【作者】 钱镇；

【导师】 张志成；

【作者基本信息】 中国科学技术大学 ， 高分子化学与物理， 2009， 博士

【摘要】 本论文首先合成了Y型表面活性剂及其衍生物,并研究了其作为稳定剂在辐射（细）乳液聚合中的应用和磁性复合材料制备上的应用;其次,合成了Gemini型表面活性剂并研究了其作为稳定剂在辐射细乳液聚合中的应用;最后研究了单分散表面羧基功能化聚苯乙烯微球在制备单分散生物可降解中空微球和制备树莓型微球构筑超疏水性材料方面的应用。论文的主要工作和结果分别叙述如下:一、Y型表面活性剂的合成及其表面活性的研究,以及其在辐射乳液聚合中的应用和磁性复合材料制备上的应用（一）首先优化了Y型表面活性剂及其衍生物的合成、提纯路线,最终制备了纯的Y型表面活性剂及其新型衍生物,并对它们进行了红外、核磁氢谱表征。通过测定浓度一表面张力曲线的方法研究了Y型表面活性剂及其衍生物在pH=9时各自的CMC值。试验结果显示,随着Y型表面活性剂侧基从乙酰氧基到苯酰氧基,侧基的体积逐渐增大,而CMC值从6.39*10^-5g/ml增大到4.16*10^-4g/ml。（二）研究了γ射线引发Y型表面活性剂作为单一稳定剂稳定的乳液聚合前后粒径变化、动力学情况和聚合后体系表面张力的研究,证实了Y型表面活性剂作为单一稳定剂时,由于其具有很长的疏水链（18C疏水链加上4～7C侧基）,在细乳液聚合时既能起到稳定液滴的同时,也能起到助乳化剂控制渗透压,抑制Ostwald ripening的作用。（三）研究了不同Y型表面活性剂制备丙烯酸铵反相乳液的稳定性,试验结果表明随着Y型表面活性剂疏水链侧基体积的增大,反相乳液稳定性大大提高。不同表面活性剂所配置的反相乳液的稳定性大小排列为AcOA＜BOA=IBOA＜HOA=Span-80＜BzOA。在反相乳液中引入油相单体在油水界面聚合,成功制备了聚丙烯酸铵/聚苯乙烯核壳粒子。并研究了在通过干燥除去交联聚丙烯酸铵核中溶胀的水相后,核壳粒子变成红血球型微球的现象及其机理。（四）研究了辐射细乳液聚合制备Y型表面活性剂改性磁性Fe₃O₄/聚苯乙烯复合微球。使用Y型表面活性剂（HOA）对磁性Fe₃O₄粒子表面进行了改性后,通过γ射线引发磁性Fe₃O₄粒子/苯乙烯细乳液聚合制备Fe₃O₄/PSt复合微球。通过改变计量率,助乳化剂（HD）含量,磁性粒子含量,Y型表面活性剂含量等影响因素,最终获得了粒径分布较窄高磁含量的Fe₃O₄/PSt复合微球,并对复合微球进行了XRD,FTIR,TEM,HRTEM,FESEM,TGA,XPS,HL等表征。并通过对动力学的研究,探讨了γ射线引发磁性Fe₃O₄粒子/苯乙烯细乳液聚合的机理。二、Gemini型表面活性剂的合成及其在辐射乳液聚合中的应用。首先合成了不同链长的聚乙二醇作为联接链段的gemini型表面活性剂,研究了γ射线引发不同gemini型表面活性剂作为稳定剂稳定的细乳液聚合对生成的PSt乳胶粒子的影响。试验结果显示,随着分子中PEG分子链长从0增加到4000,所得到的PSt乳胶粒子粒径逐渐增大。同时,研究了γ射线引发不同gemini型表面活性剂作为稳定剂稳定的细乳液聚合的动力学情况。三、单分散表面羧基功能化聚苯乙烯微球在制备单分散生物可降解中空微球和制备树莓型微球构筑超疏水性材料方面的应用。（一）首先通过无皂乳液聚合制备了不同表面羧基功能化的单分散聚苯乙烯微球作为模板,然后通过相反离子电荷的作用将壳聚糖一步沉积到模板并交联,最后除去模板得到交联壳聚糖中空微球。这一方法比LBL法更为方便有效,因为LBL法在多步沉积过程中可能破坏中空微球的结构。其中,交联壳聚糖微胶囊的壁厚和形貌可以通过改变聚苯乙烯微球表面羧基功能化程度来控制,交联壳聚糖微胶囊的尺寸也可以通过聚苯乙烯微球的尺寸来控制。从FESEM和TEM的照片中也可以看到中空微球的形成。最后,我们通过延长交联反应时间得到了结构规整尺寸均一的交联壳聚糖中空微球,并用它做了体外药物释放试验。（二）将羧基功能化聚苯乙烯微球引入到正硅酸乙酯（TEOS）的水解过程中,简单高效地制备出了树莓型微球。我们通过增加羧基化功能聚苯乙烯微球表面的PAA含量,发现了生成的树莓型微球表面上的二氧化硅粒子从124 nm到36 nm可控,并对树莓型微球进行了XRD,FTIR,FESEM,TEM,XPS等表征。试验结果表明,表面上二氧化硅微球粒径越小的树莓型微球构筑的界面具有更好的超疏水性能。更多还原

【Abstract】 In this thesis,firstly,we synthesized a series of Y shape surfactants and investigated their application inγ-ray radiation induced（mini）emulsion polymerization and in preparation of the magnetite/polystyrene（PS） composite materials.Then,we synthesized a series of Gemini surfactants and investigated their application inγ-ray radiation induced miniemulsion polymerization.We also prepared monodisperse carboxyl- functionalized polystyrene particles for preparation of biocompatible microcapsules and investigated their application in the preparation of raspberry-like particles for the construction of superhydrophobic particulate film. The main results obtained in this dissertation are described as follows:1.The synthesis of Y shape surfactants and their application inγ-ray radiation induced（mini）emulsion polymerization and in the preparation of the magnetite/polystyrene composite materials.1) A series of Y shape surfactants were synthesized and characterized by FT-IR and ¹H-NMR spectra.We measured the Critical Micelle Concentration（CMC） value of the Y shape surfactants at pH=9 in the water.The results showed that with increase of the volume of the Y shape surfactants’ branched groups,the CMC value increased from 6.39* 10^-5g/ml to 4.16* 10^-4g/ml.2) We investigated the preparation of PS latex particles from radiation induced miniemulsion polymerization using Y shape surfactants as the sole stabilizer. The surface tension of the latexes were investigated,kinetics analysis shows that there is no constant rate stage which seems to indicate a droplet nucleation mechanism.TEM and LPZPA were used to observe the polystyrene latex particles and original droplets,respectively.The results showed that the emulsifiers act not only as the surfactants,but also as the so-called "cosurfactant".3) We investigated the stability of ammonium acrylate inverse emulsion using Y shape surfactants as stabilizers.The results showed that with increase of the volume of the Y shape surfactants’ branched groups,the stability of the inverse emulsion increased.The stability of the inverse emulsion by: AcOA<BOA= IBOA<HOA= Span-80<BzOA.We also prepared the PS shell and poly（ammonium acrylate） core microspheres by introducing styrene monomer as the part of oil phase into ammonium acrylate inverse emulsion polymerization.The core/shell microspheres changed into erythrocyte shape microspheres after dried and the formation mechanism was proposed.4) We modified the magnetite nanoparticles（MPs） with Y-shape surfactant: 12-hexanoyloxy-9-octadecenoic acid（HOA）.Nanocomposite microspheres consisting of polystyrene-iron oxide nanoparticles then were prepared by the radiation induced miniemulsion polymerization of styrene in presence of HOA modified MPs using HOA as stabilizer.The final products were characterized by X-ray powder diffraction（XRD）,Fourier transform infrared spectroscopy （FT-IR）,field-emission scanning electron microscopy（FESEM）, thermogravimetric analysis（TGA） and X-ray photoelectron spectroscopy （XPS）.The effects of the dose rate,the added amount of hexadecane（HD） and MPs,and the morphology of the final products were studied.We have also studied the polymerization kinetics to prove the miniemulsion polymerization mechanism of the nanocomposite microspheres.2.The synthesis of Gemini surfactants and their application in the radiation induced miniemulsion polymerization.We synthesized a series of Gemini surfactants with different PEG chains as link chains.Then,we investigated the preparation of PS latex particles from radiation induced miniemulsion polymerization using Gemini surfactants as the stabilizer.The results showed that with increase of the PEG chains, the diameter of the PS latex particles increased.Also we investigated the kinetics of the miniemulsion polymerization.3.We also prepared monodisperse carboxyl- functionalized polystyrene particles for the preparation of biocompatible microcapsules and for their application in the preparation of raspberry-like particles for the construction of superhydrophobic particulate film.1) A strategy for the fabrication of hollow crosslinked chitosan microspheres with carboxyl-functionalized polystyrene particles as template was proposed. It involves an initial depositing and cross-linking of chitosan on the surface of carboxyl-functionalized latexes followed by removal of the core.It is more convenient and effective than LbL assembly because the deposition is just one-step.The degree of carboxyl-functionalization at the surface of the latexes and the cross-linked time play the important roles in the formation of the hollow microspheres.Results from FESEM and TEM revealed the formation of hollow microspheres.At last,we get the monodisperse hollow chitosan microspheres by increasing the degree of carboxyl-functionalization at the surface of the latexes and the cross-linked time.In addition,the invitro release behavior of a water-soluble drug encapsulated in the microcapsules was investigated.2) A new strategy was developed to prepare raspberry-like particles by introducing poly（acrylic acid）（PAA）-functionalized polystyrene（PS） particles into hydrolysis reaction of tetraethoxysilane（TEOS）.The monodisperse PAA-functionalized PS particles were used as cores and nanosized silica particles were then assembled at the surface of PS particles to construct the raspberry-like particles during the hydrolysis process.With the increase of PAA content from 11%to 20%（wt） at the surface of latexes,the diameter of the silica particles assembled at the surface of cores decreased from 124 nm to 36 nm.The structure,morphology and constitution of the raspberry-like particles were characterized by XRD,FTIR,FESEM,TEM and XPS.The results showed that the increase of scale ratio of the micro/nano surface structure is beneficial to improve the surface superhydrophobic performance.更多还原