【作者】 张坤；

【导师】 朱美芳；

【作者基本信息】 东华大学 ， 材料加工工程， 2011， 硕士

【摘要】 高聚物基纳米复合树脂的研制及其应用研究是当前的热点,其中微纳尺度材料的引入对高聚物基体结构性能的影响备受学术界关注,也是产业界工艺调整优化的理论依据。本文以量大面广的聚对苯二甲酸乙二醇酯(polyethylene terephthalate, PET)为基体,以两种典型微纳尺度功能材料：载银磷酸锆抗菌功能材料和原位生成片层状钛系有机化合物作为添加相,通过非等温结晶等方法系统研究了该两种材料的的引入对聚酯基体热性能、结晶行为、流变行为等的影响；通过2D-WAXD表征分析了片状钛系有机化合物在加工成型过程中的取向趋势；通过SEM、TEM、AFM、FTIR、13C NMR和MALLDI-TOF-MS等手段表征了从复合树脂中分离出的片状钛系有机化合物的形貌和结构,进一步提出了其原位形成机理；研究了PET/载银磷酸锆复合树脂的纺丝成形性能,表征了所得纤维的力学和抗菌等性能；初步探索了纤维加工成形中超分子结构变化。得到了如下主要结论：1.载银磷酸锆在PET基体中分散比较均匀,粒径在1μm左右；磷酸锆的引入对PET树脂的熔点以及热降解温度影响不大,对PET的晶型也没有影响,但使PET的结晶能力有所提高。载银磷酸锆的引入,使得PET的复数黏度下降,原因可能是因为磷酸锆的引入减少了PET分子链之间的缠结,导致黏度的下降。2.原位引入的钛系有机物均匀分散在PET基体中,呈片状分布,厚度约120 nm,长和宽约500 nm。钛系有机物的引入对PET基体的分子量及其分布、热降解性能、熔点和结晶行为无明显影响。复合树脂的WAXD图谱中在8-12°出现了新的衍射峰,表明该钛系有机物是结晶的,并且其结构区别于已有的纳米Ti02的结晶结构。引入钛系有机物的复合树脂表现出有趣的流变特性：复合树脂的表观粘度在比较低的剪切速率下(100S-1),高于空白PET,但在高剪切速率下,低于空白PET。检测并分析了钛系有机物沿树脂、薄膜铸片和双向拉伸薄膜不同侧面入射时的2D-WAXD衍射图谱,发现片状钛系有机化合物在薄膜中呈平躺分布。分析FTIR、13C NMR和MALLDI-TOF-MS图谱表明,钛系有机物是钛系前驱体与合成PET的原料PTA和EG反应的产物,为单斜晶系的片晶。3.深入研究了两种不同微纳米粒子的引入对于PET结晶行为的影响。利用Jeziorny法研究了非等温结晶的初级结晶阶段,并计算了Avrami指数在3-4.5之间。研究发现Jeziorny法以及Mo法可以很好的模拟两种不同复合体系的非等温结晶动力学,但是Ozawa法对于模拟PET/磷酸锆体系出现偏差,可以很好地描述PET/Ti系复合材料。三种不同的处理方法都表明微纳米粒子的引入对于PET的结晶均有一定促进作用,加快了PET的结晶速率。4.PET/磷酸锆复合树脂在加工温度280-290℃之间具有很好的可纺性,在卷绕速度为800m/min, 1000m/min,1200m/min时,纺丝过程连续,随着纺丝速度增加,PET及其复合初生纤维的取向度增大。磷酸锆的引入对于PET的纤维取向度影响不大。磷酸锆的引入,使得在相同的卷绕速度下,断裂强度先减小后增大。原因可能是因为磷酸锆的引入造成纤维表面的应力集中。最后对纤维的抗菌性能进行了测试,表明有很好的抗菌效果,且抗菌率可以达到90%。5.依据DSC、WAXD以及二维SAXS等实验手段,初步探讨了牵伸过程对PET纤维超分子结构的影响。纤维在经过热牵伸后,DSC测试出现了熔融双峰,而且玻璃化转变以及冷结晶峰消失,可能是由于牵伸后的分子链排入晶格的折叠方式发生变化引起的；WAXD结果显示,未经牵伸的纤维的(110), (100)以及(111)晶面消失,经过牵伸后的纤维又重新出现。经过Scherrer公式计算晶面尺寸,牵伸后纤维的晶面尺寸要大于牵伸前的晶面尺寸。通过二维小角散射结果计算,初生丝的相关距离a01小于原丝的相关距离,相关距离a02大于原丝的相关距离。牵伸后纤维的旋转半径要大于牵伸前的,原因可能是因为牵伸后分子链沿着牵伸方向取向造成的。更多还原

【Abstract】 The preparation of polymer based nanocomposites and its application has been considered as one of the most important research directions. The effect of the incorporation of micro-nano material on the properties of polymer matrix has attracted much attention in recent years. It can also direct the technology parameter during the processing.Polyethylene terephthalate (PET) is one of the most important polymer materials with high production and wide application. In present thesis, PET is adopted as matrix, and the other two typical micro-nano composites, zirconium phosphate loaded Ag+ and titanium organics, are adopted as additives to prepare PET based nanocomposites. The thermal properties, rheology behavior and crystallization behavior of both nanocomposites were studied by using DSC method, rheology analysis and isotherm non-isothermal crystallization kinetics. Particularly, for PET/ titanium organics composites, the orientation of titanium organics in PET matrix during processing has been investigated by using two-dimensional X-ray diffraction method. The structure and morphology of titanium organics separated from PET composites were also characterized through SEM, TEM, AFM,13C NMR and MALLDI-TOF-MS. Meanwhile, the possible formation mechanism of slice-like titanium organics during processing was also discussed here. For PET/zirconium phosphate loaded Ag+ composites, the spinning property was studied in a systematic way, and the mechanical properties as well as the anti-bacterial properties were examined. Finally, the supermolecular structure of the as-spun fibers and drawn fibers has also been studied in detail. The major results obtained are as follows:1. It is found the particles of zirconium phosphate disperse uniformly in PET matrix, with the size of about 1μm. The incorporation of zirconium phosphate induces a negligible effect on the melting temperature, the degradation temperature as well as the crystal form of PET matrix, while elevates the crystallization ability of PET matrix. The rheology properties of composites have been discussed by using dynamic rheometer analysis. The results show that the complex viscosity of composites is lower than that of pure PET. It is possibly related with the decrease of the macromolecular chain entanglements caused by the addition of zirconium phosphate.2. The in-situ formed titanium organics are dispersed uniformly in PET matrix in the form of slice-like, with the length, width and thickness of about 500nm,500nm and 120nm, respectively. The incorporation of titanium organics has little influence on the molecular weight and molecular weight distribution and the the melting temperature and the crystallization behavior of PET composites has little change compared with PET matrix. From the WAXD patterns, it is indicated that PET composite exhibits new diffraction peaks between 2θ=8°-12°, suggesting that the in-situ formed titanium organics have unique crystalline structure, which are different from the crystalline structure of TiO2 reported. However, there is an interesting phenomenon of rheology properties of PET/ titanium organics composites. The complex viscosity of composites is higher than that of pure PET at low shear rate (100S-1), while the complex viscosity of composites is lower than that of pure PET at high shear rate. This phenomenon is possibly related to the orientation of titanium organics. The orientation of titanium organics in PET resin, as-spun film and drawn film is studied in detail by two-dimensional X-ray diffraction method, and the results show that the slice-like titanium organics are leveled off in PET matrix and the crystalline structure of the titanium organics may be monoclinic. Moreover, it is found that the in-situ formed slice-like titanium organics are the reaction product of the titanium compound precursor with PTA and EG monomer which was characterized by FTIR,13C NMR and MALLDI-TOF-MS spectrum.3. The non-isothermal crystallization kinetics of PET based composites were investigated through DSC method. The non-isothermal crystallization data was analyzed by Ozawa, Jeziorny and Mo method, respectively. It is found that both the Jeziorny method and Mo method can describe the non-isothermal crystallization process of these two kinds of composites availably. Comparatively, the Ozawa method can not describe the PET/ zirconium phosphate composites quite well, while can describe the PET/ titanium organics composites. Anyway, the results indicate that the incorporation of both the titanium organics and zirconium phosphate could promote the crystallization rate of PET matrix.4. The spinning technology of PET/ zirconium phosphate composites was discussed. It is shown that the spinning ability of composites is good and continuous in the temperature range of 280～290℃, with the winding speed of 800m/min, 1000m/min and 1200m/min. The degree of macromolecule orientation of fibers was tested by using sound velocimeter instrument and the results show that the higher is the winding speed, the more orientation along drawn direction. Meanwhile, the incorporation of zirconium phosphate induces negligible effect on the orientation of PET composites. In addition, the stress at break of PET composites is decreased first followed by increasing again with increasing the content of zirconium phosphate, which is possibly related with the existence of the cracks and voids generated in PET matrix caused by addition of zirconium phosphate, leading to the decrease of the mechanical properties. Also, the results based on the preliminary bacterial test indicate that the PET/ zirconium phosphate composites fibers have good anti-bacterial ability, with anti-bacterial rate of about 90%.5. The effect of drawing on the crystallization and orientation during the fiber processing has been studied by using DSC, FTIR, WAXD and two-dimensional X-ray scattering methods. The DSC results show that there are two melting peaks existed in drawn fibers, while for as-spun fibers there is only one melting peak. Meanwhile, the glass transition and cold crystallization peak of drawn fibers disappear. It is suggested that the folding patterns of chain segments were change after drawing processing. The content of gauche conformation and trans-conformation of fibers was calculated and it is found that the content does not change obviously. From WAXD results we can see that the diffraction peaks corresponding to (110), (100), (111) crystal planes can not exhibit in as-spun fibers, whereas these peaks exhibit in drawn fibers. According to Scherrer equation, the crystal sizes were calculated and it is shown that the crystal sizes of drawn are larger. Finally, the correlation distance and the gyration radius of fibers were calculated in the aid of two-dimensional X-ray scattering method. It is indicated that correlation distance a01of drawn fibers is decreased, wheraes a02 is increased. However, the gyration radius of drawn fibers is larger than that of as-spun fibers, suggesting that the macromolecular chains of drawn fibers were stretched more dramatically.更多还原