毕业论文-聚醚型聚氨酯超支化聚酯互穿聚合物网络的形态和力学性能.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，并用正己酸、十二酸、十八酸对其进行端基改性，采用红外光谱（FTIR）、核磁（1H NMR）、凝胶渗透色谱（GPC）、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表征，发现超支化聚酯的端羟基已成功被长链烷基所取代。随着烷烃链长度的增加，分子量随之增大，超支化聚酯越容易结晶。为了改善聚醚型聚氨酯弹性体的力学性能，运用互穿聚合物网络技术，将烷基酸改性的超支化聚酯引入到聚醚型聚氨酯网络中。结果表明，相比于空白胶片，PU/HBP IPN体系的力学性能有了一定的提高，AFM分析表明，HBP-C6和HBP-C12的加入使得聚氨酯硬段相畴减小，微相分离程度降低；HBP-C18相畴呈颗粒状，使得互穿程度更高，力学性能更好。高含量的HBP-C18加入后，随着其用量的增加，互穿网络胶片的拉伸强度和断裂伸长率均呈现出先增大后减小的趋势，加入30%的HBP-C18时IPN体系的力学性能最好，具有典型的互穿网络力学性能的特点；采用“准一步法”和“一步法”合成端十八烷基超支化聚酯，分别与聚氨酯形成互穿网络，力学测试结果表明，前者的力学性能优于后者，“准一步法”合成的端十八烷基超支化聚酯分子量分布更窄，剪切变稀更为明显，因而自身链缠结更显著，形成的互穿网络结构较为完善，力学性能更优。

关键词：聚氨酯；超支化聚酯；互穿聚合物网络；微相结构；力学性能；原子力显微镜

Morphology and Mechanical properties of PU/hyperbranched polyester IPN

Abstract：Alkyl-terminated hyperbranched polyesters based on 1,1,1-trimethylolpropane as core and 2,2-bis(hydroxymethyl)propionic acid as branched monomer were end-capped with three different alkyl acids. Alkyl chain lengths ranging from six to eighteen carbons were used. The initial and modified polymers were characterized by Fourier transform infrared spectrum (FTIR), nuclear magnetic resonance spectroscopy (1H NMR), gel permeation chromatography (GPC), differential scanning calorimeter (DSC) and rotary rheometer to investigate the effects of the length of alkyl chains on thermal and rheological properties. The results indicated that the length of alkyl chains greatly influenced the properties of these polymers. The results of FTIR and 1H NMR showed that hyperbranched polymers with hydroxyl end-groups were modified in a high yield process. Longer alkyl chains as terminal groups induced further crystallization. In order to improve mechanical properties of polyether polyurethane elastomer, interpenetrating polymer network (IPN) modification technique was introduced. Results showed that mechanical properties of IPN were improved a little when the content of HBP was low, compared with control sample. After adding HBP-C6 or HBP-C12, the phase domain of the hard segment of PU was reduced, which proved that micro-phase separation was reduced. The phase domain of HBP-C18 was granular, which made the more entanglements formed in network. When the content of HBP-C18 was high, both the tensile strength and the elongation at break of IPN increased first and then decreased. When the content of HBP-C18 was 30%, the best mechanical properties were reached in IPN. The tensile strength was 1.76 times than that of PU, and the elongation at break was as high as 2055%, 7.56 times than before. These IPN films showed typical mechanical properties of IPN. The effect of synthesis method of HBP-C18 such as pseudo one-pot procedure and one-step method on mechanical properties of IPN was also studied. The results showed that the former performed better mechanical properties. The molecular weight distribution of hyperbranched polyester synthesized by pseudo one-pot procedure was narrower, and the shear-thinning behavior of pseudoplastic fluid was more apparent. Because of their own chain entanglements, better mechanical properties were performed.

Key words：polyurethane (PU); hyperbranched polyesters (HBP); interpenetrating polymer networks (IPN); mechanical properties; atomic force microscope (AFM)

目  录

摘要······································································································I

目录······································································································Ⅲ

术语表·····································································································V

1 绪论·····································································································1

1.1聚氨酯弹性体························································································1

1.1.1聚氨酯弹性体简介················································································1

1.1.2聚氨酯弹性体的结构与性能···································································2

1.2互穿网络聚合物增强聚氨酯弹性体·························································2

1.2.1互穿网络聚合物····················································································2

1.2.2互穿网络聚合物的结构形态·····································································3

1.2.3互穿网络聚合物的研究进展·····································································4

1.3超支化聚合物·························································································6

1.3.1超支化聚合物的结构··············································································6

1.3.2超支化聚合物的性能··············································································6

1.4本课题的研究目的与意义··········································································7

2 端烷基超支化聚酯的合成及表征········· ·····················································9

2.1 前言····································································································9

2.2 实验部分·····························································································9

2.2.1 实验原料 ·························································································9

2.2.2端烷基超支化聚酯的合成 ·····································································9

2.2.3端烷基超支化聚酯的提纯 ·····································································10

2.2.4实验仪器及测试条件 ···········································································11

2.3结果讨论 ····························································································11

2.3.1结构表征 ··························································································11

2.3.2相转变行为························································································13

2.3.3稳态流变性能 ····················································································15

3端烷基超支化聚酯对聚醚型聚氨酯弹性体力学性能及形态的影响························16

3.1 前言···································································································16

3.2 实验部分·····························································································16

3.2.1实验原料····························································································16

3.2.2胶片制备····························································································16

3.2.3 实验仪器及测试条件··········································································· 16

3.3结果与讨论···························································································17

3.3.1低用量时超支化聚酯对聚氨酯弹性体力学和形态的影响································17

3.3.2高用量时超支化聚酯对聚氨酯弹性体力学和形态的影响···························19

3.3.3合成方法对PU/HBP-C18互穿聚合物网络力学性能的影响···························22

4 结论·································································································25

参考文献······························································································26

致谢····································································································29