端烷烃链对脂肪族超支化聚酯结晶性能和流变性能的影响.doc

摘  要：以1,1,1-三羟甲基丙烷为核，2,2-二羟甲基丙酸为支化单体，对甲苯磺酸为催化剂，通过熔融缩聚法合成第三代端羟基脂肪族超支化聚酯，并用十八酸对其进行端基改性，采用红外光谱（FTIR）、核磁（1H NMR）、X射线衍射（XRD）、差示扫描量热分析（DSC）以及旋转流变仪对改性后产物的结构和性能进行了表征，研究端烷烃链对脂肪族超支化聚酯结晶性能和流变性能的影响。结果表明，超支化聚酯的端羟基已成功被长链烷基所取代。超支化聚合物的结晶能力由于长链端烷烃的有序排列而得到明显提高。改性超支化聚酯的结晶能力主要取决于端基长链烷烃的数量，与端羟基含量的多少无关。通过旋转流变仪来表征超支化聚酯的流变性能，由于端烷烃链的缠结作用，超支化聚酯的线性粘弹区随着端基改性程度的增大而逐渐变短；由于端十八烷基的“内增塑”作用，使得改性后超支化聚酯的复数粘度值明显小于改性前；改性超支化聚酯的流变特性不遵循Cox-Merz方程，改性程度越大，表观粘度与复数粘度的偏离程度越大；端烷烃链数量的增多使得分子间逐渐发生了链缠结，相互作用力增加，粘度对剪切的依赖性增大，剪切变稀越明显；四种改性超支化聚酯的结晶温度接近，进一步证实了超支化聚酯的结晶确实是由长链端烷基的有序排列造成的，而非氢键的作用。

关键词：超支化聚酯；十八酸；结晶性能；流变性能；链缠结

Effect of the terminal alkyl groups on the crystallization and rheological properties of aliphatic hyperbranched polyesters

Abstract：Hyperbranched polyesters based on 1,1,1-trimethylolpropane as core and 2,2-bis(hydroxymethyl)propionic acid as branched monomer were end-capped with stearic acids. The initial and modified polymers were characterized by Fourier transform infrared spectrum(FTIR), nuclear magnetic resonance spectroscopy(1H NMR), x-ray diffraction(XRD), differential scanning calorimeter(DSC) and rotary rheometer to investigate the effects of alkyl chains on crystallization and rheological properties of aliphatic hyperbranched polyesters. The results indicated that the amount of alkyl chains greatly influenced the properties of these polymers. The results of FTIR and 1H NMR showed that hyperbranched polymers were modified successfully. The improvement of crystallization properties can by realized by the ordered arrangement of long alkyl chains. The ability of crystallization of the modified hyperbranched polyesters mainly depends on the amount of alkyl chains. The rheological properties of hyperbranched polyesters were determined by rotary rheometer. Because of the entanglement of alkyl-terminated chains, the LVE region became shorter gradually with the improvement of the degree of modification, and the complex viscosity of hyperbranched polyesters was significantly lower than before. The Cox-Merz rule did not hold for the hyperbranched polyester, and with the improvement of the degree of modification, the hyperbranched polyester showed deviations from the rule due to the long alkyl chains in the terminal groups. After modification, the long alkyl chains weaken the hydrogen bonds, which reduced the dependence of viscosity on shear. The relationship between the shear viscosity and shear rate was dependent on the chain entanglements.With the improvement of the degree of modification, chain entanglements became more serious. The crystallization temperature of four kinds of modified hyperbranched polyesters was close, which further confirmed that the improvement of crystallization properties of the hyperbranched polyester can be realized by ordering the arrangement of the long alkyl chains in the terminal groups.

Key words：hyperbranched polyester; stearic acid; crystallization properties; rheological properties; chain entanglements

目  录

摘要 I

目录 III

术语表 1

1绪论 2

1.1超支化聚合物 2

1.1.1超支化聚合物的结构 2

1.1.2超支化聚合物的合成 3

1.1.2.1 缩聚 4

1.1.2.2活性聚合 4

1.1.2.3多支化开环聚合 5

1.1.2.4离子型聚合 6

1.1.3 超支化聚合物的性能 6

1.1.3.1 溶解性 6

1.1.3.2 粘度 6

1.1.3.3玻璃化转变温度(Tg) 7

1.1.3.4流变学性质 7

1.1.3.5结晶性能 7

1.1.3.6 胶束特性 8

1.2 课题研究的目的和意义 8

2实验部分 9

2.1实验原料 9

2.2 超支化聚酯的合成 9

2.3 超支化聚酯的提纯 11

2.4 实验仪器及测试条件 11

2.4.1 红外(FTIR) 11

2.4.2 核磁(1H NMR) 11

2.4.3 广角X射线衍射(WAXD) 11

2.4.4 差示扫描量热分析(DSC) 12

2.4.5 流变测试 12

3结果与讨论 13

3.1 超支化聚酯的结构表征 13

3.2 超支化聚酯的结晶性能 15

3.3 超支化聚酯的热性能 16

3.4 超支化聚酯的流变性能 17

3.4.1线性粘弹区（LVE）的确定 17

3.4.2 频率扫描 18

3.4.3 温度扫描 22

3.5 改性超支化聚酯的缠结、松弛与结晶 22

4 结论 25

参考文献 26

致谢 30