水基阳离子聚氨酯/聚吡咯导电材料的原位制备与电阻性能

摘要

A series of waterborne cationic polyurethanes dispersions (CWPU) was prepared through prepolymer-ization method by reacting polyethylene glycol (PEG1000) and isophorone diisocyanate (IPDI) with N-methyl diethanol amine (MDEA) as chain extender. Then FeCl3 was employed as oxidant, therefore CWPU/polypyr-role (CWPU/PPy) conductive composite was prepared by in situ chemical oxidative polymerization of pyrrole (Py) in CWPU dispersions. Fourier infrared spectra demonstrated the presence of hydrogen-bonding interactions between CWPU and PPy. The average particle size of CWPU/PPy increased from 10. 61 to 30. 29nm compared with pure PU, and corresponding size distribution decreased from 0. 850 to 0. 346. It was also found that CWPU colloidal particles were uniformly encapsulating by PPy, displaying as spherical morphology, and no aggregation among particles was detected among particles. Results also showed that the surface resistivity of CWPU/PPy composite film surface decreased to 20Ω · cm when Py concentration was 20%, reaction temperature was 40 ℃ , reaction time was 2h and n(FeCl3)(Py) =2. 0.%以N-甲基二乙醇胺(MDEA)为扩链剂,聚乙二醇(PEG1000)、异佛尔酮二异氰酸酯(IPDI)为原料,通过预聚体法制备了系列水基阳离子聚氨酯分散液(CWPU).再以FeCl3为氧化剂,在CWPU中进行吡咯的原位化学氧化聚合制备聚氨酯/聚吡咯(CWPU/PPy)复合导电材料.红外光谱图表明PPy与CWPU分子间存在氢键缔合.经PPy改性后,CWPU/PPy的分散液的平均粒径由10.61nm增加至30.29nm,粒径分布系数由0.850下降至0.346.原位聚合过程中PPy能均匀包裹于CWPU胶粒表面,CWPU/PPy分散液胶粒呈球形结构,彼此间相互独立.实验结果亦表明,当Py浓度为20％、反应温度为40℃、反应时间为2h、n(FeCl3) (Py)=2.0时,CWPU/PPy复合薄膜的表面电阻率可达到20Ω·cm.