SBA15-g-HBPE的制备、表征及其对PEO基聚合物电解质膜的改性作用研究

Hyperbranched Polyethylene-grafted SBA15 Silica: Preparation, Structural Characterizations and Its Modification Effect on PEO-based Polymer Electrolyte Membrane

首先通过偶联剂3-丙烯酰基氧基丙基三氯硅烷对SBA15表面进行预处理,随后通过所得SBA15表面的丙烯酰基与α-二亚胺钯催化剂1进行成环反应,将催化剂1共价负载于SBA15孔道表面;进一步在乙烯压力1 atm和35°℃下催化乙烯在SBA15孔道表面接枝聚合,获得表面超支化聚乙烯(HBPE)接枝的SBA15(SBA15-g-HBPE);分别通过热重分析(TGA)、红外光谱(FT-IR)、小角X射线衍射(SAXRD)和透射电子显微镜(TEM)技术对改性前后SBA15的结构进行了表征,结果表明:通过所述工艺可实现HBPE在SBA15孔道表面共价接枝,接枝后SBA15仍保留完整孔道结构。在此基础上考察了所得SBA15-g-HBPE对聚氧乙烯(PEO)基聚合物电解质膜的改性作用,与改性前SBA15相比,SBA15-g-HBPE填充体系具有更优的离子导电性能,当填充15 phr的SBA15-g-HBPE8h,所得PEO基聚合物电解质膜的室温离子导电率较未填充体系提高近43倍。

Surface modification of pristine SBA15 silica was first performed with a coupling agent, 3-acryloxypropyltrichlorosilane, to give the SBA15 silica covalently tethered with acryloyl groups （Acryl-SBA15）. Then reaction between the Acryl-SBA15 silica with the Pd-α-diimine catalyst （1） was carried out to give a Pd-α-diimine catalyst covalently immobilized on the SBA15 silica （Pd-SBA15）. Ethylene polymerizations were further carried out with the resulting Pd-SBA15 at an ethylene pressure of 1 atm and 35 oC and a series of HBPE-grafted SBA15 silicas were obtained. Characterizations on various silicas were performed by means of thermogravimetry analysis （TGA）, fourier-transformed infrare spectra （FT-IR）, small-angle X-ray diffraction （SAXRD） and high-resolution transmission electron microscopy （HRTEM）. It is well confirmed that HBPE can be uniformly grafted within the mesopores of SBA 15 silica. The modification effect of the resulting SBA15-g-HBPE on PEO-based polymer electrolyte membrane was also investigated. It is found that the HBPE-grafted SBA15 silica shows a considerably increased ability in improving the ionic conductivity of PEO-based polymer electrolyte membrane as compared to the pristine SBA15 silica. The ionic conductivity at room temperature increased by 43 times for the membrane filled with 15 phr SBA15-g-HBPE8h as compared to the one without containing filler.