刚性棒状聚电解质分子复合材料的研究

发布时间：2018-03-17 13:52

本文选题：分子复合材料　切入点：刚性棒状聚电解质　出处：《浙江大学》2015年硕士论文　论文类型：学位论文

【摘要】：分子复合材料是以刚性棒状大分子作为增强体、柔性聚合物为基体的高分子复合材料。分子复合材料的概念自1979年出现后便受到广泛关注。由于具有较大的长径比、高强度、高模量及高耐热性等一系列优点,刚性棒状大分子是复合材料理想的增强体。然而,由于刚性大分子与柔性基体的热力学不相容性,需通过分子设计引入化学或物理相互作用使相容性提高。本文合成了磺化芳香族聚酰胺及聚席夫碱,并将其作为刚性棒状大分子引入聚乙烯醇(PVA)及海藻酸钠(SA)基体中,研究复合物的结构与性能。(1)通过界面缩聚法合成磺化聚对苯二甲酰对苯二胺(sPPTA)及磺化聚对苯二甲酰联苯二胺(PBDT),用溶液浇膜法制备了PVA/sPPTA、PVA/PBDT及SA/PBDT复合材料,研究了sPPTA及PBDT在柔性基体中的分散状态及其对复合材料的耐热性及力学性能的影响。透射电镜及X射线衍射等结果表明,当含量较低时,sPPTA在PVA基体中分散良好,且使复合材料的拉伸强度明显提高。当sPPTA添加量为5 wt%时,sPPTA/PVA复合材料的拉伸强度可达1694±13MPa,比纯PVA强度增加约54%。随着sPPTA含量继续增加,可以观察到其在PVA基体中以微纤形式存在于基体中,并且对PVA的增强效果超过了多壁碳纳米管(MWNTs),气相生长碳纤维(VGCFs)及纳米金刚石,且制备方法简便。而PVA/PBDT复合材料中则出现PBDT的分子聚集现象,且增强效果不如sPPTA明显。另一方面,sPPTA无法溶解于SA溶液中,而PBDT则可与SA形成复合膜。扫描电镜结果表明PVA/PBDT体系出现相分离,但由于PBDT相与SA基体的结合力较强,能够有效传递应力,所以增强效果依然显著。当PBDT含量为10 wt%时,其拉伸强度可达944±10 MPa,比纯SA膜强度增加了约67%。(2)通过界面缩聚法合成了磺化芳香族聚席夫碱(PSB),用溶液浇膜法制备了PVA/PSB分子复合材料。研究了PSB在PVA中的分散状态及PVA/PSB分子复合材料的耐热性及力学性能。透射电镜,X射线衍射及偏光显徽镜等结果表明PSB在PVA中分散良好,在低PSB含量下未发现聚集现象。PVA/PSB-13wt%的拉伸强度达1544±8 MPa,约比纯PVA增加了40%,随着PSB继续增加,则出现PSB聚集体,力学性能下降。
[Abstract]:Molecular composite is a kind of polymer composite with rigid rod macromolecule as reinforcement and flexible polymer as matrix. The concept of molecular composite has attracted much attention since its appearance in 1979. A series of advantages, such as high modulus and high heat resistance, show that rigid rod-like macromolecules are ideal reinforcements for composite materials. However, due to the thermodynamic incompatibility between rigid macromolecules and flexible matrix, In this paper, sulfonated aromatic polyamides and polySchiff bases were synthesized and used as rigid rod-like macromolecules in polyvinyl alcohol (PVA) and sodium alginate (SA) matrix. The structure and properties of the composite were studied. (1) the sulfonated poly (terephthalyl p-phenylenediamine) and sulfonated poly (terephthalylbiphenylene diamine) PBDTT were synthesized by interfacial Polycondensation method. PVA / s PPTA / PVA / P / DT and SA/PBDT composites were prepared by solution casting method. The dispersion state of sPPTA and PBDT in the flexible matrix and their effects on the heat resistance and mechanical properties of the composites were studied. The results of transmission electron microscopy and X-ray diffraction showed that the dispersion of sPPTA and PBDT in the PVA matrix was good when the content was low. When the content of sPPTA was 5 wt%, the tensile strength of the composite could reach 1694 卤13MPa, which was about 54% higher than that of pure PVA. It can be observed that it exists in the matrix of PVA in the form of micro-fiber, and the reinforcement effect on PVA is better than that on multi-walled carbon nanotubes (MWNTs), gas grown carbon fibers (VGCs) and diamond nanocrystalline. On the other hand, the molecular aggregation of PBDT in PVA/PBDT composites was not as good as that of sPPTA. On the other hand, PBDT could not be dissolved in SA solution. PBDT can form composite membrane with SA. SEM results show that phase separation occurs in PVA/PBDT system, but because of the strong binding force between PBDT phase and SA matrix, the strengthening effect is still remarkable. When the content of PBDT is 10 wt%, the strengthening effect is still remarkable. The tensile strength of the composite was 944 卤10 MPA, which increased the strength of pure SA film by 67.2%) the sulfonated aromatic poly (Schiff base) PSBs were synthesized by interfacial Polycondensation. The PVA/PSB molecular composites were prepared by solution casting method. The dispersion state of PSB in PVA was studied. Heat resistance and mechanical properties of PVA/PSB molecular composites. The results of transmission electron microscope X-ray diffraction and polarizing microscope show that PSB is well dispersed in PVA. The tensile strength of PVA / PSB-13wt% was 1544 卤8MPa under low PSB content, which was about 40% higher than that of pure PVA. With the increase of PSB, the aggregation of PSB appeared and the mechanical properties decreased.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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