摘  要：以1,1,1-三羥甲基丙烷為核，2,2-二羥甲基丙酸為支化單體，對甲苯磺酸為催化劑，通過熔融縮聚法合成第三代端羥基脂肪族超支化聚酯，并用正己酸、十二酸、十八酸對其進(jìn)行端基改性，采用紅外光譜（FTIR）、核磁（1H NMR）、凝膠滲透色譜（GPC）、差示掃描量熱分析（DSC）以及旋轉(zhuǎn)流變儀對改性后產(chǎn)物的結(jié)構(gòu)和性能進(jìn)行表征，發(fā)現(xiàn)超支化聚酯的端羥基已成功被長鏈烷基所取代。隨著烷烴鏈長度的增加，分子量隨之增大，超支化聚酯越容易結(jié)晶。為了改善聚醚型聚氨酯彈性體的力學(xué)性能，運(yùn)用互穿聚合物網(wǎng)絡(luò)技術(shù)，將烷基酸改性的超支化聚酯引入到聚醚型聚氨酯網(wǎng)絡(luò)中。結(jié)果表明，相比于空白膠片，PU/HBP IPN體系的力學(xué)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疇減小，微相分離程度降低；HBP-C18相疇呈顆粒狀，使得互穿程度更高，力學(xué)性能更好。高含量的HBP-C18加入后，隨著其用量的增加，互穿網(wǎng)絡(luò)膠片的拉伸強(qiáng)度和斷裂伸長率均呈現(xiàn)出先增大后減小的趨勢，加入30%的HBP-C18時(shí)IPN體系的力學(xué)性能最好，具有典型的互穿網(wǎng)絡(luò)力學(xué)性能的特點(diǎn)；采用“準(zhǔn)一步法”和“一步法”合成端十八烷基超支化聚酯，分別與聚氨酯形成互穿網(wǎng)絡(luò)，力學(xué)測試結(jié)果表明，前者的力學(xué)性能優(yōu)于后者，“準(zhǔn)一步法”合成的端十八烷基超支化聚酯分子量分布更窄，剪切變稀更為明顯，因而自身鏈纏結(jié)更顯著，形成的互穿網(wǎng)絡(luò)結(jié)構(gòu)較為完善，力學(xué)性能更優(yōu)。

關(guān)鍵詞：聚氨酯；超支化聚酯；互穿聚合物網(wǎng)絡(luò)；微相結(jié)構(gòu)；力學(xué)性能；原子力顯微鏡

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  錄

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

目錄······································································································Ⅲ

術(shù)語表·····································································································V

1 緒論·····································································································1

1.1聚氨酯彈性體························································································1

1.1.1聚氨酯彈性體簡介················································································1

1.1.2聚氨酯彈性體的結(jié)構(gòu)與性能···································································2

1.2互穿網(wǎng)絡(luò)聚合物增強(qiáng)聚氨酯彈性體·························································2

1.2.1互穿網(wǎng)絡(luò)聚合物····················································································2

1.2.2互穿網(wǎng)絡(luò)聚合物的結(jié)構(gòu)形態(tài)·····································································3

1.2.3互穿網(wǎng)絡(luò)聚合物的研究進(jìn)展·····································································4

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

1.3.1超支化聚合物的結(jié)構(gòu)··············································································6

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

1.4本課題的研究目的與意義··········································································7

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

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

2.2 實(shí)驗(yàn)部分·····························································································9

2.2.1 實(shí)驗(yàn)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純 ·····································································10

2.2.4實(shí)驗(yàn)儀器及測試條件 ···········································································11

2.3結(jié)果討論 ····························································································11

2.3.1結(jié)構(gòu)表征 ··························································································11

2.3.2相轉(zhuǎn)變行為························································································13

2.3.3穩(wěn)態(tài)流變性能 ····················································································15

3端烷基超支化聚酯對聚醚型聚氨酯彈性體力學(xué)性能及形態(tài)的影響························16

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

3.2 實(shí)驗(yàn)部分·····························································································16

3.2.1實(shí)驗(yàn)原料····························································································16

3.2.2膠片制備····························································································16

3.2.3 實(shí)驗(yàn)儀器及測試條件··········································································· 16

3.3結(jié)果與討論···························································································17

3.3.1低用量時(shí)超支化聚酯對聚氨酯彈性體力學(xué)和形態(tài)的影響································17

3.3.2高用量時(shí)超支化聚酯對聚氨酯彈性體力學(xué)和形態(tài)的影響···························19

3.3.3合成方法對PU/HBP-C18互穿聚合物網(wǎng)絡(luò)力學(xué)性能的影響···························22

4 結(jié)論·································································································25

參考文獻(xiàn)······························································································26

致謝····································································································29