【作者】 何宏；

【导师】 龙柱；

【作者基本信息】 江南大学 ， 制浆造纸工程， 2013， 博士

【摘要】 近年来，利用无机粒子对高分子聚合物进行改性，制备一般工程材料所不具有的优异性能成为复合材料的研究重点。传统的塑料聚苯乙烯（PS）由于具有良好的透明性、透气性等性能在包装材料及传感领域应用广泛，但也存在不可降解的缺点；在众多生物可降解材料中，聚己内酯（PCL）、聚羟基脂肪酸酯（PHA）和聚丁二酸丁二酯（PBS）共聚物（PBSA）由于其良好的力学性能、生物降解性和生物相容性受到了人们的关注，PBSA具有成本低、良好的可熔融加工性能等特点；但是PCL熔点低、稳定性差、受力容易变形等缺陷限制了它的广泛应用；PHA则由于其生产成本高、可加工的温度范围窄和脆性高等许多缺点，也使其应用范围受到了限制。本文概述了纳米SiO₂及铼配合物在制备聚合物复合材料的研究进展及应用情况，并分别利用它们掺杂高分子聚合物，制备了具有良好力学性能、加工性能和光学稳定性的复合材料。首先利用PCL良好的生物相容性和降解性能，与PBSA及PHA的单体共聚酯Poly（3HB-co-4HB）共混制备聚酯复合材料，克服了单一聚酯材料的性能缺点，然后用改性后的纳米SiO₂分别对两种复合材料进行填充改性，制备了性能优越的新型生物降解纳米复合材料，并研究他们的力学性能、结晶性能、流变行为和降解性能等。最后，合成了带发光基团的铼配合物，并用它掺杂PS及PS/PCL基质制备复合纳米纤维，研究了他们的光物理性能。主要内容和结论如下：（1）采用熔融共混挤出法制备PCL/PBSA复合降解材料。利用DSC、电子万能拉力机、SEM、旋转流变仪（AR-G2）对其微观结构、结晶、动态力学性能以及流变行为进行了研究。在PCL/PBSA（40/60）时，产生了相反转，复合材料的拉伸强度最大，断裂伸长率较高，力学性能较好。随着PBSA含量的增加，PCL结晶的起始温度逐渐提高，结晶峰温度也提高了2.5°C；结晶最终完成的温度也相应地从28.7°C提高到32.6°C。流变结果表明随着角频率的增加，复合材料的G和G″均单调增加，PBSA含量提高，共混体系的储能模量出现先减小后增大的趋势。（2）制备了PCL/PBSA/纳米SiO₂复合材料，纳米SiO₂含量分别为1、2、3、5wt%。利用FTIR、DSC、电子万能拉力机、SEM、旋转流变仪（AR-G2）对其微观结构、结晶、动态力学性能、分散性、降解性能以及流变行为进行了研究。红外光谱分析表明钛酸酯偶联剂改性纳米SiO₂，改性后的纳米SiO₂分散性很好。力学性能及SEM观察说明当纳米SiO₂含量在2%时，纳米SiO₂粒子分散较好，复合材料体系有最好的力学性能；当超过2%时，粒子容易产生团聚，导致应力集中，使得力学性能有所下降；流变行为分析显示强烈的剪切稀化行为。（3）制备了PCL/Poly（3HB-co-4HB）复合材料，并对复合材料进行了力学性能、热性能、降解及流变行为研究。结果表明：PCL/Poly（3HB-co-4HB）质量比为60/40时，断裂伸长率达到最大，而随着Poly（3HB-co-4HB）的加入，其拉伸强度、断裂伸长率及屈服强度性能呈明显下降趋势。降解性能分析表明失重率与时间长短和样品厚度有较大影响，均随着降解时间的增长，失重率越大，材料的力学性能越差；样品越厚，降解越缓慢。热分析说明Poly（3HB-co-4HB）的加入对PCL的结晶性能也产生较大影响，造成结晶温度的提高，结晶度的下降。流变行为研究表明聚合物共混物熔体流动性对温度的变化比较敏感，储能模量和损耗模量均随温度的升高而不同程度地降低。（4）用熔融共混法制备了纳米SiO₂/PCL/Poly（3HB-co-4HB）复合材料，并研究了偶联剂的加入量对复合材料体系的流动行为的影响。研究结果表明：当改性纳米SiO₂的含量达到4%时，缺口冲击强度达到最大，拉伸强度较大，同时还兼有较高的韧性；改性纳米SiO₂的加入，使得PCL/Poly（3HB-co-4HB）基体更易结晶，结晶速率也上升，过多的改性纳米SiO₂的加入，反而对结晶不利；一定剪切速率下，随着偶联剂含量的提高，体系的剪切粘度下降，且在低剪切速率下，剪切粘度下降的很快，呈现剪切稀化特征，而且材料的蠕变行为加剧，材料的稳定性差；改性纳米SiO₂的加入加快了复合材料的降解速度。（5）合成了一个磷光铼配合物，利用其掺杂PS及PS/PCL体系制备了复合纳米纤维，并研究了复合纳米纤维的光学稳定性、透气性、力学性能。研究结果表明，5.5%的掺杂浓度最优，灵敏度为4.14，光稳定性最好，没有发生光漂白现象；在加入PCL后制得的复合纤维不仅力学性能得到提高，同时保持较好的发光性能，且具有了生物可降解性，拓展了应用范围，有望应用于传感、包装和造纸防伪技术领域。更多还原

【Abstract】 In recent years，research of composite materials has focused on modifying the polymerwith inorganic particles to prepare material with excellent performance that generalengineering material fails to attain. Polystyrene （PS）, the traditional plastic, was widely used inpackaging material and sensing fields for its good transparency and permeability, but it is nondegradable. Among the broad biodegradable polymers family, poly （ε-caprolactone）（PCL）,Poly（Butylene Succinate Adipate）（PBSA）and polyhydroxyalkanoates （PHA） have received anuniversal attention for their good mechanical properties, biodegradability and biocompatibility.PBSA has the advantages of low cost, good processability. The application of PCL is restrictedby its low melting point, poor stability and deformation. The application range of PHA is alsolimited for its shortages such as high production costs, high fragility and narrow processingtemperature range.This paper summarizes the research progress and application situation of nano SiO₂andRe（I） in preparing composite. Doped with polymer respectively, they were used to preparematerials with good mechanical properties, processing properties and optical stability. First,with good biocompatibility and biodegradation, the PCL was blended with PBSA andPoly（3HB-co-4HB） to prepare polyester composites, which overcame weakness of singlepolyester. Second, PCL/PBSA and PCL/Poly（3HB-co-4HB） composites were modified bynano SiO₂so as to prepare a new biodegradable nano composite material with excellentperformance. Their mechanical properties, crystallization properties, rheological behavior anddegradation properties were analyzed. Finally, Re（I） with luminous groups were prepared andblended with PS and PS/PCL matrix to prepare composite nanofiber, and their photophysicalproperties were studied. The main contents and conclusions are as follows:Firstly, PCL/PBSA blends were prepared by mechanically melting mixing. Themicrostructure, crystallization, dynamic mechanical properties, and rheological behavior werestudied by DSC, the electronic universal tensile machine, SEM, rotary rheometer. When thequality of PCL/PBSA blend ratio was40/60, the tensile strength reached the maximum withrelatively high elongation and preferable mechanical properties. As the PBSA contentincreased, the initial temperature of the crystallization of PCL went up, the peak temperatureof the crystallization increased by2.5°C and the final crystallization temperature increasedfrom28.7°C to32.6°C. The rheological results showed that with angular frequency growing,storage modulus and loss modulus increased monotonically, PBSA content went up and thestorage modulus of the blend system decreased at first, then increased.Secondly, PCL/PBSA/nanoSiO₂blends were prepared with nano SiO₂content1,2,3,5wt%respectively. Microstructure, crystallization, dynamic mechanical properties, dispersion,degradation properties and rheological behavior were analyzed by FTIR, DSC, electronicuniversal tensile machine, SEM, rotary rheometer （AR-G2） The analysis of Infrared spectralshowed that coupling agent of organic titanate modified nano SiO₂and the modified SiO₂ nanoparticles dispersed well. Mechanical properties and SEM observation showed that whenthe content of nano SiO₂took up2wt%, nano SiO₂particles dispersed well with optimummechanical properties of the composite system. When the content was more than2%, thematrix particle agglomeration were prone to forming, leading to stress concentration andmechanical properties decreasing. Rheological behavior analysis indicated strong shearthinning behavior.Thirdly, PCL/Poly（3HB-co-4HB） composite was prepared, and the mechanical properties,thermal properties, degradation and rheological behavior of the composites were studied. Theresults showed that when PCL/Poly（3HB-co-4HB） mass ratio was60/40, elongation at breakreached the maximum. As the content of Poly （3HB-co-4HB） increased, the tensile strength,elongation at break and yield strength declined dramatically. Degradation analysis showedthat the weight loss rate was closely related to length of time and thickness of the sample. Asthe degradation time grew, the weight loss rate rise and the mechanical properties of thematerials declined. The thicker the sample was, the slower it degraded. Thermal analysisshowed that increase of Poly（3HB-co-4HB） also had a great effect on the crystallizationbehavior of PCL, leading to higher crystallization temperature and lower crystallinity. Studyon rheological behavior of polymer blends showed melt flow properties fluidity was sensitiveto temperature changes. As temperature increased, the storage modulus and loss modulusdecreased.Fourthly, PCL/Poly（3HB-co-4HB）/nanoSiO₂was prepared by melt blending. Theinfluence of coupling agent on the flow behavior of composite was studied. The resultsindicated that when the modified nano SiO₂content reaches4%, the notched impact strengthreached the maximum with tensile strength and toughness growing; The modified nano SiO₂facilitated the crystallization of PCL/Poly（3HB-co-4HB） matrix with the crystallization raterising dramatically; an excessive of modified nano SiO₂will block crystallization instead;Under a certain shear rate, as the content of coupling agent increased, shear viscosity of thesystem decreased. With a low shear rate, the shear viscosity decreased quickly and tended tobe shear-thinning, and at the same time, creep behavior of materials increased and stability ofthe material declined; the nano SiO₂accelerated the degradation of composites.Finally, A phosphorescent Re（I） was synthesized and compositiuie nanofiber wasprepared by doped PS and PS/PCL matrix. The optical stability, permeability and mechanicalproperties of the composite nanofiber material were studied. The results showed5.5%dopingconcentration was the optimum with sensitivity4.14, when light stability was best withoutbleaching phenomenon. The complex nanofiber with a small amount of PCL has bettermechanical properties of composite fiber, favorable luminescence property andbiodegradation, which can be applied in optical oxygen sensing field, packaging and anticounterfeit papermaking in the future.更多还原