丙烯酸系亲水聚合物的分子设计、制备及应用研究

发布时间：2018-09-12 17:00

【摘要】：合成亲水高分子,因其原料易得,结构和性能可控而在增稠、吸水树脂及智能微凝胶等方面得到广泛应用。进一步提高水凝胶的吸水性及使用安全性、赋予聚合物高效性、功能性、智能性成为该领域的研究热点。本论文基于丙烯酸及共聚物展开,设计并制备了一系列功能性亲水聚合物,并对其结构和性能进行了详细地表征和研究。(1)化学交联丙烯酸微凝胶的合成与应用研究。使用沉淀聚合法,将丙烯酸与三官能单体季戊四醇三烯丙基醚共聚,合成主要用作水性增稠剂的丙烯酸微凝胶。通过核磁共振、红外光谱、扫描电镜对凝胶结构进行了表征,并对凝胶的动态模量、粘度、透光率、聚合稳定性等方面进行了研究。结果表明,在聚合温度为68oC,交联剂用量为单体质量分数的0.4%,单体浓度为14%,分散剂用量为单体质量分数的1.2%,引发剂LPO用量为单体摩尔分数的0.15%时,所得丙烯酸均聚物微凝胶综合性能最为优异,其0.5%凝胶分散液粘度为8.08×104 mPa·s,0.2%分散液粘度为1.45×104mPa·s,透光率为97.4%。同时,采用与具有长疏水链的单体丙烯酸十八酯共聚,改善其凝胶的耐盐性及抗稀释性。结果表明,通过疏水单体丙烯酸十八酯的共聚改性,在分子网络中形成物理交联点,可提高凝胶的耐稀释性、耐盐性等流变学性质;尽管添加共聚单体会使粉末润湿时间提高,但当共聚单体添加量为3%时,凝胶于低浓度、酸碱环境、离子环境、有机溶剂环境、较高温度下具有优异的流变学性质。(2)基于配位作用的超分子凝胶的合成与性能。对2,2':6',2″-三联吡啶的苯基4'位进行修饰,形成含有可聚合双键的4'-(苯乙烯基)-2,2':6',2″-三联吡啶单体,将此单体与丙烯酸共聚,即得水溶性的含三联吡啶配体基团的线性聚合物,在水溶液中可迅速与过渡金属离子配位形成超分子凝胶。由特性粘数、动态流变、吸水倍率、热分析及微观形貌分析对溶胶及凝胶性能进行测试表征,并将配体配制成低浓度溶液,以微量金属离子络合,进行光谱性能的测试研究。结果表明,高浓度配体溶液可瞬间与金属离子配位形成三维结构,溶胶和凝胶的动态模量发生大幅转变;且凝胶表现出智能环境响应性,酸碱和离子环境可降低凝胶吸水倍率,但其交联结构并未因此破坏,表明金属配位键具有一定的结合强度。将低浓度配体溶液及络合物进行光谱测试,结果表明,配体溶液的紫外-可见吸收峰值为305nm,分别添加一定浓度的Fe2+、Ni2+、Cu2+、Cd2+、Zn2+,其吸收峰值发生不同程度的红移,吸收强度也有一定的变化,并在某些离子浓度区间具有比较明显的线性关系;配体具有荧光发射性能,而Fe2+、Ni2+、Cu2+可使配体荧光猝灭,配体与Cd2+、Zn2+络合后具有荧光发射,并使荧光发射峰值红移。该类分子显示出优异的离子传感功能,可望在水体系中对特定金属离子的痕量分析方面得到应用。
[Abstract]:Hydrophilic polymers are widely used in thickening, absorbent resins and intelligent microgels due to their easily obtained raw materials, controllable structure and properties. Further improving the water absorption and safety of hydrogels and endowing polymers with high efficiency, functionality and intelligence has become a research hotspot in this field. A series of functional hydrophilic polymers were designed and prepared based on acrylic acid and copolymers. The structure and properties of these polymers were characterized and studied in detail. (1) Synthesis and application of chemically crosslinked acrylic microgels. Acrylic acid microgel was synthesized by precipitation polymerization of acrylic acid and trifunctional monomer pentaerythritol triallyl ether. The structure of the gel was characterized by NMR, IR and SEM. The dynamic modulus, viscosity, transmittance and polymerization stability of the gel were studied. The results show that when the polymerization temperature is 68oC, the amount of crosslinking agent is 0.4wt% of monomer, the concentration of monomer is 14%, the amount of dispersant is 1.2 mass fraction of monomer, the amount of initiator LPO is 0.15 mol fraction of monomer. The obtained acrylic acid homopolymer microgel has the most excellent comprehensive properties, the viscosity of 0.5% gel dispersion is 8.08 脳 10 ~ 4 mPa / s, the viscosity of 0.2wt% dispersion solution is 1.45 脳 104mPa / s, and the transmittance is 97.4%. The salt resistance and dilution resistance of the gel were improved by copolymerization with octadecyl acrylate, a monomer with long hydrophobic chain. The results show that the physical crosslinking point can be formed in the molecular network by copolymerization modification of hydrophobic monomer octadecyl acrylate, which can improve the rheological properties of gel, such as dilute resistance and salt resistance, although adding copolymer monomer can increase the wetting time of powder. However, the gel has excellent rheological properties at low concentration, acid-base environment, ionic environment, organic solvent environment and higher temperature when the amount of monomer is 3. (2) Synthesis and properties of supramolecular gel based on coordination. The phenyl 4 'site of 2o 2: 6: 6 "-tripyridine was modified to form a 4n- (styrene group) -2o 2: 6: 6" -tripyridine monomer containing polymerizable double bonds. The monomer was copolymerized with acrylic acid to form a water-soluble linear polymer containing tripyridine ligand group. Supramolecular gels can be rapidly coordinated with transition metal ions in aqueous solution. The properties of sol and gel were characterized by intrinsic viscosity, dynamic rheology, water absorbency, thermal analysis and micromorphology analysis. The ligand was prepared into a low concentration solution, and the spectral properties were studied by complexing with trace metal ions. The results showed that the solution of high concentration ligand could coordinate with metal ions to form three dimensional structure, and the dynamic modulus of sol and gel changed greatly, and the gel showed intelligent environmental response, and acid base and ion environment could reduce the absorbency of gel. However, the crosslinking structure was not destroyed, indicating that the metal coordination bond has a certain binding strength. The spectra of low concentration ligands and their complexes were measured. The results showed that the UV-Vis absorption peak value of ligand solution was 305 nm, and the absorption peak value of ligands was shifted to different degrees by adding certain concentration of Fe2 Ni2 / Cu2 / CD2 / Zn2 / Zn2 +, respectively. The absorption intensity of ligands also changed, and the linear relationship was obvious in some ion concentration ranges. The ligands have fluorescence emission properties, while Fe2 Ni2Cu2 can quench the fluorescence of ligands, and the ligand complexes with Cd2 + Zn2 + have fluorescence emission, and the luminescence of ligands can be quenched when the ligands are complexed with Cd2 ~ (2 +) Zn _ (2). And the fluorescence emission peak red shift. These molecules exhibit excellent ion sensing function and are expected to be applied to trace analysis of specific metal ions in water systems.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O648.17

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