spectroscopy.The effect laws of SA-HBPE-3 content on water resistance,surface energy and water repellents of SA-HBPE-3/WPU film were studied by static water contact angle,water absorption rate and application test.The results show that when the SA-HBPE-3 content increases from 0 to 30wt%,the water absorp-tion rate of SA-HBPE-3/WPU film reduces to 6.63%,and the static water contact angle of coating fabric rises to 135.3°.The water resistance of SA-HBPE-3/WPU films and the water repellency of coating fabric increase with the addition of SA-HBPE-3.When the SA-HBPE-3 content is 20wt%,the waterproof performance evaluation gets the highest 90 points.