聚对苯二甲酸乙二醇酯/碳酸钙纳米复合材料的制备和表征

以聚乙二醇磷酸酯1000为表面处理剂, 采用碳化法合成了方解石型碳酸钙纳米粒子, 进一步制备了聚对苯二甲酸乙二醇酯/碳酸钙纳米复合材料. 采用透射电子显微镜(TEM)、 X射线衍射(XRD)、 傅里叶变换红外光谱(FTIR), 场发射扫描电子显微镜(FESEM)和热重分析(TGA)对样品进行了分析. 结果表明, 聚乙二醇磷酸酯1000成功地修饰到碳酸钙的表面, 并得到平均直径为60 nm, 形貌为立方体的纳米碳酸钙晶体. 与碳酸钙(空白)样品相比, 表面处理碳酸钙的复合材料表现出更好的分散性和热稳定性. 采用Friedman方法计算了复合材料热分解的活化能. 聚对苯二甲酸乙二醇酯、 聚对苯二甲酸乙二醇酯/空白碳酸钙和聚对苯二甲酸乙二醇酯/表面处理碳酸钙的活化能分别为200.58, 214.86和219.50 kJ/mol, 进一步说明了表面处理碳酸钙更好地改善了聚对苯二甲酸乙二醇酯的热稳定性.

Preparation and Characterization of Poly(ethylene terephthalate)/Calcium Carbonate Nanocomposites

In order to improve the dispersion and increase the compatibility between nanoparticles and poly(ethylene terephthalate)(PET) matrix, calcium carbonate(CaCO3) nanoparticles were successfully prepared via a carbonization route with polyethylene glycol phosphate 1000(PGP) as the modifying agent. PET/CaCO3 nanocomposites were prepared by further in situ polymerization. The products were characterized by transmission electron microscope(TEM), X-ray powder diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), field emission scanning electron microscopy(FESEM) and thermo gravimetric analysis(TGA). It was found that PGP was successfully modified on the surface of CaCO3. Compared to the nanocomposite filled with the blank CaCO3, a significant improvement in thermal stability and dispersion was observed with the addition of 0.2%(mass fraction) PGP of the modified CaCO3. Friedman method was used to investigate activation energies of nanocomposites during thermal decomposition. The average of activation energies for PET, PET/blank CaCO3 and PET/modified CaCO3 were 200.58, 214.86 and 219.50 kJ/mol, respectively, indicating the modified CaCO3 incurred better thermal stability of PET.