生物基异山梨醇改性磺酸盐水性聚氨酯的制备及性能

Preparation and properties of bio-based isosorbide modified waterborne sulfonate polyurethane

以异佛尔酮二异氰酸酯(IPDI)、聚碳酸酯二元醇(PCDL)、季戊四醇三丙烯酸酯(PETA)为主要原料,以自制的含磺酸基的低聚物聚酯二元醇(SO_(3)–2OH)为亲水单体,二羟甲基丁酸(DMPA)作为亲水扩链剂,合成了含磺酸基的聚氨酯预聚物,再采用生物基二元醇──异山梨醇(IS)对其进行改性,制备了可紫外光固化的异山梨醇改性磺酸盐水性聚氨酯(UV-SIWPU)乳液。通过傅里叶变换红外光谱仪(FT-IR)、紫外可见近红外分光光度计(UV-VIS-NIR)、凝胶渗透色谱(GPC)、光学接触角测量仪(OCA)等仪器对该乳液及其涂膜的结构、形貌和性能进行了分析。结果表明:当SO_(3)–2OH含量为20%,IS含量为75%时,所制备的UV-SIWPU涂膜的综合性能优异:水接触角为23.2°,吸水率为11.6%,在水中浸泡7 d后不泛白、不脱落,耐水性较好,拉伸强度为6.5 MPa,断裂伸长率为253%,铅笔硬度达到2H,在550 nm处的透光率达到96.0%,热稳定性和防雾性能良好。

A polyurethane prepolymer containing sulfonic acid groups was synthesized from isophorone diisocyanate(IPDI),polycarbonate diol(PCDL),pentaerythritol triacrylate(PETA)with a home-made polyester diol oligomer containing sulfonic acid groups(SO_(3)–2OH)as a hydrophilic monomer and dimethylolbutyric acid(DMPA)as a hydrophilic chain extender,and then modified with isosorbide(IS,a bio-based diol),forming a ultraviolet-curable isosorbide-modified sulfonate-containing polyurethane(UV-SIWPU)emulsion.The structure,morphology,and properties of the emulsion and its film were analyzed by using Fourier-transform infrared spectrometer,ultraviolet–visible–near infrared spectrophotometer,gel permeation chromatography,optical contact angle meter,and other instruments.The results showed that the UV-SIWPU film prepared with SO_(3)–2OH 20%and IS 75%had excellent basic properties:water contact angle 23.2°,water absorption rate 11.6%,tensile strength 6.5 MPa,elongation at break 253%,pencil hardness 2H,and light transmittance at 550 nm 96.0%.It had not only good water resistance,which was shown by the fact that no whitening or fall-off occurred after immersion in water for 7 days,but also good thermal stability and anti-fog performance.