基于NIPAM的水凝膠與有機(jī)凝膠的流變學(xué)性能研究
發(fā)布時(shí)間：2018-09-16 20:58
【摘要】：基于N-異丙基丙烯酰胺(NIPAM)的凝膠具有接近人類體溫的低臨界溶解溫度(LCST)。這種特性使其成為在給藥和生物醫(yī)學(xué)工程中有著應(yīng)用潛力的熱敏性聚合物凝膠材料。在許多用于表征凝膠的儀器中,流變儀是探究諸如凝膠、懸浮液、膠體等軟物質(zhì)材料的重要工具�？赏ㄟ^流變學(xué)表征凝膠的成膠溫度、LCST、多種力學(xué)性能以及對(duì)施加應(yīng)變的響應(yīng)等。在本論文中,我們合成了一系列基于NIPAM的水凝膠或有機(jī)凝膠并主要從流變學(xué)的角度研究這些凝膠的性能,本文的主要內(nèi)容如下:第一章介紹了基于NIPAM的凝膠材料、流變學(xué)以及流變儀的基本概念。第二章主要涉及在不同甲醇-水混合溶劑中合成的NIPAM與NEAM(N-乙基丙烯酰胺)無規(guī)共聚水凝膠。采用溫度掃描和單軸壓縮測試表征它們的LCST和力學(xué)性能。LCST與合成時(shí)的溶劑條件無關(guān)。在水占主導(dǎo)的混合溶劑中合成的水凝膠的力學(xué)性能相對(duì)較好。另外可以針對(duì)通過溫度掃描測得的剪切模量、通過壓縮測試測得的壓縮模量以及通過原子力顯微鏡測得的楊氏模量進(jìn)行比較,因?yàn)檫@三種模量隨著合成時(shí)溶劑的甲醇摩爾分?jǐn)?shù)變化的趨勢相似。在第三章中,采用上述的方法研究了在相同合成的條件下具有不同共聚單體組分的P(NIPAM-co-NEAM)水凝膠隨溫度變化的流變學(xué)性能。結(jié)果證明LCST以及模量會(huì)隨著NIPAM共聚單體含量的增加而減少,這是因?yàn)轶w系親水-疏水平衡和凝膠形貌多孔性發(fā)生了變化。第四章是溶于苯甲醇中的PNIPAM有機(jī)凝膠的流變學(xué)基礎(chǔ)研究。通過溫度掃描的結(jié)果表明等規(guī)度或者濃度過低的PNIPAM樣品,在溫度掃描過程中無法形成凝膠,因此它們也沒有溶膠-凝膠轉(zhuǎn)換溫度。而對(duì)于其它樣品,它們的凝膠強(qiáng)度、溶膠-凝膠轉(zhuǎn)變溫度與分子量、等規(guī)度和濃度有關(guān)。由大應(yīng)變掃描測試可得知這種有機(jī)凝膠的線性黏彈極限會(huì)隨分子量、等規(guī)度、濃度的增加而趨于更小的應(yīng)變。第五章涉及由NIPAM和多巴胺丙烯酰胺的共聚物(NIDO)與NIPAM與4-乙烯基苯硼酸的共聚物(NIBA)兩種聚合物溶液的混合物形成的超分子凝膠(NIBA)的大幅振蕩剪切掃描測試,這種材料在兩種溶液不同混合比例的條件下,其線性和非線性流變學(xué)行為都有所不同。當(dāng)兩種聚合物溶液1:1混合時(shí)會(huì)形成強(qiáng)度最高的凝膠,而4:1混合物具有明顯較低的模量和截然不同的流變學(xué)行為。可以從Fourier變換流變學(xué)得到高次奇數(shù)次諧波強(qiáng)度比一次諧波強(qiáng)度的比例或者從Lissajous曲線的扭曲程度來評(píng)價(jià)材料的非線性程度。這些超分子凝膠與一般的聚合物熔體和溶液不同,這種超分子凝膠在過大的應(yīng)變時(shí),非線性程度會(huì)有所減小。
[Abstract]:The gel based on N-isopropylacrylamide (NIPAM) has a low critical dissolution temperature (LCST).) close to human body temperature. This property makes it a potential thermosensitive polymer gel material for drug delivery and biomedical engineering. Rheometer is an important tool for exploring soft matter materials such as gel, suspension and colloid in many instruments used to characterize gel. The gel forming temperature can be characterized by rheology, the mechanical properties and the response to the applied strain can be obtained. In this thesis, we synthesized a series of hydrogels or organic gels based on NIPAM and studied the properties of these gels from the point of view of rheology. The main contents of this paper are as follows: in chapter 1, we introduce the gel materials based on NIPAM. Rheology and the basic concept of rheometer. The second chapter mainly deals with the random copolymerization of NIPAM and NEAM (N-ethylacrylamide) in different methanol-water mixed solvents. Their LCST and mechanical properties were characterized by temperature scanning and uniaxial compression tests. The hydrogels synthesized in the mixed solvent dominated by water have relatively good mechanical properties. In addition, the shear modulus measured by temperature scanning, the compression modulus measured by compression test and the Young's modulus measured by atomic force microscope can be compared. Because the three moduli have a similar trend with the methanol molar fraction of the solvent. In chapter 3, the rheological properties of P (NIPAM-co-NEAM) hydrogels with different comonomer components under the same conditions were studied by using the above method. The results show that the LCST and modulus decrease with the increase of NIPAM monomer content, which is due to the change of hydrophilic-hydrophobic equilibrium and pore size of the gel. In chapter 4, the rheological basis of PNIPAM organic gels dissolved in benzyl alcohol is studied. The results of temperature scanning show that PNIPAM samples with low isotacticity or concentration can not form gels during temperature scanning, so they do not have sol-gel conversion temperature. For other samples, their gel strength and sol-gel transition temperature are related to molecular weight, isotacticity and concentration. The linear viscoelastic limit of the organic gel tends to decrease with the increase of molecular weight, isotacticity and concentration. Chapter 5 deals with the large oscillatory shear scanning test of (NIBA), a supramolecular gel formed from the mixture of (NIDO), a copolymer of NIPAM and dopamine acrylamide, and (NIBA), a copolymer of NIPAM and 4-vinylphenylboric acid. The linear and nonlinear rheological behaviors of this material are different under different mixing ratios of two solutions. When the two polymer solutions are mixed at 1:1, the gel with the highest strength will be formed, while 4:1 mixture has obviously lower modulus and distinct rheological behavior. The ratio of the intensity of higher odd harmonic to the intensity of first harmonic can be obtained from the rheology of Fourier transformation, or the degree of distortion of Lissajous curve can be used to evaluate the degree of nonlinearity of materials. These supramolecular gels are different from general polymer melts and solutions. The nonlinearity of these supermolecular gels decreases when the strain is too large.
【學(xué)位授予單位】：深圳大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O648.17
本文編號(hào)：2244770
[Abstract]:The gel based on N-isopropylacrylamide (NIPAM) has a low critical dissolution temperature (LCST).) close to human body temperature. This property makes it a potential thermosensitive polymer gel material for drug delivery and biomedical engineering. Rheometer is an important tool for exploring soft matter materials such as gel, suspension and colloid in many instruments used to characterize gel. The gel forming temperature can be characterized by rheology, the mechanical properties and the response to the applied strain can be obtained. In this thesis, we synthesized a series of hydrogels or organic gels based on NIPAM and studied the properties of these gels from the point of view of rheology. The main contents of this paper are as follows: in chapter 1, we introduce the gel materials based on NIPAM. Rheology and the basic concept of rheometer. The second chapter mainly deals with the random copolymerization of NIPAM and NEAM (N-ethylacrylamide) in different methanol-water mixed solvents. Their LCST and mechanical properties were characterized by temperature scanning and uniaxial compression tests. The hydrogels synthesized in the mixed solvent dominated by water have relatively good mechanical properties. In addition, the shear modulus measured by temperature scanning, the compression modulus measured by compression test and the Young's modulus measured by atomic force microscope can be compared. Because the three moduli have a similar trend with the methanol molar fraction of the solvent. In chapter 3, the rheological properties of P (NIPAM-co-NEAM) hydrogels with different comonomer components under the same conditions were studied by using the above method. The results show that the LCST and modulus decrease with the increase of NIPAM monomer content, which is due to the change of hydrophilic-hydrophobic equilibrium and pore size of the gel. In chapter 4, the rheological basis of PNIPAM organic gels dissolved in benzyl alcohol is studied. The results of temperature scanning show that PNIPAM samples with low isotacticity or concentration can not form gels during temperature scanning, so they do not have sol-gel conversion temperature. For other samples, their gel strength and sol-gel transition temperature are related to molecular weight, isotacticity and concentration. The linear viscoelastic limit of the organic gel tends to decrease with the increase of molecular weight, isotacticity and concentration. Chapter 5 deals with the large oscillatory shear scanning test of (NIBA), a supramolecular gel formed from the mixture of (NIDO), a copolymer of NIPAM and dopamine acrylamide, and (NIBA), a copolymer of NIPAM and 4-vinylphenylboric acid. The linear and nonlinear rheological behaviors of this material are different under different mixing ratios of two solutions. When the two polymer solutions are mixed at 1:1, the gel with the highest strength will be formed, while 4:1 mixture has obviously lower modulus and distinct rheological behavior. The ratio of the intensity of higher odd harmonic to the intensity of first harmonic can be obtained from the rheology of Fourier transformation, or the degree of distortion of Lissajous curve can be used to evaluate the degree of nonlinearity of materials. These supramolecular gels are different from general polymer melts and solutions. The nonlinearity of these supermolecular gels decreases when the strain is too large.
【學(xué)位授予單位】：深圳大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O648.17
【參考文獻(xiàn)】
相關(guān)期刊論文 前2條
1 Fumihiko Tanaka;Tsuyoshi Koga;Hiroyuki Kojima;Francoise M.Winnik;;HYDRATION AND PHASE SEPARATION OF TEMPERATURE-SENSITIVE WATER-SOLUBLE POLYMERS[J];Chinese Journal of Polymer Science;2011年01期
2 劉文博;王國明;蔡晴;金日光;;N-異丙基丙烯酰胺類共聚物溫敏性研究[J];高分子學(xué)報(bào);2008年12期
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