【作者】 王丽；

【导师】 罗发亮；

【作者基本信息】 宁夏大学 ， 化学工程（专业学位）， 2014， 硕士

【摘要】 本文首先通过双螺杆熔融挤出技术,研究了热塑性聚醚酯弹性体(TPEE)接枝马来酸酐(MAH)的熔融反应规律。通过傅里叶变换红外光谱(FTIR)的表征,说明MAH接枝到TPEE大分子链上,并采用酸碱滴定法测定了TPEE-g-MAH的接枝率,研究了配方和挤出工艺条件对TPEE-g-MAH接枝率和熔体流动速率的影响,从而得出制备TPEE-g-MAH产物比较适宜的配方和工艺条件为：DCP用量为0.35%,MAH用量为2%、挤出温度为190℃,螺杆转速为100r/min。然后通过双螺杆熔融挤出技术将PLLA和TPEE-g-MAH进行共混挤出制得PLLA/TPEE-g-MAH复合材料,并采用万能材料试验机、冲击试验机、热失重分析仪(TGA)、差示扫描量热计(DSC)、动态力学分析仪(DMA)、偏光显微镜(POM)、场发射扫描电子显微镜(SEM)、应力控制型流变仪研究了复合材料的力学性能、热性能、结晶行为、结晶形貌、断面形貌及流变性能。结果表明：随着TPEE-g-MAH含量的增大,复合材料的强度和模量逐渐下降,断裂伸长率和缺口冲击强度先增大后减小；复合材料的热稳定性有所降低；复合材料的玻璃化转变温度有所降低,其韧性有所提高,且结晶速率和结晶度均有所减小；POM测试表明PLLA/TPEE-g-MAH共混材料物仍呈现出典型的球晶形貌,且共混物的球晶尺寸相对PLLA有所增大,其球晶生长速率随温度的增大而逐渐增大；复合材料的冲击断面SEM照片显示随着TPEE-g-MAH含量逐渐增大,相界面开始变得模糊,加强了界面间的作用；PLLA/TPEE-g-MAH复合材料属于假塑性流体,TPEE-g-MAH的加入降低了复合材料的熔体粘度,使PLLA/TPEE-g-MAH体系的加工性能得到了改善。接着采用DSC研究了PLLA/TPEE-g-MAH复合材料的等温结晶动力学,结果表明复合材料的结晶基本符合等温结晶动力学Avrami方程,TPEE-g-MAH的加入减缓了PLLA分子链的结晶进程,降低了其结晶速率,且结晶速率随着结晶温度的降低而加快。采用nano-Al2O3和PLLA/TPEE-g-MAH共混制备出PLLA/TPEE-g-MAH/nano-Al2O3三元复合材料,并研究了不同nano-Al2O3添加量对其力学性能、热性能及结晶行为的影响。结果表明：加入nano-Al2O3的三元复合材料的热稳定性却有所降低,这与nano-Al2O3的团聚有关；少量nano-Al2O3的加入有利于提高复合材料的结晶程度;复合材料的强度及模量均随着nano-Al2O3含量的增加大体上呈下降趋势；断裂伸长率在nano-Al2O3含量为2%时达到最大143.51%,冲击强度在nano-Al2O3含量为4%时达到最大6.27KJ/m2。综合以上,当nano-Al2O3含量为1%时,三元复合材料具有良好的综合力学性能。更多还原

【Abstract】 In this thesis, Maleic anhydride (MAH) grafted thermoplastic polyester elastomer(TPEE) was firstly prepared using dicumyl peroxide(DCP) as initiator in the twin-screw extruder and characterized by Fourier transform infrared spectroscopy (FTIR). The results showed that MAH could be grafted onto TPEE macromolecular chains by using reactive extrusion methods. Moreover, The grafting degree of MAH on TPEE was determined by acid-base titration. The effects of extrusion process conditions, the amount of initiator and MAH on grafting degree and melt flow rate of TPEE-g-MAH were studied. The results showed that the optimal conditions were:DCP0.35%, MAH2%, the extrusion temperature190℃, the rotation speed of twin-screw100r/min.PLLA/TPEE-g-MAH alloy materials were prepared by twin-screw melt techno logy. The thermal properties, crystallization behavior, crystalline morphology, fracture surface and rheological properties were studied by universal testing machine, impact testing machine, thermal gravimetric analysis (TGA), differential scanning calorimeter (DSC), dynamic mechanical analyzer (DMA), polarized light microscopy (POM) and field emission scanning electron microscope (SEM), respectively. The results showed that the strength and modulus of the composite decreased with the increasing content of TPEE-g-MAH. The elongation at break and notched impact strength first increased then decreased with the increasing content of TPEE-g-MAH. The thermal stability, the glass transition temperature, crystallization rate and degree of crystallinity of the alloy materials decreases with addition of TPEE-g-MAH, respectively. POM tests showed that PLLA/TPEE-g-MAH materials still show a typical spherulitic morphology, and the spherulite size of PLLA in blends is larger than pure PLLA. PLLA spherulite growth rate in blends increases with temperature increases. The phase interface became blurred with TPEE-g-MAH content increases from the SEM photos. It has proved that the role of the interface strengthened. PLLA/TPEE-g-MAH alloy displays pseudoplastic fluid properties in reological analysis. With addition of TPEE-g-MAH, the melt viscosity of the alloy reduces, so the processing performance of PLLA/TPEE-g-MAH composites have improved.The isothermal crystallization kinetics of PLLA/TPEE-g-MAH composites were studied by DSC.The results showed that the composite materials were in line with isothermal crystallization kinetics Avrami equation mainly.The crystallization process of PLLA molecular chain and the crystallization rate reduced with the addition of TPEE-g-MAH, and the rate of crystallization increased with the crystallization temperature decreased.PLLA/TPEE-g-MAH/nano-Al2O3ternary composites were prepared by blending nano-Al2O3, PLLA and TPEE-g-MAH. The effects of amount of nano-Al2O3on its mechanical properties, thermal properties and crystallization behavior were studied. The results showed that the addition of nano-Al2O3decreased the thermal stability of PLLA/TPEE-g-MAH/nano-Al2O3composites.The reason was related to the reunion of nanoparticles.The degree of crystallinity of the composite materials improved with a little addition of nano-Al2O3。The strength and modulus of the composite materials decreased with increase of nano-Al2O3content;The elongation reach maximum143.51%when nano-Al2O3content is2%, and the impact strength reach maximum6.27KJ/m2when nano-Al2O3content is4%.Based on the above, the ternary composites have good comprehensive mechanical properties when the nano-Al2O3content is1%.更多还原