摘  要

本文采用濃硝酸酸化碳納米管，并通過正硅酸乙酯在碳納米管表面接枝大量羥基，然后通過加入硅烷偶聯(lián)劑KH550，形成表面被包覆的碳納米管；再以聚乳酸為主體、PHB為輔料、碳納米管為增強(qiáng)體,采用哈克密煉機(jī)制備PLA/PHB/碳納米管復(fù)合材料。通過紅外吸收光譜分析經(jīng)碳納米管的處理情況；采用電鏡掃描分析處理過碳納米管的分散情況以及積聚形態(tài)；采用拉伸測試、沖擊測試、靜彎曲測試來研究復(fù)合材料的力學(xué)性能；采用微型燃燒量熱計研究復(fù)合材料的熱穩(wěn)定性能；采用毛細(xì)管流變儀研究復(fù)合材料的流變性能；采用維卡軟化溫度測試儀測定復(fù)合材料的維卡軟化溫度。

通過碳納米管紅外光譜分析表明，經(jīng)過正硅酸乙酯和硅烷偶聯(lián)劑的綜合處理，在碳納米管表面上成功的接枝了大量的官能團(tuán)，并且表面包覆了有效地附著基團(tuán)。

力學(xué)性能研究表明，加入彈性體PHB之后，材料的拉伸強(qiáng)度、沖擊強(qiáng)度、斷裂伸長率提高，靜彎曲強(qiáng)度下降。再加入少量的碳納米管之后，復(fù)合材料的拉伸強(qiáng)度、沖擊強(qiáng)度和靜彎曲強(qiáng)度都有很大的提升，斷裂伸長率下降。但是增加碳納米管的組分，由于這是由于碳納米管的團(tuán)聚導(dǎo)致與復(fù)合材料界面粘結(jié)力下降，沖擊強(qiáng)度有所下降。

流變性能研究表明，聚乳酸加入PHB后，在低剪切速率下，體系的表觀粘度增加；在較高剪切速率下，體系的表觀粘度低于純聚乳酸的，說明加入PHB之后，體系的表觀粘度更受剪切速率的影響。在加入碳納米管之后，體系的表觀粘度增大，并且碳納米管含量越大，表觀粘度也越大。

熱穩(wěn)定性能研究表明，加入碳納米管之后，復(fù)合材料的熱釋放速率峰值有了較大的下降，并且熱釋放速率峰值對應(yīng)的時間也有所延遲。說明碳納米管的加入能夠提高聚乳酸的熱穩(wěn)定性。

    關(guān)鍵詞：聚乳酸； 聚3羥基-4羥基丁酸酯； 碳納米管； 復(fù)合材料； 

ABSTRACT

In this paper, used the nitric acid acidized carbon nanotubes, and through the tetraethyl orthosilicate(TEOS) in carbon nanotubes surface hydroxyl grafted a lot, and then through the join silane coupling agent KH550, the formation of a surface of carbon nanotubes was enshrouded;Again with poly lactic acid(PLA) as the main body, the PHB as the auxiliary materials, carbon nanotubes in order to strengthen the body, the tried for PLA/PHB/carbon nanotube composite materials by HAAKE.The infrared absorption spectral analysis had the carbon nanotubes treatment; By using scanning electron microscopy (SEM) analysis process of the dispersion of carbon nanotubes and accumulation form; Use a tensile test, impact test, static bending test to study the mechanical properties of composite; By micro burning calorimeter(MCC) study the thermal stability of the composite material performance; Capillary rheometry study the rheological properties of composite material can; Using vicat softening temperature tester(VST) of composite materials were vicat softening temperature.

Through the carbon nanotubes infrared spectral analysis indicates that, after TEOS and silane coupling agent comprehensive treatment in carbon nanotubes surface to the success of a large number of grafted functional group, and the surface coated with effectively attached to the group.

Mechanical properties research indicate that by elastomer PHB later, material of tensile strength, impact strength, elongation at break improve, static bending strength decline. Add a small amount of carbon nanotubes after, the tensile strength of the composite, impact strength and bending strength has greatly improved, elongation at break down. But the increasing of the carbon nanotubes components, because this is due to the reunion of carbon nanotubes in and the compound material interface bond drop, impact strength fell.

Include research shows that, PLA to join PHB, in low shear rate, apparent viscosity increases the system; In the higher shearing rate, apparent viscosity of the system of less than pure PLA, explain to join PHB after, the system will be more apparent viscosity shearing rate influence. In the join carbon nanotubes after, apparent viscosity increases the system, and the greater the content of carbon nanotubes, the greater the apparent viscosity.

Thermal stability study shows that, after join carbon nanotubes, composite materials of heat release rate peak has larger drops and heat release rate and the corresponding time also peak a delay. Explain the carbon nanotubes join can improve thermal stability of PLA.

Key words: PLA； P(3HB-co-4HB)； Carbon nanotubes； Composite

目    錄

1.前言 1

1.1 引言 1

1.2 聚乳酸概述 1

1.3 PHB概述 3

1.4 碳納米管概述 4

1.5 聚乳酸/PHB/碳納米管復(fù)合材料的制備 6

1.6 聚乳酸/PHB/碳納米管復(fù)合材料的研究現(xiàn)狀與展望 7

1.7 本課題研究的主要內(nèi)容 8

2.實(shí)驗(yàn)材料和方法 9

2.1 實(shí)驗(yàn)原料 9

2.2 實(shí)驗(yàn)儀器 9

2.3 碳納米管的純化和表面修飾 10

2.4 復(fù)合材料的制備 10

2.5 測試與表征 11

3.結(jié)果討論與分析 13

3.1 碳納米管的處理結(jié)果分析 13

3.2 力學(xué)性能測試 15

3.3 聚乳酸/PHB/碳納米管復(fù)合材料電鏡掃描斷面分析 19

3.4 流變性能測試 21

3.5 維卡軟換溫度測試 23

3.6 微型全自動量熱測試 24

參考文獻(xiàn) 26

致謝 29