【作者】 占珊；

【导师】 余木火；

【作者基本信息】 东华大学 ， 材料学， 2007， 硕士

【摘要】 超支化聚合物与理想的树枝状大分子相比，其合成简便，可通过一步法或“准一步法”的本体聚合制备，因此价格相对较便宜。从使用角度来看，由于超支化聚合物的物理性能在一定程度上可与树枝状大分子相媲美，因此近年来，超支化聚合物越来越受到人们的关注。本文主要研究了超支化聚酯在尼龙6和PET加工过程中的应用。1、芳香族超支化聚酯在纺丝级尼龙6中的应用将芳香族超支化聚酯与纺丝级尼龙6在双螺杆挤出机中通过熔融共混的方式混合后，采用X-ray衍射、DSC研究了超支化聚合物对尼龙6结晶性能的影响，通过动态流变测试和熔融指数测试研究了尼龙6与超支化聚合物共混体系的流变性能，并进行了纺丝成型工艺试验及纤维的力学性能测试。X-ray衍射测试说明超支化聚合物的加入可使尼龙6的晶型发生变化，γ-晶型增强，α-晶型略有减弱。DSC研究表明，超支化聚合物的加入对尼龙6的结晶温度、结晶起止温度以及结晶峰半高宽均未产生明显影响，但有利于提高尼龙6的结晶速率。超支化聚酯的加入使得尼龙6的熔体流动速率明显提高，因此尼龙6／HBP共混物的加工温度比纯尼龙6有明显降低，这对防止尼龙6纺丝过程的聚合物热解和碳化将是一种有效的解决方案。2、芳香族超支化聚酯在瓶级PET中的应用将芳香族超支化聚酯与瓶级PET在双螺杆挤出机中通过熔融共混的方式混合后，采用非等温DSC、X-ray衍射及偏光显微镜研究了超支化聚合物对PET结晶性能的影响，采用扫描电镜观察了超支化聚酯在PET基体中的分散情况，并进行了注塑成型工艺试验及注塑样品的力学性能测试。结果究表明，超支化聚合物的加入对PET的结晶温度、结晶度、成核机理以及结晶速率都有一定影响，但对PET的熔点没有影响，进一步的X-ray衍射及偏光显微镜测试发现PET晶粒大小也有明显减小。超支化聚酯在PET基体中能够均匀分散，尺寸在几十到几百纳米之间。超支化聚合物的加入对PET注塑样条的力学性能没有明显影响。更多还原

【Abstract】 Hyperbranched polymers have attracted considerable and increasing interests during recent years because of their unique properties. Unlike dendrimers prepared by stepwise synthesis, hyperbranched polymers need a simple preparation process. Owing to the unique structure and properties, hyperbranched polymers has been used in many fields, such as blending, coating curing agent, composite material modification etc.1. Study on the aromatic hyperbranched polyesters used as processing additives in nylon 6 melt spinning processThe synthesized aromatic hyperbranched polyesters with different contents were blended with nylon 6 in a twin-screw extruder. The effects of hyperbranched polyesters on the crystallization behavior of nylon 6 were investigated using wide-angle X-ray diffraction (WAXD) and DSC methods. WAXD results indicated the crystal forms of nylon 6/hyperbranched polyesters were changed compared with those of pure nylon 6. In the blends,γ-crystal form content was more than that in pure nylon 6, and theα-crystal form content was a little less than that in pure nylon 6. DSC results showed that the blends had a little effect on the crystallization temperature, but the crystallization rate was improved compared with pure nylon 6. Owing to the decrease of the melt viscosity of nylon 6/HBP blends, the melt spinning temperatures of blends could be decreased dramatically, therefore the thermal degradation of nylon 6 could be reduced.2. Study on the aromatic hyperbranched polyesters used as processing additives for PET used as bottleThe synthesized aromatic hyperbranched polyesters with different contents were blended with PET in a twin-screw extruder. The effects of hyperbranched polyesters on the crystallization behavior of PET were investigated using non-isothermal DSC, wide-angle X-ray diffraction (WAXD) and polarizing microscopy (POM). The results showed that the hyperbranched polyesters had a certain effect on the crystallization temperature, crystallinity, crystallization rate and nuclear mechanism of PET, but had no effect on the melt point. Furthermore, small crystallites were observed by WAXD and POM. SEM micrographs showed the homogeneous dispersion of hyperbranhced polyesters in scale of tens to hundreds of nano-meters in PET matrix. The addition of hyperbranched polymer had no effect on the mechanical of PET.更多还原